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Houston, we have a blow out!

I think we have all experienced a bubble/blow-over brew at some point in our brewing life, all in varying degrees of disaster. I’ve seen chest freezers absolutely covered in worty mess, but sometimes it’s slightly less disastrous, where it has gone only as far as your bubbler. This is why it always a good idea to have one bubbler spare.



The reason for a bubble over is a lack of headspace in your fermenter and the krausen has escaped. Many brewers forget that high gravity brews (anything above 1.060 OG in my opinion) need extra headspace in the fermenter. But even lower gravity brews can blow over if the fermentation is particularly vigorous, usually caused by higher fermentation temperatures or increased aeration etc.

So what do you do?

Don’t panic! It looks worse than it is. Get a spray bottle of sanitiser and do your best to sanitise and clean the outside of the fermenter and surrounds. Only deal with the bubbler/blow off tube once the fermenter and surrounds are clean and sanitary. You don’t want to open the fermenter at all. Transferring your worty beer into a clean fermenter will only harm your brew at this point. Your fermenter will look like a dog’s breakfast on the inside, but it’s a yeasty/worty/hoppy dog’s breakfast, so rather leave it. You can always transfer into a secondary bucket on bottling day.

Once the outside of your fermenter is clean and sanitised, you can swap over to a clean bubbler, or blow off tube of the same diameter as the bubbler (so that it fits snuggly). When you do this, make sure the replacement bubbler/blow-off tube has been properly sanitised. If the rubber bung that holds the bubbler is also mucky, then I would suggest using a cotton bud or cotton wool, also sanitised thoroughly, to gently swab it clean. Cane or Vodka also works very well for this, if you are worried about the sanitising solution getting into your brew. The opening where the bubbler fits is very small, so it is not likely for any nasties to sneak inside during this process, but I would still try and work quickly, and work in an area that is not too draughty. Replace your bubbler, fill with a little alcohol or sanitiser to create an airlock, and you’re good to go again.

Alternatively you can use a blow off tube, place the end of the tube into a bucket of sanitiser solution so nothing gets into your fermenter via the tube.


Written by Megan Gemmell — March 14, 2016

Making a yeast starter

Growing up your own yeast and maintaining your stocks can be a very daunting concept, but if you follow a few simple steps, you will find that it is not that intimidating. Provided you keep things
sanitary, you will soon be benefiting from the rewards (faster fermentations and cleaner beers) of
pitching live yeast at the correct pitch levels.



  • Erlenmeyer flasks (2 liter is a good size)                
  • Stir plate  
  • Stirrer bar
  • Dry malt extract
  • Yeast nutrient
  •  Hops (your old expired ones will do perfectly)
  • Camping gas stove/Bunsen burner
  • Spray bottle of sanitiser


Sterilizing wort in the flask:

The best starting gravity for your starter is 1.036 to 1.040. You can sterilise your flask, stirrer bar
and wort by simmering directly on your stove top for approximately 45 minutes with a cotton-
wool bung (acts like a filter to stop anything getting in) covered with tin foil, and then a further 40
minutes the following day (a method of tyndallization) (of course, you will need to take into
account any boil-off during this process, and thus you will need to reduce your initial starter
gravity to avoid an OG too high). Adding a few hop pellets into the wort before sterilising adds a
further method of keeping contamination out (hops are a natural antimicrobial agent). You can  also sterilise top-up wort in a pressure cooker if you have one. This acts like a mini-autoclave and is very effective. 


Inoculating your starter with yeast:
You can use either dry yeast (such as Fermentis), or liquid yeast (Wyeast or Whitelabs). To scale
dry yeast up in volume, you would normally follow a rehydration step in 27°C ± 3°C sterile water
or wort for 15-30 mins, and then you would add this yeast to the starter. Liquid yeast has a much
shorter shelf life than the dehydrated yeast, and therefore, more commonly needs a starter.

To ensure your starter stays clean of contamination, there are a few things you can do. Sanitise
your work area around you as well as your hands before starting. Have your Bunsen burner or
camping gas burner lit and close by. Each time you remove the cotton-wool and tin foil bung, you
need to flame the neck of the flask, this ensures that if any contamination is on the neck of the
flask, you will kill it, and it also allows for a steady rise of hot air away from the open flask, to
prevent any bacteria/wild yeast settling on your flask.

If you are growing up a sachet of dry yeast, sanitise the outside of the sachet as well as the scissors you will use to open it, with acidisan (or equivalent). If you are using a liquid culture in a vial, then sanitise the outside of this too. These vials are usually plastic, so you won’t be able to flame the edges of it, you just need to work quickly in decanting it into your flask, and try to work as near to the flame as possible. Once you have added the yeast into the flask, flame the neck of the flask again, and replace the cotton wool and tin foil bung. It is usually required that you let the flask containing the newly added yeast to sit on a table top for approximately 30 minutes, before placing it on the stir plate for the growth stages. You can scale up the yeast even more by adding sterile wort into the flask following the same sterile technique discussed above. If need be, you can decant some of the spent wort from your flask to make space for fresh wort to continue its growth. I always taste the spent wort to get a gauge on how the yeast is doing.

