I had a friend ask me about this last night and I cant remember why its not good to store grains that you have already milled. Im kind of interested in ordering a god bit of grain in bulk and having it milled already since I dont have a mill right now. What are some of the down sides of keeping milled grains around? Should you keep it in a vacuum sealed bags? Should you keep it in the fridge if its a small amount? Thanks guys!
The simple answer is it gets stale (oxidizes). But if you must do it, vacuum sealing should help. I've never had the need to store milled grain though.
This is from a Briess Spec Sheet: STORAGE AND SHELF LIFE Store in a temperate, low humidity, pest free environment at temperatures of <90 ºF. Improperly stored malts are prone to loss of freshness and flavor. Whole kernel diastatic and preground malts are best when used within 6 months from date of manufacture. Whole kernel roasted malts may begin experiencing a slight flavor loss after 18 months.
I can partially back up that claim with personal experience, I have gone up to 3 months with crushed grains before using with no ill effects
Permit me to suggest a Bitter Ale using Wyeast 1469. I also enjoy Maris Otter in my Oatmeal Stouts. Cheers!
So Briess is claiming that 'whole kernel' (unmilled) diastatic malts and 'preground' (milled) malts have the same shelf life? IMO that's enough to doubt anything else subjective they say.
If I bought bulk grain, I would buy it uncrushed and crush grains as I go. Currently, I do not do things this way because I do not have a crusher. Instead, I buy crushed grains that I hope to use in a week or two. This is especially true for basemalts. I might have fractional pounds of specialty malts that sit around for several months. There have been occasions where my brewing schedule got interrupted and I brewed a batch with crushed grains that were months old. The longest was a 6 month old grist- I do not recall the style, but I recall nothing unsual about the beer. As Jack noted, Briess suggests 6 months on their website. I believe I have heard other sources suggest less time than that. One variable that is out of your control and likely remains an unknown is how long since the grain left the maltster. Therefore, you might plan to err on the side of caution, as I do, but recognize that there may be times where you have to push the envelope and not sweat it too much (+10 points for ending a post with a mixed metaphor).
"The longest was a 6 month old grist- I do not recall the style, but I recall nothing unsual about the beer." Sounds like confirmation to me! Cheers to pweis909!!
I brewed a Bud clone that won our club style challenge (Standard American Lager) with pils malt that was milled 8 months previously, and the Green Mtn. Mashers are no slacker club (Sean Lawson was a member till he went pro). I am exceptionally fortunate to have a cold, dry cellar where I store malt double bagged and placed inside a trash can with a good seal. If you live in e.g. TX or LA your shelf life is probably measured in weeks rather than months, at best. If you live in Antarctica, it might keep longer than you. YMMV.
I don't think I've ever seen a thread on here that started with, "I shouldn't have used those old grains." While I don't think I'd use old grains for a competition style beer, I've yet to have a bad beer out of grains that are 18 months old.
Keeping milled grains around means you're not brewing often enough which counts as a sad. Whole grains are not bone-dry. Vacuum storage in cooler conditions could cause condensation. Condensation creates favorable conditions for mold. Short answer: no. Longer answer: refrigeratorating ==> condensation. Condensation ==> mold.
