BJCP CLASS – we were given a choice of presentation topics, and I chose Malt. Turns out Malt is one of the very first presentations, so I’ve been scrambling through a very busy week (end of fiscal quarter at work, Baronial At-Home on Wednesday at my house) to get something ready for class tomorrow. Yoiks.Our instructor, Les White, president of the Free State Brewers Guild Club and BJCP National judge, sent me some more background information to use (I have since posted the basic malt info and copies of the presentations separately – I even talk about how to make your malt). This info is about just how much “juice”, how much diastatic power different grains have – which in turn tells us how much they’ll ferment for us. It’s been really helpful, and I rather think we should all have the list of potential extract values of grains and adjuncts. I asked if I could post the materials he sent here, and he sent back proper attribution info, so I take that as a yes.
(Postscript: I’ve posted my own presentation as linked above. You know me, I love my history, so I’ll slip in some pics of five -thousand-year-old germination pools, and that nifty malting floor in the Nottingham caves. Just so you know.)
Malting is a particular process where you germinate grain then dry it, remove all the germination sprouts, and roast it to obtain particular flavors and color. The process makes starch, protein, and enzymes available that are advantageous to the fermentation process (yeast likes ’em and does nice things with them). Great, except then you have various grains with various amounts of protein and starch and enzymes available depending on their nature and how they’ve been processed. How do you figure out how to balance the load so you get wort that the yeast will make the most of, and that will come out tasting like you want it to?
So here’s a list of the potential extract values of grains and adjuncts that I think every brewer who’s ready to calculate gravities should have. This comes by way of Beersmith. By grains, they seem to mostly mean malt. An adjunct is any fermentable that isn’t a malt – so, corn, molasses, honey, unmalted oats, sorghum, raw wheat, rice or rice grits, stuff like that.
Why do I like this list? I’ve had a couple of batches of all-grain beer where we just didn’t get much out of the grain – even one batch I made with Misha Suggs, who knows a whole lot about beer and is a very consistent brewer. It’s time for me to start paying attention to what I should be getting compared to what I do get out of my grain!
There is an excellent bit of calculation at the end of this document that doesn’t copy into this post very well. If you download the document from the link, you’ll see it just fine, but for those of you using this page to see the list, here you are:
Formula for calculating extraction from grains:
(# of grain x potential extraction / @ of gallons) x efficiency percentage
2-row malt 6# 6×34=210
Vienna malt 8 oz .5 x 32 = 16
Caramel 10 malt 8 oz .5 x 24 = 12
Total = 238/5 gallons = 47.5 x .75 = 35.62
So, at 75% efficiency, expect an original gravity of 1.035-1.036 in 5 gallons of wort.
And here is the text, in case this format is easier for you to access:
Potential Extracts of Grains and Adjuncts
Potential extract indicates the theoretical maximum amount of extract available. The actual extract obtained in a homebrew setting will depend on mash efficiency, and will typically range between 60 and 80% of the potential extract, depending on the procedures used.