With this, you should be all set to grow your own yeast starters. Good luck!

Written by Megan Gemmell — January 27, 2016

Selecting the “right” yeast

Yeast belongs to the fungal kingdom and are unicellular. There are about 1500 different strains of yeast, but brewer’s yeast is very different to those yeasts found in the wild. Many yeast strains can convert sugar to carbon dioxide and alcohol, but this does not necessarily mean they can make good beer. Brewing yeast has, essentially, been domesticated. In other words, we have purposefully selected for characteristics such as the ability to grow and feed off malted grains quickly, and to provide the desired beer flavours and aromas.

    During fermentation, yeast breaks down simple sugars to harvest energy for its survival, and produces carbon dioxide and alcohol, which for us, are the desired waste products. It is believed that yeast evolved this ethanol-CO2 producing ability, to prevent other microbes from also feeding on the simple sugars, as the very high acidity and alcohol levels make the environment intolerable for most organisms. This is great for us brewers.

    There are hundreds of different strains of brewing yeast, but you want to choose a strain that creates the best flavours in your beer, and not all strains will be suitable to your needs. Both literature and the web are full of helpful information regarding which yeast strain to choose for your beer.

    There are two main species of brewing yeast, namely, ale (S. cerevisiae) and lager (S. pastorianus) yeast, and within these 2 main species, there are many different strains, all producing various characteristics to a beer.

    George Fix helpfully categorised ale and lager yeasts according to their fermentation character (flavours etc) rather than by region:

    • Lager  - Dry/Crisp
                  - Full/Malty
    • Ale       - Clean/Neutral
                   - Fruity
    • Phenolic
    • Hybrid (these beers lie between the ale and lager style)
    • Eccentric (these strains produce unusual flavour compounds such as earthy, barnyard, sour or are high gravity fermenting yeasts.

    Ale strains are top fermenting (produce a large, foamy head/krausen). This is because the ale yeast surfaces are hydrophobic and the yeast cells stick to the CO2 bubbles and rise with them to the surface. They usually ferment at about 18-21⁰C.

    Lager strains are sometimes referred to as “bottom-fermenting” as during fermentation, they don’t rise (or only minimally) to the surface. They are also not usually very good flocculators, so they tend to stay in suspension for longer than the ale yeasts. This allows the yeast to reduce more of the by-products that are formed during fermentation. This results in the “clean lager” character we commonly speak of. They usually ferment between 11 and 12⁰C.

    So, how do you choose? Well, you first need to decide what the overall concept is that you want from your beer. Do you want malty and sweet, crisp and dry, clean or estery (fruity), high or low alcohol etc? Once you have decided, you can begin looking at possible yeast strains. Over the last year or so, new and exciting yeast strains have entered the South African market, so you now have a lot more choice to play with. It is daunting to begin with, but once you know what you’re dealing with, you can have a lot of fun trying the different styles. It really is amazing how much character a yeast strain can impart on a beer (see previous blog). The most important things to consider are:

    • Attenuation (do you want crisp or malty/sweet)
    • Flavour profile (clean, spicy, malty or fruity etc)
    • Flocculation (how well a yeast settles out of suspension)
    • Supply/availability
    • Temperature range (this is important if you don’t have access to temperature control)

    You can chat to your brewing buddies, look at literature, search online, or you can play with the different yeast strains yourself and pick the best one. You can do this by brewing a batch and splitting it into a number of fermenters with different yeast. Once you’ve decided on a strain, you can then manipulate temperature, oxygen levels, pitching rates and determine what has the best effect on your finished beer.

    Most yeast suppliers make our decisions easier by differentiating the yeast by ale or lager first, and then by geographic location (country, city, or region) or by its specific style name (eg: Altbier, California Common etc). Once you’ve narrowed it down, you can decide from there. But don’t limit yourself to just these. You can brew an American pale ale using a European ale yeast, for example. This will set your beer apart from all the other APA’s, and give you a lot more yeast strains to play with. Don’t be afraid to experiment.

    Good luck, and have fun!



    White, C., Zainasheff, J. 2010. Yeast: The practical guide to beer fermentation. Brewers Elements Series, Brewers Publications. 304 pp.

    Reid, A., Ingerson-Mahar, M. 2012. If the yeast ain’t happy, ain’t nobody happy: The microbiology of beer. American Academy of Microbiology, Washington, DC. 13 pp.

    More about the Author, Megan Gemmell:

    When I am not working as a microbiologist, I am brewing and studying beer. Being the geek scientist that I am, brewing yeast has become one of my main interests. After many years of brewing on my home-made system, squeezed into the laundry, I have taken the plunge and started Clockwork Brewhouse, and I’m loving it. 

     Visit Clockwork Brewhouse

    Written by Megan Gemmell — April 22, 2015

    Happy yeast is happy beer: are you pitching correctly?

    Many brewers are daunted by the idea of yeast starters, but with a few basic tips and a bit of practice, you won’t look back. Over the course of the next few months, I will cover the basics of yeast, from propagation, to its health.

