Mountain Brewer

Thanks all for the responses,

I may have miss spoke with saying CO2 kills the yeast as much as the pressure build up. I may be mistaken on this but it is what my brain thinks is happening. I came over to the distilling world from brewing about 6 months back so I'm in a little bit of new waters here. The high pitch temp should be able to be handled by the yeast as our rums are also in the 90's for fermentation temps and they kick hard and fast (same yeast but with a 50/50 rum yeast). The first strip of the 90 deg pitch was a great yield and I exceeded my standard ABV return. After transfer the temp was closer to 85 then in the 90's. I'm running more today. I have many more ryes to make so as I'm developing these pitch temps and SOP's I'll mess around and find the sweet spot. Any and all advice is taken in here so thank you. Below is a picture of the cap I walked into this morning. That is day 2 of fermentation.

Silk City, I have walked in many mornings cleaning up the floors of slop overflow lol labor of love! I'll punch it down and keep taking my readings to get a better understanding of what is happening. 

Kleclerc77,

Yes, we are using our house dry yeast, I put in go-ferm then add the yeast to the go-ferm slurry at minimum 30 minutes usually an hour before pitching. Then I throw the yeast into the mash ton just before transfer. This is an interesting point though because I pitched one batch at 90 degF and it did not cap. It did very similar to what you just described. The other 2 mashes I pitched around 80-85 degF and those are the fermentations I'm struggling with this cap. 

Hey all,

We are fermenting an on grain 95% rye. We ferment all of our whiskeys on grain given we don't have the ability to lauter/sparge. Our equipment is not set up for lautering. Particularly with our high rye and single malt, there is a 6"-12" grain plug sitting on top of the fermenter preventing CO2 to escape during fermentation. This has lead to bad yields. The lack of CO2 release is killing off the yeast. Recently I have been hooking it up to a pump to circulate 3-5 times a day or taking a SS paddle and mixing the grains back into the rest of the mash sitting below the grain plug on the top. After about an hour or two the grains get pushed back to the top where they dry and plug up the fermentation. We are using 300gal ACE Roto-mold plastic fermenters. Has anyone else had this problem, and come up with a better solution than elbow grease and a paddle?

Thanks