Vocabulary Lesson – Dimethyl Sulfide (DMS)

Dimethyl Sulfide, more well-known by its initials (DMS), is a compound causing flavors and aromas considered an unacceptable in most beer style. DMS causes a creamed corn or cooked vegetables flavor and aroma when found in beer at detectable levels. When present at high concentrations, DMS can cause more of a rotten vegetable aroma and taste. Although it is considered an off-flavor in most styles, DMS is actually a desirable trait and/or acceptable in small quantities (complementary and adding to complexity) in most pale lagers, such as a German Pils and Munich Helles, and some light-colored ales, like Cream Ale.

The most common way to form DMS is in the brew kettle. The precursor of DMS is the compound S-Methyl-Methionine (SMM), an amino acid formed in barley during the germination stage of malting. Once the germination (tricking barley into sprouting) is complete, the malt is then kilned (heated) to remove moisture then kilned even further depending on the type of malt that is being created. SMM is a thermally liable compound, which means that it reacts at a certain temperature and creates something else. Lightly kilned malts, such as Pilsner Malt, are not subjected to excessive heat for large periods of time and retain much of the SMM found within. Mashing (steeping malt in hot water) is usually done at a temperature that does not create DMS. However, it will release SMM into the wort (sweet liquid created in the mash) and is carried over into the kettle. When SMM is in the kettle and the wort is boiling, it create DMS.

Along with SMM, there is another compound is responsible for DMS. Dimethyl Sulfoxide (DMSO) is created when DMS gets oxidized and this can happen either in the kettle or already be present in the malt. DMSO is not as volatile as DMS and is not heat sensitive, therefore, it would remain dissolved in the wort even after boiling. DMSO is then reduced into DMS in the fermenter by yeast during fermentation. Since top-fermenting (ale) yeast tends preform more vigorous fermentations, the production of Carbon Dioxide (Co2) can literally scrubs away some of the DMS compounds out of the fermenter via the blow-off valve. Conversely, bottom-fermenting (lager) yeasts preform much slower so more of the DMS created from DMSO during fermentation can remain in the beer because the Co2 production is not as energetic. This is yet another reason why pale lagers tend to have higher levels of DMS compared to other styles.

DMS is quite volatile and generally escapes the brew kettle as steam with no issue. Homebrewers will encounter this as a problem if they cover the pot of boiling wort or before it has cooled down. The condensation collected on the cover is full of DMS and simply falls back into the wort. Other major contributors are a the use of high-protein malt such as those made from 6-row barley, lack of a vigorous boil, not cooling down the wort quickly enough, or bacterial infections from bacteria such as Enterobacter.

Thanks for reading. I hope you enjoyed it and learned a thing or two. Class dismissed!

Cheers,

Gilbert “Charlie” Perez, Certified Cicerone®


References:

https://beersensoryscience.wordpress.com/tag/dms/
"Beer: Quality, Safety and Nutritional Aspects" by by Paul S Hughes (Author), E Denise Baxter
"Malts and Malting" by D.E. Briggs

Doppelbock: Liquid Bread

Paulaner's Salvator Doppelbock

We've all heard beer referred to as “liquid bread” once or twice before. This analogy can fit many styles such as a Bavarian Weissbier or Belgian Quad. But, there is one beer style with greater affinity to "liquid bread" than any other: Doppelbock.

This beer style has a strong footing in Munich as a place of origin and monks are credited for its creation. Although that may be (somewhat) true, the actual origin story begins in northern Germany and the monks were from another neighboring country. Puzzling, to say the least. Let’s explore where this style came from and see if we can bring these two puzzle pieces together, shall we?

The story of Doppelbock begins in the city of Einbeck, located in northern Germany, in the mid 1500s. Einbeck was a thriving trade city and its specialty trade item was beer. This ale was made with lightly kilned barley & wheat and was generously hopped. Einbeck's beer made its way into many cities and that included Munich. The ruling family of Bavaria were particularly fond of the Einbeck brew. Plenty of money was being spent on this beer. Some brewmasters from Einbeck were brought to Munich in 1540 to teach the Munich brewers a thing or two.