    The most important lesson I have learnt while brewing, and I cannot stress it enough, is keeping your yeast happy. Happy yeast is happy beer. It is almost like yeast is the afterthought after a long, tiring day of brewing, and few of us realise the importance of choosing the correct yeast, and knowing how to keep it happy. Many of us are not pitching the correct amount of yeast into our wort. Either we are on a budget, or we are just guesstimating, and don’t really know where to start. Once I discovered the importance of pitching the correct amount of yeast, I have never looked back. I achieved a noticeable improvement in the resulting beer: it fermented faster, aging time was massively reduced (you’ll get to drink it so much faster ), and there was a clear reduction in unwanted yeast by-products, such as acetaldehyde (green apples). In addition to all these benefits, correct pitching rates also help to prevent potential contamination by wild-yeast or bacteria that may have snuck in (such as Pediococcus and Lactobacillus). By starting with a high number of yeast cells, you are reducing the likelihood of any potential foreign microbes from replicating sufficiently to outcompete the brewing
    yeast and become a problem. (However, please note, if your cleaning process is not adequate, no amount of yeast will prevent a contaminated beer).

    First off, you need to remember that yeast is a living organism, and, like us, it needs nutrients and minerals to stay fit, strong and happy. This comes in the form of sugars, nitrogen, amino acids and fatty acids (majority of which comes from the malt, but also from specific yeast nutrients such as the
    Servomyces Yeast Nutrient). In addition, yeast, like us, does not perform well under stress. Yeast can be stressed by numerous things, such as high sugar concentrations, low pitch rates, incorrect reproduction/fermentation temperatures, pH etc. Ensuring you have created the best environment for
    the yeast, you will massively improve the quality of the resulting beer.

    For the purposes of this blog, I am going to concentrate on pitching rates.
    Mr Malty (  is an invaluable tool to help you calculate the correct pitching rates for your brew. After playing with the calculator, you will soon see that the suggested pitching levels stated on most dehydrated sachets of brewing yeast are actually too low (11.5g per 20-30 liters). To use an example, you need 10g of dry yeast for 20 liters of 1.050 gravity wort. Baring in mind, this is using yeast that was produced on the 3 March 2015 (maximum viability).


    However, most dry yeast we purchase are already a few months old. So remember to take that into consideration, as you will then need to pitch more yeast. For a 6 month old sachet, you would then need 12g of yeast.


    Lagers require a higher pitching rate than ales (the reasons will be covered in a future blog). For a 20 liter lager of 1.050 starting gravity, you need 21g of dehydrated yeast (of the same viability as the ale as previous). This is over double the amount of yeast that is required for an ale. (Remember, stronger beers also require a higher pitching rate).

    And for a 6 month old sachet, you will need 23g for your 20 liter lager.

    Under pitching causes the yeast to reproduce a lot more than a higher pitch would, before all the resources are consumed. This results in a beer that has more yeast character (esters etc.), while those beers that are pitched higher tend to have a cleaner fermentation with less yeast character.

    Belgian-style and wheat beers (eg. Weiss) add a whole new aspect to your approach to yeast however, and defy everything I have just told you. What makes these beers unique, is their fruitiness (eg. banana- called esters) and their spiciness (clove-like- called phenols). What gives these beers their
    characteristics, is playing with the fermentation temperatures, their starting gravity, and pitching rate and achieving the correct balance. Higher fermentation temperatures results in more esters produced (more fruity/banana like aromas), while more phenols are produced at lower fermentation
    temperatures (spice/clove-like aromas). Some Belgian breweries start at a lower fermentation temperature for phenol production, and then allow the fermentation temperature to slowly increase, thereby increasing the production of esters. Each brewery has their own balance of esters/phenols for
    their beer. Just a side note, don’t ever decrease the fermentation temperature once fermentation has begun, this causes the yeast to go into survival mode, and drop out or go to sleep (stuck fermentation) (yeast does not like to be wrangled). You may need to re-pitch with healthy yeast. (As a home-brewer, it is advised to stick with the suggested fermentation temperature for your specific yeast). In addition, a reduction in your aeration will increase the production of esters, while increased aeration will reduce esters. Pitching rates also alter ester production. Some brewers like to under-pitch to increase fermentation characteristics in their beer. It is all about achieving a balance between all these parameters to reach your goal profile.

    After saying all this, there is also such a thing as too much yeast. Extreme over pitching causes the yeast to consume the nutrients too quickly, causing starvation, the build-up of unused metabolic products and yeast death, all of which will add unwanted characteristics to your finished beer.

    Of course, pitch rate is just the beginning of the yeast story. Yeast health, available nutrients, pH and fermentation temperature are all contributing factors in achieving great beer, but realising yeast is a living organism that needs a little TLC (tender, loving care) is the first giant step in the right direction to achieving great beer. Till next time, keep on beering! Megan


    More about the Author, Megan Gemmell:

    When I am not working as a microbiologist, I am brewing and studying beer. Being the geek scientist that I am, brewing yeast has become one of my main interests. After many years of brewing on my home-made system, squeezed into the laundry, I have taken the plunge and started Clockwork Brewhouse, and I’m loving it. 

     Visit Clockwork Brewhouse


    Written by Megan Gemmell — March 10, 2015

    It floats! A practical guide to using your hydrometer effectively!


