Brewers Insights – How to read a beer recipe and calculate liquor volumes

Hello, this week we have had many questions form brewers who are making

recipe kits asking about various different parts of the method that appear to

have been missed out, we are going to unlock the answers so you can easily

brew any recipe knowing just the brew length and ingredients listed.

let’s look at a recipe, know I have chosen the Son of Punkie recipe

as although it’s not complicated it is slightly different from the norm in the hop

timings.

SON OF PUNKIE

There is little point in us adding exact liquor volumes, strike temperatures and

the like as we all have different brewing systems, what will be right for

someone brewing on a Grainfather will not be right for a brew on a three

vessel brewhouse. Giving instructions for these variables is misleading which

is why we don’t do it.

The first thing to look at is the malt bill, on this recipe it is easy, just 5kg of

Maris Otter. It is the weight of the grain bill that is important, as this gives us

our calculation for our mash liquor. As a rule of thumb you will use 2.5 litres of

mash liquor to each kilo of grain. So this gives a mash liquor volume of 12.5

litres.

The instructions say to mash at 66c, hitting somewhere close to this is

important as adjusting either up or down is a bit of a pain. Getting this strike

liquor temperature right is down to trial and error on the brewers part, it’s

about getting to know your system. Type of mash tun here is very important,

plastic tends to pull less heat away from strike water than stainless.

Also the temperature of the grain, perhaps this is likely to be cooler in winter

than summer. My advice is to keep the grain at room temperature over night

before brew day, there will be less variation that way.

Pre heat your mashtun, add a kettle of two of boiling water, pop the lid on and

leave for a good few minutes, before draining. It doesn’t take many brews to

get this temperature nailed but a good starting point is 74c. So we would add

12.5 litres of mash liquor to the 5kg of Maris Otter and this will get us close to

the 66c required.

The mash time is the required rest from adding you liquor to time of draining

or sparging the mash tun, in this case 90 minutes. You can see on this recipe

that it has a mash out temperature and time. If you are brewing on a single

vessel system such as a Grainfather or Brewtools then this is easily done on

the control pannel, if you have a standard mash tun ignore this step.

Next we need to know how much sparge liquor. A couple of points here, the

grain absorbs mash liquor and it’s unlikely that your mash tun is 100%

draining. This is called your dead space, all vessels will likely have it to some

extent and it is best to measure before you start, these volumes can than be

added.

At this point it is best to work backwards, we know the final batch size into the

fermenter is 19 litres, how do we work out the sparge liquor, the amount of

boil off etc. We have calculators on the site that are designed exactly for the

purpose. They allow you to punch in the information that you know, and the

calculators have an educated guess at the values you don’t, and come up

with the results that you require.

You can see here that we have to sparge with about 19 litres to give us a pre

boil volume of about 25 litres. The 6 litres of wort will be lost to evaporation,

kettle dead space and those thirsty hops, these soak up about a litre of wort

per 100g.

Finally, lets look at the hop timings. In a beer recipe hops are timed from the

end of the boil. Here we have Apollo as the first edition at 12 minutes before

the end, it is a 60 minute total boil, add the Apollo hops at when the wort has

been boiling for 48 minutes. You can see that there are others at 5 minutes

before the end.

Take note of hop additions at zero or flame out or steep hops. These are to be

added once the boil has finished and generally steeped in the wort for about

20 minutes.

There is also a dry hop edition, approaches to dry hopping are changing very

rapidly, I would urge brewers to experiment with different methods, however,

traditionally they’re added when fermentation is almost over and in a recipe,

measured in days contact with the wort.

Using this information will allow you to brew any beer recipe as long as you

know the batch size and ingredients.