Originally Posted by Bobby_M
Hey Mike, what are your thoughts on when to fruit a barrel lambic? We're embarking on a two-barrel Framboise next month. The cab barrel is well inoculated with bugs and I was thinking the base wort will just go directly into the barrel for primary. Once the initial gravity is dropped over a month, I though the fruit would go in. I already know your opinion on fresh vs. concentrated fruit juice but I don't think most of the shareholders are willing to drop $40 each on fresh fruit. 6 quarts of concentrate is the equivalent of about 120 pounds of fruit (in one 60 gallon barrel).
Do you see any reason to repitch regular beer yeast in addition to the bugs in the wood? We've been doing a 5 gallon boiling water rinse between batches so far.
My personal preference is to add the fruit later on, say after 6-12 months of age. That way the Brett and lactic acid bacteria are the dominant microbes and will get to eat the fruit sugars. Waiting also lets you see how the beer is without fruit, and allows you to save some un-fruited beer. With our barrels we have left the fruit out and allowed individuals to pull off their shares onto fruit if they want. This way each person can control the quality/amount/time, and you can have some interesting comparisons.
Fruit concentrate can certainly work, I recently heard Will from Cambridge brewing mention that he uses it with good results. Just be careful, unlike fresh/frozen/juice/puree which wont raise your gravity much, concentrate will boost the alcohol considerably.
Ive yet to do a barrel without a healthy culture of bugs going. For the first round we added 10 gallons of 6 month old sour for bugs (this is how Rodenbach re introduces bugs after they strip down a barrel for cleaning). Most of the rest of the beer had been fermented out already by Sacch, although we added some fresh wort to get the bugs going. For the second fill for each barrel we racked beer/wort in after pumping the previous beer out without rinsing. After this round we may give the barrels a rinse, but we still have plenty of time to think about it.
For the solera I had some month old sour beer that was mixed with the first half of the wort, a week later we brewed/racked the second 30 gallons of wort (taking 5 gallons out to give the fermentation some head space). This one got sour much faster than our other barrels, but that may have been the specific strains we used etc
I had bad luck underpitching my first batch of Lambic, so be careful. I dont know how quickly fermentation will start if you are just relying on the bugs in the wood. It might be worth getting 5 gallons going first with some blend, and letting complexity come from the bugs in the wood.