    Of the two scientific instruments most commonly used by home brewers the hydrometer is certainly the least well understood. We all understand thermometers -temperature degrees are a part of everyday life. But what about relative density, specific gravity or degrees Plato? And then there’s that mysterious meniscus!  Using a hydrometer correctly takes much of the guess work out of brewing and is an indispensible measuring tool. This article will explain how -and also when- to use your hydrometer, to really get the most from it!

    For brewers the hydrometer achieves three simple tasks. It allows a way of determining the sugar content of the wort; monitor the progress of fermentation, and, with some simple maths, to calculate the alcohol content of the finished brew. For grain brewers, it can also help measure how efficiently the mash extracts sugars.

    A hydrometer reading is literally a calibrated measurement of how high (or low) it is floating in our wort or beer. This reading is higher in denser liquids, and lower in thinner ones. -So what makes a liquid denser? In this case it is dissolved maltose sugar (and some dextrin) that float the hydrometer higher, and later, as yeast gradually depletes the sugar, drop it lower.  Pretty simple- but how do we make this work for us?

    Calibration, readings and temperature

    Firstly let’s take a closer look at how hydrometers are calibrated. Specific Gravity (S.G.) is how home brewers measure the density of their wort or beer. This is a weight measurement, and is relative to pure water, which represents a reading of zero; this is written in Specific Gravity as 1.000. A 10 percent weight of sugar to weight of water gives us a reading of 1.040. The S.G. is often written as 1040 or simply 40.  Brewers simply refer to this as a ‘gravity reading’, and use two common abbreviations according to when the readings are taken during the brewing cycle. They are:  Original Gravity (O.G.) and Final Gravity (F.G.). The O.G. reading is taken before fermentation commences and the F.G. at the very end.

    So how do we actually take a reading? A hydrometer is supplied (usually) with a tall measuring flask. This holds enough liquid to float the hydrometer in without it touching the bottom. A sample of wort or beer is taken and the hydrometer floated in it (this is best done over a sink). Place on a counter and wait a few seconds for it to come to rest. Then take a reading from the surface of the water- not where the water meniscus reaches up! You now have a specific gravity reading- remember to write it down on your recipe sheet!

    A quick word about the temperature:  Modern hydrometers are typically calibrated to read at 20C and a higher or lower temperature liquid affects the accuracy. In practical terms a few degrees either way is not that noticeable, but larger jumps of 5-10 degrees should be taken into account. A warmer temperature of 32C (typical of warm wort) would give a difference of plus 1.003. Our reading of 1.040 would actually be 1.043.  This is because warm dissolved sugar isn’t as dense, and this affects the reading. Cooler temperatures give the opposite effect- at 10C you would minus 1.002 from 1.040 giving you 1.038. A calibration chart or online calculator is useful to make adjustments when necessary.

    What to expect

    Brewers take an Original Gravity sample reading before the fermentation has begun and the temperature is close to room temperature (18C-22C). The sample is then discarded or tasted, but never returned to the fermenter. The likelihood of contamination is too great a risk for the few mils of lost beer! To give you an idea what to expect, for a beer of average strength an O.G. reading would typically be between 1.042-1.058.

    There is a common habit amongst beginner brewers to take several sample readings towards the end of the fermentation to ascertain progress (and from curiosity). This is well and fine if your fermenter is equipped with a tap, but if it means opening the fermenter each time, rather avoid doing so, as it opens the beer to airborne contaminants like wild yeast and bacteria. The less you putz with your beer the better!

    Experienced brewers will usually wait the full 14 days until fermentation is completely finished and only then take the F.G. reading, usually before commencing bottling or kegging. At this stage it’s easy to see ( and taste) whether there has been a problem with the fermentation or not. ( For more information on this see the article”Is my beer ready yet?”).

    Confusion can often arise at this stage, as the gravity reading may seem too high, even though the beer has stopped fermenting. The reason for this is un-fermentable complex sugars and dextrin. These add flavour and body to your beer, and, as the yeast cannot break them down, they remain in solution and cause the reading to be higher. Beers typically finish anywhere from 1.005 to 1.016, with drier beers on the low side, and rich malty ones fairly high. As a general rule the F.G will be 20-25% of the O.G. for example a 1.040 beer will read 1.010 at the end of fermentation.

    If your gravity reading seems higher than expected (according to recipe or experience), let the beer ferment a little longer. Always be cautious, as unfermented beer can over-carbonate bottles or-even worse- cause them to explode!

    Recipes, Target Gravity and Alcohol by Volume

    Where our hydrometer really comes into its own is when working with recipes. Any good recipe will supply the expected O.G. and F.G for the beer. And, with experience it becomes possible to hit these numbers exactly (or be only one or two degrees out at most). Brewers refer to these as ‘target gravities’ and each beer style has its own typical range.

    For example, from the BJCP Style Guidelines here are the average gravities for a Dry Stout: O.G.1.036 to 1050, and F.G. 1.007 to 1.011. Knowing this, if your O.G. was 1.065 it would mean you were brewing a stronger beer than the style usually is – something more like a Foreign Extra Stout in fact (O.G.  1.056-1.075)!. A higher original gravity can often means a higher final gravity, especially with malty beers.

