Changes

Typically, only low alpha acid hops are used (high alpha acid hops may lead to more hop character and higher inhibition of lactic acid bacteria than desiredpossibly due to oxidized acids). The hops are typically bound in burlap sacks/paper bags or something similar that allows for exposure to oxygen, and then they are left to age in preferably low humidity conditions at room temperatures to warm temperatures (warmer temperatures will encourage faster aging). Changes in the environment such as temperature shifts are not a concern; for example [https://web.archive.org/web/20180204131402/http://jesterkingbrewery.com/home-for-our-aged-hops Jester King Brewery in Austin Texas ages hops in a horse barn]. The hops should are traditionally aged for 2+ years. Monitor for mold growth during this time, and discard any hops that show visible signs of mold growth. Some brewers prefer to age the hops until the cheesy character ([[Isovaleric Acid]]) is gone, while other brewers do not mind the presence of this cheesy character (for example, some [[Lambic|lambic]] beers display isovaleric acid character even after packaging). While hop leaves are generally preferred over pelletized hops, if aging pellets, it has been advised to break the pellets up so that the entirety of the hop material is exposed to the air.