Thp in bottling wild ales

If you check out the Sour Hour podcast with Jay from The Rare Barrel, they address it quite a bit. Unfortunately pro-brewers have similar issues with thp, and there aren’t many ways to avoid it besides to try to avoid oxygen pickup. I’ve only had one batch of beer with really intense thp and it took a good 5-6 months in the bottle to clean up. It was a Brett fermented British Mild w/ cherries that had a lot of headspace during secondary on the fruit. My guess was that was my issue.

 

call me country bumpkin, but |I'm not familiar with the term THP. Can you explain what that is?
Thanks.

 

Tetrahydropyridine - an off flavor that reminds people of certain cereals like Cheerios or CapNCrunch transitioning to mouse urine as it becomes more concentrated.

 

My experience is that it's hard to avoid and just takes time to age out. Minimizing oxygen pickup, as @Davl22 said, is key. I've taken to closed-transferring sours/brett beers to purged kegs and then using my beer gun to bottle, which seems to help.

 

I would transfer via a self-priming pump to a purged keg and then bottle off of that with the beer gun, personally. Bottling directly from the barrel with a beer gun would be difficult unless you have a way of reliably pressurizing the barrel with CO2 while doing so. In theory it could be done with a dual-port bung.

 

I’ve never encountered THP in any of the mixed ferment beers I’ve made which is somewhere around 10-12 that I’ve bottled (need to bottle about that many still). I’ve experienced It in a lot of other homebrewed mixed ferment beers but not in my own. From everything I gather it’s very much oxygen related.

I typically do a primary clean ferment then transfer to a carboy and fill as close to the neck as possible before adding the mixed culture. After X amount of time I’ll force transfer to a very well purged keg and add sugar and yeast (if it’s low pH a terminal acid shock starter) while I’ve got gas hooked up and then purge headspace quite a few times. I’ll let it sit for a few hours to homogenize, maybe shoot some Co2 through the liquid out then bottle using a beer gun. It’s a lot of steps but I don’t get any THP.. at least yet.