    From your two readings, determining the alcohol content is surprisingly easy. To do so, subtract your F.G. from your O.G. drop the decimal and multiply by 0.129. This will give you the standard Alcohol by Volume percentage.

    E.g.: O.G. 1.058 - F.G. 1.016 = 0.042              42 X 0.129=5.41% ABV

    And there you have it- a quick tour of the hydrometer! To cap off, it’s interesting to note that on many hydrometers there is a choice of calibrations. Apart from S.G. there is often Degrees Plato and sometimes ‘Potential Alcohol’ which is a fairly rough indicator of what percentage to expect. Degrees Plato expresses density as grams of sucrose per hundred grams of liquid- i.e. 10 degrees Plato would mean 10% sucrose by weight to 100% liquid. It’s a more common calibration amongst professionals and crops up only occasionally in homebrewing.

    Prior to the invention of the hydrometer a rather cumbersome method of weighing a barrel of wort and comparing it to the weight of a barrel of water was used. The wort barrel weighed more because of the dissolved sugar in it! Fortunately you will find your hydrometer a much easier option!

    Good Brewing!

    Copyright: Nick Birkby. Used with exclusive permission to Beerlab.

    Written by Info BeerLab — May 06, 2014

    Has my beer stopped fermenting?





    This is a common question that crops up amongst new brewers waiting expectantly on their first or second batch of beer. Fortunately it’s an easy question to answer -and a good opportunity to learn what happens during fermentation as well as a bit about using hydrometers. Read on!


    Firstly it’s a good idea to know what to expect of a fermenting batch of beer. Most of us know that there should be some vigorous bubbling from the airlock (much to the amusement of family members), and a thick head of yeast on top of the beer. This will slow down and eventually subside after a few days, signifying that the time for bottling is soon approaching.

    But what is really going on under that lid?


    To understand what’s really happening in the fermenter we need to understand the basics of what our yeast get up to. These friendly fungi are the ones actually making our beer for us at this point, so their habits and happiness is worth understanding.


    When pitched to the fermenter, the yeast first acclimatise to their new environment and begin to multiply many times over. The yeast use oxygen during this reproductive phase and this is the reason that brewers shake the fermenter vigorously for several minutes to oxygenate the wort before pitching the yeast. The yeast do not yet make any alcohol or carbon dioxide at this early stage -they are far too busy populating the contents of the fermenter! This quiet start is referred to as the lag phase and is where we expectantly wait for 12-24 hours for the yeast population to grow, and then begin on the important (and rowdy) task of producing alcohol!


    Well that’s pretty simple- but you guessed correctly that if the wort is not oxygenated the yeast won’t be able to multiply. This can happen if a brewer forgets to oxygenate or doesn’t shake the fermenter quite enough ( 4-5 minutes is best) . Another important factor is just how much yeast is pitched. A left over half sachet from a few months ago is not going to get the job done! There need to be enough healthy, viable yeast to get off to a strong start populating the wort. Too few simply cannot multiply enough times. So...always pitch a full rehydrated yeast sachet. The lag phase will be short and the yeast happy and plentiful!


    The next phase is the vigorous conversion of sugars to alcohol and carbon dioxide. The yeast have run out of oxygen and now turn to sugar for sustenance. They can survive without oxygen and enter a new phase known as ‘anaerobic’ (without oxygen). The yeast now produce alcohol, flavour compounds called esters and phenols, and work their way through the sugar. The carbon dioxide simultaneously produces a large head of yeasty froth on top of the beer and signifies the peak of fermentation. This busy and productive time is also commonly called ‘primary fermentation’ and is essentially when the magic happens and the young beer is created.


    Once the primary fermentation has begun in earnest there is not too much that can dissuade the yeast from quitting-excepting really cold conditions- below 16C say. As a general rule the cooler temperatures result in slower (and perhaps less energetic) primary fermentation times and warmer faster. Often this stage is over very quickly- two to three days is not uncommon with 4-7 being average. But it’s not quite over yet...


    The last phase of fermentation is where our original question usually arises. Is the beer almost ready? -What is it doing now?-Should I bottle it this weekend? I’m getting thirsty!

    After the initial crescendo of primary fermentation, the beer can look like it has completed its job. This is not at all true though. The young beer has now entered its last important phase known as secondary fermentation. At this point the yeast are still consuming any remaining sugars- though at a much slower rate – and also consuming by-products of the primary phase. The yeast is finishing the job thoroughly and also cleaning up after itself! With the sugar almost gone, the yeast finds and breaks down various other compounds which later affect the finished flavour of the beer. You could see it a gradual finishing or pre- maturation phase.


    Once the yeast has exhausted its supply of food it begins to go dormant. It clumps together and drops to the bottom of the fermenter, eventually leaving the beer clear(a process called flocculation) English brewers refer to this as the beer ’dropping bright’ .Depending on the yeast this can happen quite quickly or sometimes take a while.

    The fermentation is essentially now over, and the beer is beginning to mature. So is my beer ready? Typically, yes, but let’s look at some important time frames and scenarios. Being aware of variables is what is important now...


