Brew it yourself No6

This month, Charlotte Cook explains how to read the runes and omens that make up a standard home-brew beer recipe.

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Charlotte Cook

Saturday 17 October 2026

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This article is from

South Africa

issue 136

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A crucial part of getting a homebrew from grain to glass is deciding on a recipe. In this instalment we are going to look at how to read and prepare a homebrew recipe, from picking the right one to understanding the acronyms.

THE HEADLINES

The first things that you’ll usually see are the beer name and style; if you’re new to brewing, a multi-malt imperial stout might not be the best jumping-off point, but most recipe titles are fairly on the nose, meaning you can find one that suits your needs without too much trouble.

One of the most fundamental decisions you’ll make is how much beer you’re brewing, and it’s often not as straightforward as you might think. Usually the brew length (the volume of wort produced during a brew) is stated along with the recipe title, and it’s important to check and stick to this. A lot of novice brewers get caught out by the fact that a recipe designed for 20 litres will not make a delicious 30-litre batch if you simply increase every ingredient by 50%. While you can scale your recipes up or down as needed, hop bitterness for example doesn’t scale linearly, so use a specialised brewers’ calculator to make the adjustments for you – www.brewersfriend.com offers a popular free option.

Next you’ll usually see the target ABV%, which is pretty familiar to most beer fans. Where your ABV actually ends up can be affected by things like temperature and the amount of water used in the process, but if you follow the recipe, it should be largely correct. You’ll also want to note the IBU (International Bittering Units) which uses a 1-100 (or thereabouts) scale to measure bitterness in beer. A light lager might have 15 IBUs and a deeply bitter west coast IPA might have 70+.

THE FINE TUNING

Now we start to look at things a new homebrewer might not have encountered. Most recipes will have both an Original Gravity (OG) and a Final Gravity (FG) number. These relate to the density of the liquid, which indicates roughly how much sugar is held in solution before (OG) and after (FG) fermentation. Taking gravity readings before and after fermentation is important, because the difference tells us how much of that sugar has been converted to alcohol, and therefore allows us to calculate ABV.

The unit we use to describe these values is called Specific Gravity (SG) or sometimes Plato (°P), and the scale runs from 1.000 which is the gravity of water (no sugar) upwards. Over the course of fermentation you’ll see the SG drop as sugars in the wort you’ve created are converted into ethanol and carbon dioxide.

The higher the OG the stronger the beer, as there’s generally more sugar available for the yeast to metabolise, and more alcohol is produced. The higher the FG, generally, the sweeter the beer. Some beers such as light lagers might have an FG of 1.008 whereas a sweeter stout could be north of 1.020.

Instead of an FG, some recipes will have a ‘Target Attenuation’ figure, which lets you know the percentage of sugars in the wort that should ferment in order for the correct amount of alcohol and residual sugars to be left behind (attenuation). A beer can under-attenuate if the mash was too hot or thick, or over-attenuate if it was too cool or thin.

The colour of the beer will also be given, either in European Brewing Congress (EBC) or Standard Reference Method (SRM) units. The higher the number the darker the beer, but to check simply pull up an online reference sheet with approximate colours against which you can compare your wort.

GETTING SET UP

To ensure you get the thickness correct, the recipe will also list both the Mash Liquor Volume and the Liquor/Mash Ratio (or Liquor-to-Grist Ratio). The liquor volume is simply the amount of water that you will use to mash in.

The liquor-to-grist ratio is the amount of grain compared to the amount of water used during mashing in. It tends to hover around the 2.7-3L of water to one kilo of malt and will be expressed like ‘2.7 : 1’. This metric is important, as the thickness of the mash affects how enzymes – which break down starches into sugars – react, so along with temperature these need to be carefully followed.

Mash temperature will also be listed, and will generally sit somewhere between 64°C and 68°C. How you achieve this will depend on your set up, but remember that the mashing liquor will generally be hotter than your target mash temperature as the malt will take the temperature down. This is one of the most important things to get right, but you can make some adjustments once mashed in. The mash rest time isn’t always listed, but 60 minutes is standard.

INGREDIENTS

The recipe will list the ingredients separated into hops, malt, yeast and any other ingredients, as well as when to add them. For most malts, you will mix these together when mashing in on a single-infusion system. Some fancier stepped mashes, which you can perform if your kit allows you to adjust the temperature during the mashing process, will explain when and at what temperature to add different grains.

One thing to keep in mind is that the recipe might have the brand name of a particular malt on it, and if you don’t have that particular brand, you’ll need to do a bit of digging to find a replacement. Luckily most maltsters do variations around the same style of malts (with the exception of some German speciality malts, for which you will have to source the correct brand). If you get a recipe that specifies, for example, a specific brand of crystal malt, simply have a look at the malt available from your homebrew shop or website, and there will be something roughly analogous. Your supplier can also advise if you’re unsure, but there’s no reason to search around for specific malts when something that’s just as good will be easier to source.

Yeast can also be changed around somewhat. Your recipe will tell you how much of a certain type of yeast to add, and at what temperature to ferment it. Most yeast labs will make variations on most beer styles, and while some companies, such as Fermentis, have the rights to use certain strains from celebrated breweries, you don’t have to use these. For example, if a recipe asks you to use the Verdant yeast, you can just as easily use London Fog. Some recipes will be sponsored by manufacturers, but it’s often worth shopping around to find the right malt or yeast to fit your budget and requirements.

Hops are a little less flexible in most recipes. Since certain hops are more suited to certain beer styles than others, it can be hard to substitute them without significantly altering the final product. If you swapped out English hops for New Zealand Motueka or American Sabro when making a Best Bitter, you’d end up with a completely different beer.

One thing to pay attention to with hops is the ‘Alpha Acid %’, which will be listed beside the hop variety on the recipe. Alpha Acids are used to bitter beer, and the first or ‘start of boil’ hops will give the beer its bitterness. The more Alpha Acid added to the wort, the more bitter it will be, provided the acids have time and adequate heat to isomerise. If, gram-for-gram, you were to swap a 7% Alpha hop for a 14% variety at the start of the boil, you’d end up with a beer that’s much more bitter than intended. However, there are online calculators to adjust the hop volumes if needed.

Your recipe may well include multiple hop types, to be introduced in different quantities, at different points in the boil. Common intervals are at 30 or 45 minutes, or at ‘flame out’ which is when the heat source is turned off. Some more advanced recipes might call for a ‘whirlpool addition’, which involves adding hops once cooling has begun. These additions will allow you to add more aroma to the beer, and can be added at flame out if your set up doesn’t include a whirlpool, or have accurate temperature controls.

Getting your head around what all of these acronyms and figures mean, and why they are important, will help the brew day go smoothly. If this still feels somewhat intimidating, then buying a pre-prepared recipe kit from somewhere like Malt Miller and following the instructions can help build up your confidence and give you experience before trying to follow a recipe completely from scratch.

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