"Cardboard" aroma/taste

[bconley]

Hey all...Weird question. Two weeks ago, we did our first 100% corn mash instead of our usual rye-forward bourbon mash, and everything looked and smelled normal throughout the ferment, not too different then our usual mash. PH looked fine, everything was good. Low wines smelled normal as well. We mashed that same 100% corn recipe again last week, and the ferment had a different, "cheese" smell. Okay so the alarms in my head started to sound right away. We went ahead and did our low wines run, and it has a distinct "wet cardboard" aroma. I've smelled and tasted this in a lot of the craft bourbons I've tried, and I was wondering if anyone knows what I'm talking about and can help point out what causes that. We are giving our fermentation tank a deep, DEEP clean in case there is something off growing in there

[Golden Beaver Distillery]

Mold in the corn would be my guess.

[Foreshot]

I second the mold suggestion. I had a batch from a local farmer and it was bad to begin with and went worse from there. If the corn wasn't properly dried out or it got humid in storage it will go bad quickly. The sucky thing part was that aside from losing a couple batches it was a test with Creole Orange corn. It had an awesome taste hidden behind the cardboard taste. Haven't had a chance to try it again.

[bconley]

Thank you for the responses! I hadn't really thought about mold, because it tasted so much like craft whiskey's I've tried (without naming names) from Brooklyn to here in Ohio to Sonoma, and while I didn't like it, couldn't imagine someone making that and going "Mold? Go ahead and sell it". It has been humid here lately, and the bags of grain are not stored in climate controlled areas, so some moisture from the air may have taken hold of the remaining bags. It was just strange because the bags on top all produced a normal batch, but then one layer lower and we get the cardboard.

[kleclerc77]

Dang I just got my first ever cheesey ferment. The weird part is, only one of the two ferments I did got cheesey. So it doesn't seem like the grain is to blame. Did you ever come to any conclusions on this @bconley?

[Foreshot]

I forgot about this thread. I did a little research but did not report back. It could be a low level of butyric acid. Stephen from BA had the same issue & he analyzed it as such. Most likely from an infection. Yeast can produce it too though I don't know the level/reasons.

http://www.milkthefunk.com/wiki/Butyric_Acid

https://onlinelibrary.wiley.com/doi/pdf/10.1002/j.2050-0416.1979.tb06846.x