    Most advice to home brewers suggests a total fermentation time of 12-14 days. This is assuming a ‘textbook brew’ with plenty of healthy yeast and fermentation at a suitable temperature ( 17C-24C ). Generally things work out fine within this timeframe and temperature range. The beer is then bottled, undergoes carbonation from a small secondary fermentation (from added priming sugar) and then has a week or three to mature before drinking.


    Now that you have a general idea of what’s going on under the lid let’s quickly look at how a hydrometer can help us measure the yeast’s progress, and help calculate the alcohol content of our finished beer. A hydrometer is a useful floating measure that will sink lower or float higher depending on how much dissolved sugar is in our beer. Most brewers take a gravity reading just before the yeast is pitched, and then again before bottling. As the yeast consumes the sugar, the hydrometer readings will gradually drop (as the hydrometer floats lower). Generally, taking a reading during fermentation is quite unnecessary if things are progressing normally. Remember, frequently opening your fermenter exposes the contents to bacteria and wild yeast, though if you have a side tap this is a bit less of an issue. There is a good bit of common advice that if one takes a reading for a few consecutive days and gets the same results, the yeast has finished the work –though again this typically this isn’t necessary unless you really aren’t sure.


    Measuring the alcohol content is done by taking (and writing down!) a gravity reading just prior to fermentation called the Original Gravity (shortened to O.G.), and then, at the end of fermentation the Final Gravity (F.G.). The subtracted from the O.G. and multiplied by 0.129 to give the Alcohol by Volume (the same %ABV we see on our commercial beer and wine bottles). Here are three examples of some typical strengths of beer, beginning with an average strength.


    Average: O.G. 1.048     F.G. 1.011.         1.048-1.011=0.037             37 X 0.129=4.77% A.B.V.


    Light :       O.G. 1.034     F.G.1.008           1.034-1.008=0.026             26 X 0.129=3.35% A.B.V.


    Strong :   O.G.1.069       F.G.1.014           1.069-1.014=0.055             55 X 0.129=7.09% A.B.V


    In another post I will take a more detailed look at using a hydrometer, but that’s a useful start for now!


    To round up, let’s quickly look at where a fermentation cycle can go astray, take too long or just seem wrong – and why. By now you now have a pretty clear idea of the fermentation phases happening inside fermenter as well as some of the possible pitfalls. Here’s a set of easy ‘Best case’ versus ‘Concerned! ‘scenarios to help you!


    The lag phase: Best case scenario:

    A full sachet of rehydrated yeast s pitched and begins to ferment (bubbling airlock) after 6-12 hours (or even sooner). The temperature is within target range specified on sachet (or manufacturer’s website)The wort was vigorously shaken and splashed to aerate it thoroughly. A light froth begins to form on the beer.


    The lag phase. Concerned! :

    After 24 hours nothing is happening or there is only very occasional bubbling from the airlock.


    • Check that the airlock is properly secured- often a slight leak in the airlock’s grommet seal stops it from bubbling as the CO2 is escaping around it. 17C to 24C is your ballpark. A quick peak in the fermenter may reveal an actively fermenting beer!
    • Is the fermenter sitting in an icy winter garage or is the temperature really low? Keep the fermenter in a warm enough room. 17C to 24C is your ballpark. Did you aerate enough (or possibly forget)? If not, do so immediately- it should help get things going.
    • Under-pitching(not enough) yeast will also slow things down considerably. Consider pitching more yeast. Slow bubbling does mean something is happening – often it will simply get going properly in another few hours. If you have checked through the variables, grab a beer and don’t worry.


    Primary Fermentation: Best case scenario:

    A rocky head of yeast forms on the beer and the airlock is happily bubbling away. Regular bubbling slows right down after three to six days (sometimes sooner) . A foam line can be visible from the high ‘krausen’ on some fermenters. Remember: warmer temperatures result in faster fermentations than colder.


    Primary fermentation. Concerned!:


    Very slow or sluggish fermentation.

    • Cold temperatures are your main cause for concern here if the other factors like yeast and aeration have been checked. Move the fermenter to a warmer area.
    • Warm temperature and a low gravity beer can lead to very quick fermentations- as short as 2-3 days. Primary fermentation may have already taken place.


    Secondary fermentation. Best case scenario:


    The airlock slows down to a very occasional bubble. The surface of the beer clears with a few light patches of thin foam here and there. Many brewers use the airlock as an indicator at this point-once activity stops completely the beer is done. This works pretty well, just be aware that a very cold spell can also make your yeast go temporarily dormant!

    At this stage the beer begins to clear of yeast, and after a few days the yeast should have formed a thick visible layer at the bottom and the beer cleared. At this time you can bottle within a few days or let it mature for another week or so if you do not have time. Remember; two to three weeks are the best length of time to wait before bottling.


    Secondary fermentation. Concerned! :


    The beer smells ‘off’ or the airlock is persistently bubbling.


