13,703
edits
Changes
added Raf's technique of filling a vessel only 80% with fruit and beer, then topping up
In wood or steel (or glass or plastic).
Active fruit fermentation may cause fruit particles to clog the airlock or bung and prevent the vessel from venting pressure. This may cause the airlock to shoot off or worse. The Rare Barrel prevents this problem in vigorously re-fermenting beers by stabling foil over the bung holes of barrels of actively fermenting fruit beer rather than using a bung<ref name='Jester King on the Sour Hour pt. 1'>[http://www.thebrewingnetwork.com/the-sour-hour-episode-14/ The Sour Hour #14: with Jester King, pt. 1]</ref> (~52 minutes in). Raf Soef uses stainless mesh from a tea ball on the bottom of bungs to prevent fruit pieces from clogging the bung or airlock<ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1156796387681907/ Raf Soef's tea strainer modification]</ref>. Raf also suggests filling only 80% of the capacity of the vessel with fruit and beer, and then topping up after the re-fermentation of the fruit <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1186697904691755/?comment_id=1186735661354646&comment_tracking=%7B%22tn%22%3A%22R%22%7D Conversation with Raf Soef on MTF regarding re-fermentation of fruit and dealing with blow off. 11/30/2015.]</ref>.
When using whole fruit, it is typical for the fruit to be carried to and held at the top of the fermenter due to carbonation. Some producers have voiced concern over the fruit sitting for prolonged periods of time in contact with air and prefer to push the fruit cap down periodically (and to ferment in such a vessel as to allow this)<ref name='Jester King on the Sour Hour pt. 1'/> (~40 minutes in). If you are fermenting in carboys and feel that you are getting acetic character from the fruit cap being in contact with air you can swirl the carboy periodically. Note that many who have used whole fruit have not noticed any problem with a fruit cap being in contact with air, so you may or may not find that this is a concern for you<ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1170422922985920/ MTF facebook thread about fruit caps]</ref>.