Calculating a grain bill from percentages

[JamesF]

I was trying to work this out last night...

Say I have a recipe with a target OG of 1045 where the malts are listed as, say, 80% pale, 15% crystal, 5% chocolate. For a given wort volume (say 25 litres for the sake of argument), how do I then calculate the weight of each malt required?

I assume I need to know the potential fermentable sugars extracted from each malt during mashing and the brewhouse efficiency after which point it's relatively simple maths, but the "usual suspects" for supplying malts don't seem to provide much information by way of the first. Do people use some sort of average figure for each type of malt?

James

[guypettigrew]

As a starting point a beer of 1.045 OG will need about 4.5 kilos of grain.

You can then use Graham Wheeler's beer engine to work out the fine details. You'll find the GW beer engine on here at: JBK Links>brewing calculators>Graham Wheeler's original beer engine calculator.

JBK links is at the top of the page, by the way.

Have fun!

Guy

[JonB]

+1 for beer engine (other software such as Brewfather is available)

It also depends on your system's mash and brewhouse efficiencies as well, these can be worked out by plugging in a recipe you've brewed previously into said software and adjusting the efficiencies until the numbers match your actual OG and volume. Ideally for Mash efficiency you need a Pre-boil gravity and volume but you can probably take a rough punt using Brewhouse efficiency to get you in the right ball-park...

(if you have no data to use, then try the defaults and make a note of what you actually get out and adjust for next time)


With Beer Engine you can put in the manufacturer's data (LDK, moisture content, etc.) in the grain editor and it will do the maths for you. Brewfather has most commercially available malts saved into it with typical data values so you can skip this step, but I've always used Beer Engine and trust the values that come out of it (Brewfather can be radically different in terms of IBUs, extract, etc.). The colour indicator on Beer Engine however is not especially accurate so I tend to ignore that value...

[JamesF]

Looks like I might have to "borrow" my daughter's Windows laptop then

James

[guypettigrew]

Looks like I might have to "borrow" my daughter's Windows laptop then

James

Why?? If you can access this site then you can access Beer Engine.

Confused!!

Guy

[JamesF]

Perhaps I've misunderstood something. In your first post you explained how to find the BeerEngine link which, assuming I have the right one appears to be a .exe file and therefore will only run on Windows? Or am I confused?

James

[themadhippy]

and therefore will only run on Windows? Or am I confused?

Depends,you can run some .exe files on linux, macs and supposedly also on android,you just need some wine https://www.winehq.org/

[JamesF]

Aha! I have just discovered that https://github.com/jimbob88/wheelers-wort-works is an update of BeerEngine written in Python that should run on Windows, MacOS or Linux. I shall download that and give it a whirl.

James

[guypettigrew]

Best of luck! I hadn't realised GW's Beer Engine would only run on Windows.

I also hadn't realised some people don't use Windows! My IT knowledge is minimal.

Guy

[JamesF]

No problem. Your answer did at least push me down a path I wasn't even aware existed.

James

[IPA]

With Beer engine just enter volume and gravity. Add the ingredients as percentages and hey presto it will give you the weights as well.