    • A bad smell (and there are many kinds!) or a visible growth on top of the beer means that wild yeast and/or bacteria have got in and wreaked havoc. Pay more attention to sanitizing. It’s not common, but it does sometimes happen-quite often more in summer or autumn when there is a lot of wild yeast floating around. A ‘green apple’ smell is normal for young beer, and a light sulphur smell is also known with some yeast strains.
    • A persistent fermentation can mean two things. Most probably the yeast is simply taking longer to get the job done or, less likely, wild yeast and bacteria have taken residence. Most likely it is the strain of yeast that is simply taking a little longer than usual. If in doubt have a sniff in the fermenter. It should smell initially of carbon dioxide followed by a clean beer/hoppy/slight green apple aroma. If in doubt, a gravity reading will help.


    With a little experience and the information here, you will soon always know when your beer is ready. And it’s a very satisfying thing to know too-good luck with your brews!


    This article is copyright and used with exclusive permission to Beerlab. Nick Birkby 2013

    Written by Info BeerLab — September 01, 2013

    Carbonating your beer

    A simple guide to carbonating your beer with granulated sugar using a priming solution. 

    Written by Lynnae Endersby — June 20, 2013

    BeerLab introduces Thomas Fawcett Malts

    When we started looking at another malting company to supply BeerLab with quality, hard to find malt varieties it did not take us long to decide on Thomas Fawcett and sons. Their rich history, the fact that they still do traditional floor malting and their outstanding reputation for quality made the decision a easy one (our fondness for English style beers also helped!). To our knowledge, this is the first major consignment of English malts to be made available to local home brewers.


    One of the owners of Thomas Fawcett (James Fawcett) personally assisted us with our first order (talk about a personal touch). We had to apply for importers codes, source freight and forwarding companies and learn the lingo along the way. After  tracking our malt on its 2 month long journey from the UK it finally arrives today, and we are very excited to introduce these new varieties - especially Maris Otter, a renowned English varietal.  Here is some history on our newest partner in brewing.




    The Fawcett family has been making malt in Castleford, West Yorkshire since the late 1780's. They still operate on their original site in Castleford, West Yorkshire where all their products are manufactured.

    Fawcett's supplies malts to brewers who produce Morland's Speckled Hen, Bass' Caffreys Irish Ale and the beers of the Black Sheep Brewery to mention a few.

    Fawcett's has kept abreast of technological progress in the malting industry without losing sight of traditional and proven methods. Today, Fawcett's remain as one of the few Maltsters still operating a floor maltings in conjunction with a saladin maltings and a state of the art automated germinating kilning vessel (GKV).




    The Company produces an extensive range of coloured malt products from the palest caramalts through the crystal colour range to the chocolate and black malts. The company operates roasting machines that roast between 0.5 tonne and one tonne of product at a time since they believe better results come from smaller batch sizes


    The Range of Fawcett's Malt available at BeerLab

    Maris Otter
    4.5 - 5.5 Main ingredient for all varieties of bitters, milds and stouts
    Caramalt 25 - 30 Lager flavour pale
    Pale Crystal 60 - 80 Lager - Pale Bitter (flavour and colour)
    Dark Crystal 200 - 400 Milds - Dark Bitters (strong reddish)
    Amber 90 - 110 Bitters - Pale Mild
    Brown 110 - 140 Milds and Darker Bitters
    Chocolate 940 - 1100 Stout and Dark Milds
    Wheat Malt 3.5 Head retention - dry biscuity flavour
    Oat Malt 4.0 Enhances body and flavour of Stouts, Porters and Winter Warmers
    Torrefied Wheat 3.5 Enhances head retention and produces a slight biscuity flavour



    Click on the link to see James Fawcett inspecting malted barley and their malt being used at Hawkshead brewery in the UK.




    Written by Lynnae Endersby — June 17, 2013

    Carbonation Chart



    Barley Wine                                          1.3 - 2.3
    Belgian Specialty     

    Dubbel                                                  1.9 - 2.4
    Trippel                                                  1.9 - 2.4
    Belgian Ale                                           1.9 - 2.5
    Belgian Strong Ale                               1.9 - 2.4
    White                                                     2.1 - 2.6
    Lambic Gueuze                                     3.0 - 4.5
    Lambic Fruit                                          2.6 - 4.5
    Flanders Brown                                    1.9 - 2.5
    English Bitter    
    English Ordinary                                   0.75 - 1.3
    English Special                                     0.75 - 1.3
    English Extra Special                            0.75 - 1.3
    Scottish Ale    
    Scottish Light                                        0.75 - 1.3   
    Scottish Heavy                                      0.75 - 1.3
    Scottish Export                                      0.75 - 1.3
    Pale Ale    
    Classic English Pale Ale                        1.5 - 2.3
    India Pale Ale                                        1.5 - 2.3
    American Style Pale Ale                        2.26 - 2.78
    English & Scottish Strong Ale    
    English Old Ale / Strong Ale                  1.5 - 2.3
    Strong Scotch Ale                                 1.5 - 2.3
    Brown Ale
    English Brown Ale                                1.5 - 2.3
    English Mild Ale                                    1.3 - 2.0
    American Brown Ale                             1.5 - 2.5
    Robust Porter                                        1.8 - 2.5
    Brown Porter                                         1.7 - 2.5
    Classic Dry Irish                                    1.6 - 2.0   
    Foreign Style                                         2.3 - 2.6
    Sweet Stout                                           2.0 - 2.4
    Imperial Stout                                       1.5 - 2.3


