Thank you Darla Hoffmann for our sole response last week on Vine Growth Cycle!
This week: Beer
In the brewing process how does the roasting level of the malt influence the style and flavors of the final beer?
The roasted level of the malt has a direct effect on the final color and potential style of the beer. If you roast your malt “lightly” it will produce a clearer style of beer like a pale or bitter, if you roast it a little more it’s a golden, like a Scottish ale or marzen for lagers and tend to be a bit sweeter in character. The darker the roast level and produces a brown or dunkel, and even more roast and you get to porter and stouts, which in the contrary are typically lower abv and get the flavor and of coffee and mocha. Of course it will depends on the yeasts you are using for either a ale and lager style....
The most obvious result of the roasting level will determine the color as Chris said. For example, the longer the roast the darker the beer. However darker beers are not necessarily stronger. The roasting level may actually stump the starches in the beer so they can't be fermented meaning less materials for the yeast to turn to alcohol. This may give the beer a richer texture and mouth-feel but it will be a lighter alcoholic beer. However, all dark beers are not necessarily lower in alcohol and all light beers are not always higher. The brew-master can manipulate the roasting level, and fermentation process to determine a beer's final style. For the most part only a percentage of a grain is roasted which can have an effect on flavor profile. The use of different grains can also add to the flavor profile, i.e. adding roasted barley can give off burnt toast flavors.
On a related note, an ancient form of roasting the malt involved doing so over an open flame, imparting a strong smoky flavor to the beer. As kiln drying became more common and economical, the flame-drying fell out of fashion to remove the smoky taste in favor of cleaner flavor profiles. However, there are a couple of breweries in Germany--Schlenkerla & Spezial--that continue on with the tradition of Rauschbier--a specialty of Bamburg,