Diacetyl in beer brewed by craft beer equipment. Beer is a kind of wine with a variety of flavors. It briefly introduces the diacetyl bar in beer brewed by craft beer equipment, so that you can learn more about how to make good beer with superior quality.
Diacetyl is one of the metabolites in the yeast fermentation process, and its content has become the basis for judging the ripeness of beer. At present, the formation mechanism of diacetyl is generally considered to be an intermediate product of yeast synthesis of proline, a decomposition product of α-acetolactate. According to their respective experiences and actual conditions, each beer manufacturer selects suitable yeast varieties, adjusts the composition of wort and reasonable fermentation process, and also adds α-acetolactate decarboxylase to produce beer of its own style. Diacetyl reduction is no longer a problem, but beer The rebound of diacetyl in production is one of the problems encountered by many manufacturers.
The diacetyl rebound means that the diacetyl value rises during the storage or during the filtration and filling process. During the storage of the wine, the diacetyl rebound is generally caused by pollution or the beer produced by the two-tank method. The oxygen is inhaled during the pouring process. Production series of new Samsung beer, in addition, from the functional department to the production workshop to pay attention to process hygiene, there has not been a double-acetyl rebound during storage, but after the filtration and filling, there is a diacetyl rebound, resulting in diacetyl threshold in the national standard or exceeding the standard. Guarantee the quality of shelf-side products and not leave the factory, causing certain economic losses, and some have happened.
There are two factors in the analysis of the diacetyl rebound in the filtration and filling process: one is the presence of diacetyl precursor α-acetol in the fermentation broth; the other is the oxygen inhalation and temperature rise during the wine, filtration and filling process. As a result of the above two points, after the pasteurization, α-acetolactate undergoes non-enzymatic oxidative decarboxylation to form diacetyl, which causes the diacetyl value to rebound to varying degrees. Generally, the diacetyl value increases (0.01-0.02) mg/l after sterilization. But excessive growth is something that should be avoided.