Welcome to the Montana State University
Malt Learning Center!
What is malt?
Malt, in terms of beer or distilling, is an important natural ingredient most often derived from barley which largely dictates many aspects of the beer in your glass - including: alcohol content, flavor, mouth feel, and color.
Why do we say "No Barley, No Beer"?
(when there are also other grains malted?)
Barley has two important aspects as a malt that other grains don't live up to. Barley has a husk and produces more enzymes than other grains. These are important attributes to the brewing process:
1) the barley hulls aid in beer filtration - beers made without enough barley need added rice hulls or other filtration aids
2) The high enzyme potential of barley (which has a multi cell aleurone layer to produce more enzyme compared to the single cell layer of other grains) allows efficient conversion of starches to sugars for fermentation. Beers utilizing adjuncts such as rye, oats, rice, corn, wheat etc benefit from a high % of barley base malt in the grist bill to provide enzymes for full starch conversion.
How is malt made?
Malting follows three basic stages: Steeping, germination, kilning
The steeping phase brings grain up to ~45% moisture (from ~12% at harvest) over a period of about 2 days. Alternating between periods of steep and air rests allows the grain to take up moisture and triggers a sense of "spring rain conditions" in the grain. This moves the grain into germination
This phase is typically 3-5 days and allows the biological changes in the grain which break down cell walls and protein in the grain, exposing starch granules and preparing them for the brewing process.
For base malts this phase takes roughly a day and utilizes low slow heat to dry the grain down to ~5% moisture, making it stable for storage. Specialty malts can also be made in the kiln when modifying timing, moisture, and temperature. Much of the color and flavor in malt is developed during the kilning phase.
Grain Stages as Malting Progresses