Changes

Acetylation (acetate) variations:

* 3-sulfanyl-4-methylpentyl acetate (3S4MPA; ''passionfruit'', ''grapefruit'')

Typically, in beer and wine, the amount of free thiols that are formed from these precursors is less than 1%, perhaps due to poor activity of β-lyase activity in acidic media and inhibition by polyphenols. However, these thiols were found in beers dry hopped separately with Amarillo, Hallertau Blanc, and Mosaic hop varieties. The amounts of these two thiols were higher than expected based on the content of these thiols in the hops alone <ref name="Cibaka_2016" />. Dry hopping temperature plays a role, with with 18-24°C being optimum for 3Mh and 3MP, and 28°C being optimum for 3S4MP. Mash hopping can potentially increase thiols, while using copper in the brewing or winemaking process can reduce them <ref name="Svedlund_2022" />. [[Omega Yeast Labs]] has bioengineered a yeast strain called [https://omegayeast.com/news/cosmic-punch-new-thiol-boosting-strain Cosmic Punch™ (British V OYL-011)] to produce significant amounts of thiols from hops and malted grains. [https://berkeleyyeast.com/available-yeast-strains/ Berkeley Yeast] also offers bioengineered yeast strains that produce thiols. See also this [https://www.facebook.com/groups/MilkTheFunk/permalink/1373899592638251/ MTF thread speculating on how ''Brettanomyces'' might produce thiols].