Bottle Conditioning Issues
Our wild beer is under-carbonated. To combat this we began by adding more dextrose at bottling. We increased the dextrose from 8.78 oz/bbl to 11 oz/bbl. That increase in dextrose did not solve our problem. Next, we added some yeast (3711) at bottling beginning at 1 million cells/ mL and increased to almost 4 million cells/mL. That did not solve our problem. We will be pitching champagne yeast at bottling next at a rate of 1.5 million cells/ mL. We have been with 2 different beers that have a primary fermentation with 3711 and extended aging in barrels with wild yeast and bacteria. The beers are usually at about 1.003 at the time of bottling and begin at 1.044 and 1.074. We condition our beers for up to 3 months at around 70F. Do you have any recommendations for how we might be able to solve this problem?
The low pH of your beer could be inhibiting your yeast. If that's the case, pitching Brettanomyces or blending with a young wild beer might solve the problem. Both of those methods could require a lot more time, though.
Do you expect the wild yeast to take the gravity below what you bottle it at or has fermentation completed?
If it's done fermenting then it doesn't seem like enough sugar to me. I'd add 16-17oz to get 2.5 volumes in a BBL. Might want a higher volume for the style though.
Anything in the capping system change lately or are you corking?
Fermentation is completed when we bottle our wild beer. The next thing we are going to do is try more dextrose. We may try sucrose. We have not changed our capping lately. We us a pneumatic capper and swap the bell out every few months. Does anyone else use sucrose?