Changes

Full - <span style="text-decoration: line-through;">A storage solution of 1 g citric acid and 2 g potassium metabisulfite per L (or 1 lb potassium metabisulfite and 0.5 lb citric acid per 225 L barrel<ref>[http://www.thebrewingnetwork.com/the-sour-hour-episode-5/ The Sour Hour with Tim Clifford of Sante Adairius]</ref> (~40 min in)) is often used. </span>  ''Update:'' Jay Goodwin from The Rare Barrel reported getting residual sulfur off-flavors in beers which required from using too much metabisulfite in their barrels. The beers needed extended aging for the sulfur to be volatilized off. Eric Salazar from New Belgium Brewing advised that they cut the metabisulfite content down to 1 ounce per 59 gallon barrel (~0.017 ounces per gallon/~0.127 grams per liter), and to check the barrel once a month and change the storage solution once a month if needed. The amount of citric acid is the same: 0.5 lb per 59 gallon barrel (1 gram per liter/0.13 ounces per gallon) <ref>Private correspondence with Mike Makris from The Rare Barrel by Dan Pixley when asked to clarify the amounts that Eric from NBB recommended. 03/06/2016]</ref>. Before using a barrel holding this sort of storage solution, the barrel should be rinsed thoroughly.