Crushed grain can still convert after 1 yr - Experimental proof

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

pjj2ba

Look under the recliner
HBT Supporter
Joined
Jul 25, 2006
Messages
3,372
Reaction score
235
Location
State College
Let's try this again, I think my title in my other thread had people thinking, "man, yet another crushed grain thread".:mad: No, this is the RESULTS of the experiment.

I helped my wife set up and run a new lab for her class (Intro. Plant Biology) that primarily was to show the students starch conversion. She used to have them do this complicated (but classic) barley half-seed experiment that looked at the role of hormones, the embryo, and a bunch of other things involved in seed germination/starch degradation. It was a pain, and I usually got roped into making hundreds of petri plates with different additons to the starch containing media. Last year we did a demo of mashing, this year we had the students do the new experiment.

Basically we have the students do a really mini-mash (1 gm in 10 ml of water), and then use iodine to monitor starch conversion. We had them compare 6-row, 2-row, and Vienna malt. We also had some leftover malts (6 & 2-row) from last year, so I thought, hey, what a great chance to check for crushed malt longevity! The malt from last fall was just crushed and then sealed in a ziploc bag and kept at ~ 70 F for one year. The husks cause some problems so this year I double milled the grains and then removed as much of the husks as possible giving me a malt "flour". I then took this malt and ran it through a coffee grinding to make it really fine. The year old malt (and it's husks) was also ground in a similar manner. Therefore the year-old malt will have less endosperm, gram for gram compared to the fresh stuff.

We've been busy so we hadn't worked all of the bugs out ahead of time so we thought we'd have the students help to figure out the best protocols. That wasn't working so well, so I set up some reactions this morning. I did times 0, 10 min, and 20 min. (plus 35 min. for two of them)

Results:
starch-assay-1.jpg
starch-assay-2.jpg


As expected 6-row was the fastest. 2-row and Vienna were close behind. And the biggies, both the year old crushed 2 and 6 row were able to convert. The old 6-row was fully converted within 35 min. I suspect if I waited another 10-15 min, the old 2-row would have been fully converted

I think the key was that the crushed malt was stored in air-tight bags. So, as long as crushed grain is stored properly, it can retain a good chunk of it's enzymatic activity.


I post the results again next year. I'll save some of the finely ground malt powder I just made and check it again next fall. Maybe some 2 year old then too. I'll also intentionally store some in a poorly sealed container.
 
I still wouldn't want to use it, but it's an interesting experiment. :mug:

I would be hesitant to use it myself. While it can still convert, that just gives one sugars to ferment. It doesn't address whether any of the flavor components held up to. - think stale cracker.

But if you are on a budget, or just Jonesing to brew and it's all you got. It probably won't make a beer a great beer, but for those not fussy, it would be beer.
 
pjj2ba - Thanks, I learned something today that I would never have tried myself. Seriously, that was great.
 
Back
Top