Most brewing grains contain a significant amount of starch which must be mashed in order to convert it to fermentable sugar. If the grain is not mashed, the starches will end up in the finished beer, affecting the beer's clarity and mouthfeel, and no fermentable sugars will be available for the yeast.
However, some grains have been specially processed in such a way that they contain little or no starch. These grains can be used without a mash to add color, flavor, and fermentable sugar to an extract-brewed beer.
Malts or grains containing significant amounts of starch should never be steeped; the soluble starch will create serious problems in the finished beer.
How to steep grains
There are two considerations in steeping grains. First, sugar, flavor, and color must be extracted from the grain, which is done more efficiently by hot water. Second, the extraction of tannins from the husks of the grain should be avoided; this takes place at high temperatures. Several methods have evolved to preserve this balance.
The most common method of steeping grain is to raise the temperature of the boil kettle to 160°F (70°C) and simply soak the grain in a mesh bag or some other porous container while holding the temperature steady for 20 to 30 minutes. Unlike in a mash, no starch conversion is taking place, since most steepable grains contain no enzymes.
Some brewers take a less precise approach, adding the grain bag to the boil kettle before heat is applied and simply pulling the grain out when the boil reaches a certain temperature to avoid the extraction of tannins. While not as efficient as a temperature rest, this will extract a lot of the grain's flavor.
Some brewers go to extremes to avoid extracting tannins, steeping the grain for a long period (often 24 hours) in cold or room-temperature water.
Types of steeping grains
There are two major categories of steeping grains:
- To create crystal and caramel malt, the grain is essentially mashed in the hull, resulting in a malt that is almost entirely sugar already. These grains add sugar, including a high proportion of unfermentable sugars, to the wort, resulting in a distinct sweet taste in the finished beer.
- Roasted malt and roasted unmalted grains are processed with heat high enough to break down any starch directly. As a result, these grains will add roasted flavors and dark colors to the wort.
Specific types of grain that can be steeped are listed below:
This category has the following 2 subcategories, out of 2 total.