    Traditional German Dark                      2.2 to 2.7
    Helles Bock                                           2.16 to 2.73
    Doppelbock                                           2.26 to 2.62
    Eisbock                                                 2.37
    Bavarian Dark    
    Munich Dunkel                                      2.21 - 2.66
    Schwarzbier                                          2.2 - 2.6
    American Dark    

    American Dark                                       2.5 - 2.7
    Dortmund/Export                                    2.57
    Munich Helles    
    Munich Helles                                         2.26 - 2.68
    Classic Pilsener    
    German Pilsener                                    2.52
    Bohemian Pilsener                                 2.3 - 2.5
    American Light Lager    
    American Standard                                 2.57
    American Premium                                 2.57 - 2.73
    Dry                                                          2.6 - 2.7
    Vienna                                                     2.4 - 2.6   
    Oktoberfest/Marzen                                2.57 - 2.73
    Cream Ale    
    Cream Ale                                               2.6 - 2.7
    German Wheat Beer    
    Berliner Weisse                                       3.45
    German-style Weizen (Weissbier)          3.6 - 4.48
    German-style Dunkelweizen                   3.6 - 4.48
    German-style Weizenbock                      3.71 - 4.74

    Written by Lynnae Endersby — October 11, 2012

    Recipe of the month - Miami Weiss


    Recipe of the month - Miami Weiss

    Spring has sprung and its time to start brewing for summer. One of the easiest and rewarding beers to make must be a Weiss Beer. I always like to add some kind of fruit to my Weiss beers, this beer has the zest of one orange added for a sweet and citrusy aroma (If orange is not your thing you can simply omit the zest). 

    This beer is ready to drink as soon as its carbonated. It will peak at 1 to 2 months. Serve at 4oC

    Miami Weiss (All Grain)

    Batch Size: 20.0 L
    Efficiency: 70.0%

    • Original Gravity: 1.053  
    • Final Gravity: 1.013
    • Alcohol: 5.2%
    • Bitterness: 14.2
    • Boil duration: 90 minutes


    • 2.54 kg Wheat Malt - added during mash
    • 2.54 kg Pale Ale Malt - added during mash
    • 50.0 g Hallertauer Hersbrucker (2.28%) - added during boil, boiled 90.0 m
    • Zest from one orange - added the last 10 minutes of the boil
    • 1 Fermentis WB-06 Safbrew WB-06
    • 5 ml Irish Moss

    Heat 15.5 Liters of water to 73oC. Add water to (cold) mash tun. Add Grain and mix. Wait for mash temperature to settle at 66oC (you can add boiling water or some ice cubes to adjust the temperature if needed)  

    Mash for 60 minutes

    Heat 23 Liters of water to 77oC. Sparge the grain and drain wort into your brew pot

    Bring the wort to the boil and add the hops. Boil for 90 minutes

    15 minutes before the end of the boil

    - Put immersion chiller in your pot

    - Add Irish moss

    10 minutes before the end of the boil

    -Add the grated zest of one orange

    At the end of the boil cool down wort to 21oC and add to the fermenter. Pitch re hydrated yeast

    Ideal fermentation temperature 19 - 23oC

    Ferment for 2 weeks. Bottle with 180 g granulated sugar boiled in 200 ml water for 10 minutes & cooled.


    Miami Weiss (Partial/Mini Mash)

    You will need a 15 L pot

    Batch Size: 20.0 L
    Efficiency: 70.0%

    • Original Gravity: 1.048 
    • Final Gravity: 1.012
    • Alcohol: 4.69% 
    • Bitterness: 15.7 
    • Boil duration: 60 minutes


    • 1.2 kg Wheat Malt
    • 1.2 kg  Pale Ale Malt
    • 1.5 kg Unhopped Wheat Liquid Malt Extract- added during boil, boiled 60.0 m
    • 55.0 g Hallertauer Hersbrucker (2.28%) - added during boil, boiled 60.0 m
    • Zest from one orange - added the last 10 minutes of the boil 
    • 1 x Fermentis WB-06 Safbrew WB-06
    • 5 ml Irish Moss

    Add crushed grain to a grain bag. Heat 6 L of water to 73 °C and mash grains at 66°C  for 90 minutes. (stir the grain in the grain bag well)

    Heat 6L of sparge water to 75°C

    Remove grain bag from grain water and  rinse with the heated sparge water. Bring wort to the boil, remove pot from the stove and add Liquid malt extract and hops. Boil wort for 60 minutes.

    15 minutes before the end of the boil

    -Add Irish moss

    10 minutes before the end of the boil

    -Add the grated zest of one orange

    At the end of the boil remove pot from the stove and cool. Strain the cooled wort into the primary fermenter and add top up the fermenter obtain 20 L. When wort temperature is under to 21oC pitch your re hydrated yeast

    Ideal fermentation temperature 19 - 23oC

    Ferment for 2 weeks. Bottle with 180 g granulated sugar boiled in 200 ml water for 10 minutes & cooled.

    Written by Lynnae Endersby — September 06, 2012

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