CRAYON off-flavor. Any ideas? Maybe crystal 60?

[hlmbrwng]

A few years ago, I bottled some imperial stouts and dipped them in wax, made from crayon and glue sticks. Not sure if anyone has tried doing that. I'll say right up front that this isn't the source of the flavor. I think it's one hell of a coincidence...

So I did the homemade bottling wax thing by melting crayons and glue sticks. Works great at first, but over time, no matter what ratio I use for crayon:glue, they start to crack. Actually bottling wax works much better. But I digress...Over time, one of the beers started tasting like crayon. I thought, immediately, that it was because of the homemade wax. But there were 3 variants of the stout, and only one seemed to taste like crayon. This one was aged on cranberries and raisons. I'm pretty sure I didn't heat the fruit long enough and it contaminated the beer. So, I thought, that's a funny coincidence. The off-flavor is crayon, and the wax is partly crayon. It must be the wild microbes that caused the flavor since the other beers didn't taste like that.

Fast-forward a couple of years later. I brewed the (mostly) same beer. I gave up on the homemade bottling wax. So, I wax these bottles with wax that was produced specifically for this purpose. The stout, after about 1 year again has this same off-flavor. I have used this new bottling wax for many beers and none of them have this flavor. Also, I'm pretty sure this time around it is not contamination. So, I think it's one of the grains, or a combination of grains that is causing this.

I have read that C60 does not do so well in beers meant for aging. Could this be the culprit?

 

[hlmbrwng]

Even if you do not know what the reason is, if you have experienced this off-flavor, I would love to hear about your experience.

The grain bill inluded:
Munich
German pilsner
Caramel 60
Flaked barley
Chocolate malt (350)
Roasted barley (525)
Black patent (500)

 

[GPP33]

I’ve never heard of C60 not aging well. I just brewed a Barleywine using 2 row and C60 so I hope it ages ok.

 

[isomerization]

If it was only 1/3 variants, wouldn’t this suggest it was the adjunct added after primary fermentation? Or are you saying the 2nd round did not include adjuncts?

 

[hlmbrwng]

If it was only 1/3 variants, wouldn’t this suggest it was the adjunct added after primary fermentation? Or are you saying the 2nd round did not include adjuncts?

That is correct. The second round did not include the same adjuncts, but has developed the same off-flavor. I've never had this occur in any other beer I've made, even other high ABV beers meant for aging.

Also, as far as only 1/3 from the first batch developing the flavor, it isn't really fair for me to say that. I drank the other 2 variants much faster. It's possible they would have developed the same character.