The
Malting Process and
Art of Crafting Specialty Malts
Malt, the heart of beer
Malted barley, or malt, is the basic ingredient used in the production
of beer, providing complex carbohydrates and sugars necessary for
fermentation, as well as contributing flavors and colors that are
uniquely characteristic of beer.
Standard malts, specialty malts
There are two main categories of malt: standard and specialty.
Standard (base or brewers) malts contain high amounts of enzymes,
complex carbohydrates and sugars necessary for fermentation. Specialty
malts are produced when the length of time, temperature or humidity of
the three stages of the malting process—steeping, germination and
drying— are adjusted to develop unique flavors and colors, or
distinctive functionality. Additional drying decreases the amount of
enzymes and sugars available for fermentation, so many specialty malts
are designed to be used in smaller amounts to contribute unique
flavors such as intense malty, sweet caramel, nutty, woody, coffee or
burnt, and rich colors ranging from golden to red to black. Making
specialty malts differs from the basic malting process in that batch
sizes are generally smaller, it is a much more labor and resource
intensive process, it involves more laboratory testing for
consistency, and it requires the constant vigilance of an experienced
maltster who relies upon his senses of sight, taste, smell and touch
to achieve the desired finished product from the beginning to the end
of the process.
Why barley?
Barley is the ideal cereal grain for malting and, ultimately, brewing.
It is self-contained, having a husk to protect the germ, high
starch-to- protein ratio for high yields, a complete enzyme system,
self-adjusting pH, light color and neutral flavor. In addition to
barley, wheat and rye are also routinely malted for brewing. Other
cereals grains, such as buckwheat and spelt, can also be malted but
the finished malt does not perform in the brewhouse as well as malted
barley.
Step one—Steeping: The basic malting process, although
more of an exact science today than when man first dipped baskets of
grain into open wells in Mesopotamia 5,000 years ago to prepare it for
brewing, remains a three-step process: steeping, germination and
drying. During steeping water is absorbed by the raw barley kernel and
germination begins. Steeping starts with raw barley that has been
sorted and cleaned, then transferred into steep tanks and covered with
water
For the next 40-48 hours, the raw barley alternates between submerged
and drained until it increases in moisture content from about 12% to
about 44%. The absorbed water activates naturally existing enzymes and
stimulates the embryo to develop new enzymes. The enzymes break down
the protein and carbohydrate matrix that encloses starch granules in
the endosperm, opening up the seed's starch reserves, and newly
developed hormones initiate growth of the acrospire (sprout).
Steeping is complete when the barley has reached a sufficient moisture
level to allow uniform breakdown of the starches and proteins. One
visual indicator that the maltster uses to determine the completion of
steeping is to count the percentage of kernels that show “chit”. Raw
barley that has been properly steeped is referred to as "chitted"
barley, the "chit" being the start of the rootlets that are now
visibly emerging from the embryo of the kernel.
Step two—Germination: In a process called "steep out," the "chitted" barley is transferred from the steep tank to the germination compartment. Germination, which began in the steep tank, continues in the compartment where the barley kernel undergoes modification. Modification refers to the break down of the protein and carbohydrates, and the resulting opening up of the seeds' starch reserves. Good modification requires the barley to remain in the compartment for 4-5 days. Germination is controlled by drawing temperature-adjusted, humidified air through the bed. Turners keep the bed from compacting and rootlets from growing together, or felting.
Step three—Drying: Germination is halted by drying. If
germination continued, the kernel would continue to grow and all of
the starch reserves needed by the brewer would be used by the growing
plant. Drying occurs either on a kiln or in a roaster, or both, and is
key to developing the flavor and color characteristics of the finished
malt. Base malts are typically kilned with a finish heat of 180-190 º
for 2-4 hours which develops flavors ranging from very light malty to
subtle malty. Specialty malts are kilned at higher temperatures for
longer periods of time, roasted, or both. Varying the moisture level
and time and temperature of drying develops the flavor and color
characteristics of each specialty malt.
