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This month's question: What causes the rich malty flavor in beers such as Bock or Oktoberfest? How can I get that flavor in my beer?
Answer: German beers, especially the darker beers, have a rich malty flavor that seems to be pretty unique to their region. Although there are many malty amber beers in the world, most get their malty richness from crystal malts. German beers, though, take a different approach. Many of them have no crystal malt at all. Instead, they rely on a family of chemical compounds called melanoidins. Melanoidins are formed when sugars and amino acids combine at elevated temperatures, typically around the boiling point. In contrast, the sweet caramel flavors associated with crystal malts form from higher temperatures. To get a good feel for the difference in these flavors, try doing a head-to-head taste test of a British Pale Ale with a German amber lager such as Oktoberfest. Even though you can find examples with the same color, the nature of the maltiness will be quite different.
There are several different ways to get melanoidins in your beer. These can be used in various combinations depending on the type of brewing you do. One method is to use malts that come with considerable ready-made melanoidin content. The other method is to form your own melanoidin by including some extra boiling steps in your brewing day.
Two malts with high melanoidin levels are Vienna malt and Munich malt. Of the two, Munich malt has more, and in particular, the darker the grade of Munich malt, the stronger the higher the melanoidin content. These malts are made by slowly drying the malt as the temperature is raised, allowing the melanoidins to form as part of the kilning process. At the top end of the scale is a specialty material called melanoidin malt.
If you are an extract brewer, the easiest option is to buy Munich malt extract. You can use this just like the regular malt extract. In addition to getting a richer melanoidin flavor, you beer will be darker color and the final gravity will be a bit higher. A simple additional step to take is to buy a small amount of melanoidin malt and steep it like you normally would steep crystal malt. About half a pound per five-gallon batch works well. If you do a partial mash, try using the dark Munich malt to fill your mini-masher. The diastatic power of the Munich malt is lower than pale malt, so you might want to add some pale malt in as well.
The other method is to include extra boiling into your brewing day. A typical one hour boil will generate a small amount of melanoidin. This is evidenced by the darkening of the wort that occurs during the process. As you might imagine, adding extra time to the boil will increase the amount that is formed. If you use this approach, you will need to compensate for the extra water that is boiled off in the process. If you are making a high-gravity beer such as Bock, this becomes an integral part of the process. Also, remember to not add the hops too early. Put in the extra boiling time prior to the first hop addition. Best results will be attained if you check the gravity of the wort late in the boiling process and top up the level if necessary. .
If you are an all-grain brewer and want to get the ultimate amount of rich and smooth melanoidin, you need to use a decoction mash. This is a process where you take a portion of the mash and bring it up to a boil. Once the decoction is completed, mix the boiled mash back in with the portion of the mash that was not boiled. The combined temperature then raises the temperature of the whole mash tun up to the next target temperature. In this manner, the mash will be brought up in steps from protein rest, through saccharification, and finally up to mash-out temperature. The amount of melanoidin depends on the number of decoction steps you use in the process. A typical method is to use double-decoction. Some German breweries use three or four decoction steps along the way.
Regardless of the method you use to add melanoidins to you beer, you're sure
to find that those German beers you've been trying to make suddenly taste a
lot more authentic