A few months ago, a friend gave me a ten pound sack of pilsner malt; it was a sample bag from a local malting house.
Lately, I’ve had problem with grain bugs… big problems. When I thought I was beating it, another wave of bugs would be found in my brewing pantry. Yesterday, I cut open this sack of pils and found it infested with grain bugs (and some mold).
Can grain bugs get in an out of a closed sack of grain?
If it was a plastic hot sealed bag then my vote is you got the bugs with the grain.
If it’s a Kraft Paper bag sewed shut then I suspect they probably got in from your local colony.
The bugs might gross you out but really, they’re not a problem from a safety standpoint. The mold is potentially a huge problem, however. Mold on dry grain could be a strain of Aspergillus, some of which produce aflatoxin, which is a strong carcinogen. I’d throw the whole bag out if I were you.
The bag was a ten pound version of the same bags that Rahr Malt or Best Malt uses with their 55 pound bags: A woven nylon bag on the outside and a ‘solid’ transparent plastic bag on the inside. You open it up by pulling on the string on top.
I’ve had very minor grain bug problems in the past, but the problem got very big in recent months. I used Combat roach bait in my pantry, which killed a lot, but not all of them. After opening the bag, and discovering them, I quickly got rid of the grain.
The bug problem is already lessened.
RC, the bugs–given time–will eat enough of your grain to ruin your efficiency. And my efficiency has dropped at least 5%.
Just a use more if efficiency is down. If you put the grain bag in a plastic bucket or garbage can and direct your blow off tube into the bucket, the CO2 will suffocate the weevils and rid your infestation.
Think of the bugs as a free yeast nutrient!
Doesn’t help now any I feel the others have you covered but watch homebrew finds for Vittle Vault sales… or just grab one off Amazon. It’ll help to prevent le bugs in the future. I have like 5 of them.
My brewing pantry is very tight. I might be able to get two in there.
What I’m doing, now, is I put all the grain in ziplock bags; I can get 2.5 gallon-size bags at the supermarket. Using these make it easier to store.
I should look for bigger bags… I use 2 each for Pilsner and Pale Ale malt and then I use 1 gallon bags for my miscellaneous box… or sandwich bags depending on what I have to maximize space.
I order three batches worth of grain at one time (to get free shipping from MoreBeer). The grains are delivered in heat sealed plastic bags.
I separate the order into batches and store them in plastic buckets with gamma lids. When I’m ready to brew that batch I grab the bucket and go.
Any leftover (partial pounds) of grain are weighed, marked, vacuum sealed, and stored in a cooler (which was my first MLT).
The bugs are a bummer but still ok to brew with. The mold can cause major problems including gushing and possibly mycotoxins
I know I probably mentioned this but a LHBS shop was infested with bugs. The resourceful owner told everyone that the grain was something like 25¢ a pound for anyone willing to buy it. I went and picked up 20 pounds of pilsner and thought it was clean. Eventually I noticed bugs (specifically, grain beetles… very small and dark) but I brewed with it anyway. I kept that bag in the garage so the bugs wouldn’t get into the rest of my grain and I used it as quickly as possible. The beers were good but the risk of having those bugs invade everything else taught me a lesson. Never again.
I worked part time at a local hb supply/bottle shop that went under. Thus I brought home most of the store inventory. One bag of maris otter is really heavily infested. Most of the rest is in buckets they haven’t found a way into so far.
You might still be able to brew with them as others have said but would you want to?
There are more than just the bugs themselves in your grain. Bugs defecate and their poop is called “frass”. Like all critters their lifespan comes to an end meaning you have bug carcasses in your grain as well. Probably a lot of them since your second infestation is likely the offspring of the now dead first generation(s). So when you raise a glass of that beer try not to think about all the bug shit and insect cadavers that went into it.
As mentioned above, I keep all of my grain in sealed plastic containers or mason jars. Vittles Vaults for the 55 lb. sacks, smaller containers for the smaller quantities. I’ve had one or two infestations in individual containers, but they didn’t spread, thankfully! If I spot an infestation, I’ll brew with the grain sooner than later, or otherwise just throw it out. When handling infested grain samples, I’m pretty careful to do so only well away from the other grains! And, I give all containers a very thorough cleaning between uses. It’s probably a bit overboard, but I get annoyed if bugs get into the works!
Since getting rid of that infested grain, my bug problem is 99% over with.
We purchase our grain in 55 lb bags. Usually have two, maybe three bags sitting in my closet (summertime), or the utility room (winter time), as that is the coolest location with little or no humidity.
These bags will last for a month or longer, maybe even 10 weeks. Never had a bug problem. None.
Now…decades ago when a purchase was made from a local brew shop, we did have buggy grain. Their grain was stored out on the floor, in bins.
would you make any other food product if it was infested with insects? I wouldnt eat oatmeal that was infested with bugs, so I wouldnt brew beer with it either.
That’s my thinking, exactly.
When you put it that way [emoji1785] I had grain bugs in a bag I had just open back in 2010. The internet at the time just told me to freeze it and once I don’t see them anymore it’s good to go. That’s what I did… I don’t remember the beer.
I don’t consider them analogous situations.