Brewhouse efficiency is arguably the #1 metric of brewhouse performance. It’s a true reflection of process control from malt intake to casting out. There is also a direct cost saving and carbon emission saving impact of having a strong brewhouse efficiency explains Chris Lewington, the founder of Brew Resourceful.
In the essence of efficiency lets get straight into it. You ready?
Brewhouse Efficiency (%) = (Total Extract from Brewhouse/Extract Received in malt) * 100
Results can range from 60-100+% depending on entrenched reasons like:
- Mash & Separation Technology
- Style of beer
- ‘Quality’ of malt
But there are many many more actionable reasons such as
- pH control
- Milling process
- Mashing process
- Separation process
- Time
- Temperatures
- Operation standardisation
As with all brewing there are many ways in which to generate a result. In this article I will be discussing just one way of measuring your brewhouse efficiency.
The purpose of this article is to give you a usable Brewhouse Efficiency Calculator and enough understanding to use it. If you already measure it, this article could help you better understand how it is calculated and offer good tips to get more consistent, reliable and accurate results.
Malt Certificate of Analysis (COA)
Every batch of malt should come with a Certificate of Analysis (COA) (Preferably electronically). Either way you will receive one looking like this one supplied by Paul’s Malt for their Pale Malt called Pale Whale.
There are some really good materials available on how to understand the full COA. This post will not be one of them. But they will be supplied at the end for further understanding.
There are three popular sets of standards used to ensure malt analysis is consistent. They are:
- IOB – Institute of Brewing – United Kingdom
- EBC – European Brewing Chemists – Europe
- ASBC – American Society of Brewing Chemists – United States
Pauls Malt are a UK malting company and therefore use the IOB set of standards.
The IOB analysis craft brewers are looking for in relation to extract is the ‘IOB Extract 0.7mm’ which refers to the ‘grind size’ used to break up the malt for the test. Unless using a hammer mill your milled malt will be closer to that of the 0.7mm than that of the 0.2mm you can also see on the COA.
“Wow. Interesting. So I am not using all UK malt and have a % next to my extract value?” I hear you ask…
In the calculator provided it can receive either IOB, EBC and ASBC extract values. (although no difference in calculation is made between EBC and ASBC)
So when you come to use the calculator provided later on you select % and input the data there. Easy.
Dry vs as-is basis
You will see one or both on your COA. Dry basis means the malt sample used has been dried prior to testing.
But for the purpose of Brew House Efficiency we are only concerned with ‘as-is’ basis because this is what best represents the malt we have in the brewery.
“Oh crumbs, my COA only has ‘dry basis'”
Fear not. Its quick and easy to get the as-is extract we need.
as-is = ‘dry basis value’ * (1-‘moisture content %’)
Now of course you will need the exact quantity of each of the malts you have used in this batch.
Wort Gravity
A Few points to keep in mind
- Plato vs Specific Gravity. An actual personal favourite topic of mine. I am in team plato. HMU if you wanna know why.
- If you are adding water at any stage this will not affect your brewhouse efficiency as dilution of gravity is directly proportional to the additional volume.
(AS LONG as you are not using a gravity reading pre-dilution and a reading of volume post dilution. But no one is that sinister, right?)
- Yeast should not be included in the gravity/volume therefore gravity sample should be taken prior to yeast and volume recorded prior too.
- Pick a sample location and stick to it. Sample locations should reflect the intention of the result. In this case, we want the location that represents the final stage of wort during or prior to filling the fermenter so we can get an honest reflection of brewhouse performance. (The wort line is a great sample location)
If this is not possible then try to analyse your process and find the most representative of the final stage of wort where it is the most homogenous
Consistency is key if you want to learn off your results.
Wort Quantity
So this is pretty simple. How much wort (in hectolitres) has been collected into the fermenter. But the question is how to measure it. If you blessed with a flow meter to count the quantity of wort for you.
Excellent. Just remember consistency of when and how you record the wort quantity is equally important as the accuracy of the flow meter.
Consistency is key if you want to learn off your results. If you do not have a flow meter. Whilst inconvenient, there are many, many ways you can count your wort quantity.
“Can I finally use the calculator now?!” I hear you ask. Well yes, yes it’s now time for action. With your COA’s, malt quantities, wort gravity and wort quantity in hand. Plug the numbers in here and see what you get
Once you have a result, come back to find out what to do with it
Happy with your result?
Congratulations! Would you like to compare it a moving industry standard and also with breweries of a similar size? You can check that, here. If not, then get in touch!
Chris Lewington has been working for over a decade in the brewing departments of some of the industries most exciting and respected breweries. Managing breweries ranging from 2,000hl p/a to 250,000hl p/a his’range of experience and knowledge in craft brewing is unique. His new venture Brew Resourceful looks to utilise that experience and knowledge to make the brewing industry more resourceful, increasing breweries profitability and reducing carbon emissions with process based solutions. His long held belief of a better economic system means Brew Resourceful is a social enterprise reinvesting profits back to the brewing community.
