whole grain vs. direct sunlight, who wins?

question...so we've got this new store in town that just started to carry bulk grains...awesome, right? couldn't be happier to have a LHBS that sells grain by the oz, or 50 lb bag if needed. no more shipping and handling charges. but here's the deal....they probably have 30+ varieties of grain and they're stored in those clear plastic cereal/coffee bean dispensers you see at some grocery stores (you know, where you pull the little lever and the stuff pours out the bottom). thing is, the grain station sits up next to a huge plate glass window with southern exposure...for most of the year that equals tons of direct sunlight all day. i'm fairly new to AG brewing...but i got to imagine that ain't good for the grain? we're not a big city so i don't imagine they move too much product....just wondering, how much UV exposure will turn grain evil? is it worth letting the manager know? thanks in advance!

 

That's a good question. I'm really surprised that anyone selling a food product would put it into the light like that.

The good news is that plastic does not pass UV at all. Still, a little bit over a long time could have some effect. Or maybe not.

I would think, if anything, the exposure would act to dry it more, which would prolong it's life. Hard to say what the affect on the enzymes would be. It's possible they denature more quickly, but that's just a possibility - I've no idea really. Just tossing out some food for thought.

 

huh, i didn't realize plastic didn't pass UV...that's good to know. the bins probably only hold 20 lbs each. so i'd imagine the more popular grains get moved through pretty quick, thus limiting their exposure to direct sunlight. i picked up some smoked malt today and kinda started to wonder how long it might have been there...

 

I'm not an expert on the topic by any means, but AFAIK there isn't really any negative effect caused by grain being exposed to sunlight. Hops would be a different story. However, I would be more concerned with the grains not really being in a well-sealed container that they would absorb more moisture than normal, and stale faster or possibly even mold. Malted grain should have a residual moisture somewhere in the 4% range, which is well below the comfortable humidity range for people. If you pick up the grain and it's soft instead of crisp or crunchy it hasn't been sealed well and has absorbed moisture.

 

Sounds like a weevil farm in the making!

 

You got that right.

 

If their turnover is good, it won't matter much.

Ask the store owner about it. Good conversation starter, at least.

 

I wouldn't be as worried about the UV as much as the heat.

 

I don't think it would hurt. Very little UV light can get through even clear glass.

 

Maybe the windows were fused silica. That's what I use for UV windows.