Changes

Aging is generally required for mixed fermentations that include Brettanomyces. Expect The necessary/ideal amount of aging time will depend on the microbes pitched, the pitching rate, and the desired final beer. Keep in mind that the beer will also continue to develop once packaged. For more straightforward beers with highly attenuative primary strains (like tart saisons), a reasonable final product with tartness and brett character can be reached in a few months. For more complex and/or acidic beers (such as flemish reds or beers approaching lambics) you may expect an aging time of at least 9 months, but preferably quite possibly as long as 12-18 months or longer. In general longer aging will allow more complex expression of the spectrum microbes present. Sour beer should be aged in an environment that minimizes high temperatures and exposure to oxygen. Drastic temperature fluctuations and changes in atmospheric pressure will cause a vacuum inside of the fermentation vessel causing water airlocks to "suck back" air into the fermenter. This could potentially contribute to [[Acetic Acid]] and [[Ethyl acetate]] (nail polish aroma in high concentrations) production by Brettanomyces, however the development of a pellicle can help protect against this. Filling the carboy to the neck will also help minimize the surface area of the beer that can be exposed to air. Avoid over sampling the beer (once every 3 months at the very most). It should also be noted that micro-oxygenation is helpful for creating certain flavors in sour beer, and many homebrewers have reported not having any issues with over exposure to oxygen using water-based airlocks.