In 1612, Duke Maximillian I(the first) convinced well-regarded Einbeck brewer Elias Pichler to move down to Munich and improve the Einbecker clones that were available. Pichler refined the brew to fit the parameters he had. This meant the Einbecker no longer contained wheat malt as this was reserved for special beers made for the royal family and employed the lagering tactics that were already well established by Munich brewers. The resulting beer was released at the famous Hofbräuhaus in 1614 and it was referred to as brewed the “Einbeck way.” We now have the birth of what eventually evolved to what we know as the traditional bock, or Bockbier. One puzzle piece down.

Now to discuss the he second puzzle piece: the monks. In 1627, they came marching in from Italy over the Alps and took home near Munich. Wait... Italy?! That's right, Italy. These monks were from the order of St. Francis of Paula. They wasted no time and began brewing shortly after arriving. These Franciscan monks established the Paulaner Brewery in 1634 and lay claim to the Doppelbock style. However, it went by another, more divine name. More on that later.

Before we move on, a quick note on how “Bockbier” got its name. It is widely believed and accepted that it is a manipulation of the word “Einbeck” in the Bavarian dialect. This would make the word sound like “Ayn pock” and eventually evolving to “ein bock” (one bock). “Bock” is also the word for “buck” or “goat” in German, explaining why so many versions of Bockbier display goats on their labels. That is quite ironic when you think about it. We consider the development of the Doppelbock style was a by-product of a testament of faith, yet the goat has some satanic symbolism.

(So metal! \m/)

Ahem... Moving on...

As with most devout Catholics, Lent was taken very seriously. During this time, the monks would not eat solid food and only liquid was allowed to be ingested. With Lent being the longest period of fasting for them, plenty of liquid would be consumed, most of which was the bockbier they were already experts at producing. Over time, and after receiving blessing from the Pope himself to consume such a wonderful beverage during Lent, the bockbiers got stronger. This was literally liquid bread for the Paulaner monks. It was only natural the beer was referred to as “Salvator,” as in “The Saviour,” for obvious reasons. In 1780, Paulaner was finally granted permission to brew commercially.

After the brewery came under Napoleon’s control in 1799, it lay in shambles until 1806 when it was rented a brewer by the name Franz Zacheri, ultimately purchasing it by 1813. Following a stretch of legal battles, in 1837 Zacheri finally was given permission by King Ludwig I(the first) to brew “Salvator” without obstruction. Clones were soon being produced by other breweries. The Schmederer brothers, Zacheri’s heirs, wisely trademarked “Salvator” in 1896. Paulaner is now the only one that can use the name “Salvator” for its Doppelbock. This is why we see other Doppelbocks with names such as Celebrator or Optimator keeping the “-ator” suffix since they cannot use the original name.

Ayinger's Celebrator

If you are not the fasting type, pair your Doppelbock with game meats such a venison or wild boar. Fruit sauces are great complements to both the meat and the sweet malt character of the beer. For an interesting combination, try Doppelbock with earthy, smoky Mexican dishes such as Oaxacan Mole. Don’t stop with the main course and try a caramel flan for dessert with a Ayiger's Celebrator (pictured above). If you are looking to pair with cheese, reach for Swiss Gruyère.

Doppelbocks are quite amazing and flavorful, but be cautious at that seemingly gentle touch. These beers are made for sippin’ as they span from about 7.0% to 10.0% ABV. Colors range from mahogany to deep garnet to almost black in some examples. Aromas are almost like rising bread in the oven. On the palate, you’ll get toasty and bready notes, slight caramel and toffee sweetness, finishing off with a moderate bitterness and a clean lager character. The darker versions have some chocolate flavors, too. Silky, full, and round on the tongue and finishes malty and clean. Serve in a traditional dimpled mug at 40°F, take your time, and enjoy what the monks gave us.

Prost! 

-Gilbert "Charlie" Perez, Certified Cicerone®




References:
The German Beer Institute
The Brewmaster's Table: Discovering the Pleasures of Real Beer with Real Food by Garrett Oliver