DMS, or dimethyl sulfide, is a chemical compound that can be found in many types of food and drink, including beer. While it is present in small amounts in many beers, it can be a “silent killer” of good beer if it is present in too high of a concentration.
How does DMS get into my beer?
DMS is produced during the boiling of wort, the liquid extract of malt that is used to make beer. It is formed when a compound called SMM (S-methylmethionine) is broken down by heat. The amount of DMS that is produced depends on a number of factors, including the type of malt used, the length of the boil, and the temperature of the boil.
In small amounts, DMS can give beer a subtle, slightly sweet, and vegetal flavor that is often described as “corn-like” or “cabbage-like.” In these small amounts, it is often considered a desirable flavor in certain styles of beer styles .
However, when the concentration of DMS is too high, it can overpower the other flavors in the beer and give it a “canned corn” or “vegetable soup” aroma and taste. This can ruin the overall flavor of the beer and make it undrinkable.
There are a few ways that brewers can minimize the production of DMS in their beer. One way is to use malt that has been modified to reduce the levels of SMM. Another way is to boil the wort more vigourosly, as the DMS will leave with steam and other volatile compounds
It is important for brewers to carefully monitor the levels of DMS in their beer to ensure that it is not present in too high of a concentration. While a small amount of DMS can add complexity to the flavor of a beer, too much can ruin it completely. By paying attention to the production of DMS and taking steps to minimize it, brewers can help to ensure that their beer is as good as it can be.