Hi all - I excitedly tore into a sack new sack of Crisp Maris Otter to dump into my airtight buckets for long term storage. As I was pouring them I noticed some thick clumps pouring out with the grain. I inspected further and they were green/yellow moldy clumps of grain - about 7 of them - golf ball size or smaller. I sifted them out and have the rest of the grain stored in my buckets. Should I be trashing this grain? The rest of the grain looked perfectly fine. I have never had this happen so I wanted to see if I should scrap it all and buy a new sack or not. Thanks!
Second on dumping it. Even if you pulled the clumps, there will likely be mold in the non-clumped stuff that will in the best case give a nasty flavor to the beer. I would contact your supplier and see about a refund if you can.
Second on dumping. Mold spores can spread everywhere. If it is contaminated you don’t want that going through your mill. I suspect that it also has a different smell to it. How long did you have the sack before opening it?
Malt and grain are covered with all sorts of bacteria and mold. It’s foolish to think that the problem is fixed by throwing out that sack and buying another.
I’m guessing that the sack had a few drops of water fall on it and that’s all it takes to enable organisms to take off and grow. I would remove those clumps and use as normal. However, I’d make sure that the malt is still crisp and flavorful. If the grains have become soggy or stale tasting, then it’s ruined and out it goes.
My suggestion to toss was because visibly moldy grain is out of the ordinary, and can have a pretty pervasive flavor and aroma (having grown up on a farm that raised and stored various grains, I still have an aversion to the possibility of mold; that stuff smells pretty foul!).