This past July I got a couple 5-gal food-grade BPA-free buckets with Gamma lids locally. One had been used to store coconut oil so I did an especially thorough job of cleaning them both.
In August, a local store had Gold Medal unbleached flour (not my fave but not bad) at nearly half-price, so I bought several bags, put all but one into one of the pails, and put it in the cool corner of the basement (56-58ºF year-round). I used the other over the next few weeks and it was fine.
Yesterday I retreived one of the stored bags and made a loaf of white bread with it. It tasted horrible. Hard to describe, a plasticky-perfumy undertone to it. What did this? The search was on. Something plastic in the oven? No. And not the pan; I've used it dozens of times. I got the flour bag and took a whiff. Pee-uu. There it was. The same scent as the taste. Went to the basement, opened the pail, and it had the same odor. The flour had soaked it up for four months. The other pail was still empty but also stank (stunk?).
I examined the pail and saw the "HDPE" marking. Huh? HDPE = High-Density PolyEthylene. I had assumed these were polypropylene (PP).
I went to my storage jars cupboard and pulled out the plastic containers that had lids on them. Most were PP. A few were HDPE. The PP ones had no odor. The HDPE ones all had the same scent as the pail. How strong depended on how long it had sat unused in the cupboard. They are now in the recycling bin.
I'm going to leave the flour bags out for a few days and see if the smell dissipates. If not, into the garbage they will go.
I will never again use HDPE for food storage. It might be ok for short term (a few days) but not for long term.
edit - FWIW, this bucket is made by Bway, one of the biggies in the food packaging industry.
Thanks for the heads up. I'm guessing the smell will dissipate from the flour. Bad Bway.
I hope you're right, it would be a shame to throw all this flour away.
Sifting the flour might help by exposing it to much more air.
Gary
True...
I have several Leaktite brand food-grade HDPE 5-gal pails that I store various flours, grains, and food items. I have not noticed any odors over the past year in the pails or the foods that have been stored in them. Most of the items are in their original plastic bags in the pails.
I suppose it's possible that this is a mfr-specific issue; perhaps there are many HDPE variants. But since the interior of the HDPE containers in my cupboard that have been sitting covered but unused for several months or more have the same odor, I'm inclined to stop using the material for anything other than short-term (a few days) storage, preferably refrigerated.
That would make a difference, for sure. Flour in paper bags is more vulnerable.
I’ve been using HDPE food grade white 5-gallon buckets for several years to store flour and have never had an odor problem. However, I found the following info on the internet:
Is it possible you got some recycled HDPE? I wouldn’t give up on HDPE entirely, but I probably would get rid of the smelly containers. They don’t seem right for food.