Great Grains: Mash or Steep?

March 1, 2013 By K. Florian Klemp

Friends often ask me to review their brewing recipes and strategies. With all-grain brewers, this usually amounts to minor tweaking of ingredients and proportions. For extract-steep and partial-mash brewers, though, I encounter common issues with regard to grain utilization, tricky concerns that are often glossed over in brewing instructions.

Extract-steep brewers often assume that any malted grain or even adjunct can be steeped to augment wort. Partial-mash brewers frequently assume that any mixture of base, kilned and specialty malts and adjuncts will play nicely with one another. In either case, the brewer can be left with a starchy mess, inadequate utilization and/or just plain lousy beer. Both situations are easy to dodge, and both are unique to the method of brewing. The solution is pretty straightforward for extract brewers, but a bit more complicated for the partial mashers.

Malts and Adjunct Grain

The interplay and utilization of grains—be they malted, flaked or raw—are complicated, but the following general classifications and rules of thumb should help untangle this mess for the intermediate and beginning brewer. Most homebrew shop websites and malting companies provide spec sheets on their products, and these are a great way to learn about each ingredient’s unique characteristics and contributions.

Specialty Malts (Steeping or Mashing)

Specialty malts include all of the caramelized (or crystal) malts, dextrine malt and roasted malts. Any malt with the prefix “cara” can be used for steeping. These include the lightest, called carapils, and all of the numbered caramel or crystal malts, Lovibond 3 degrees to 120 degrees. Dextrine malt can be used like carapils. All of the continental European caramelized malts are also suitable for steeping, with cool, descriptive names such as CaraAroma, Caramunich, Caravienne, CaraRed, Carahell and Carafoam. Special B is very dark caramel malt (about 180 degrees Lovibond) and can be included in that family.

All roasted malts and grains can be steeped. These include chocolate malt, black patent malt and roasted barley (unmalted). The Weyermann Carafa family of roasted malt comes in three shades, either regular or dehusked. The malts are increasingly popular for their versatility and mellow character.

Base Malts (Mashing Only)

Base malts are the workhorse malts for partial-mash brewers because of their diastatic power (enzymatic potency from alpha and beta amylase, measured in degrees Lintner) that converts starches to fermentable sugars and unfermentable dextrines. They are essential to mashing. They include, in decreasing order of diastatic power, American six-row, American two-row, pilsner, American pale and English pale ale malt. The malts you choose will make or break your mash, so select them carefully. Malted rye and wheat also have a fair amount of diastatic power and can be used in partial-mash brewing.

Kilned Malts (Mashing Only)

These are base malts that have been heated to slightly higher curing temperatures to impart toasted and/or malty flavors and aromas. The higher the temperature and longer the kiln, the darker the malt and lower the diastatic power. Vienna and Munich malts are fairly light, 4 degrees to 10 degrees Lovibond, respectively, and have sufficient diastatic power to convert themselves easily.

Darker versions of kilned malts include biscuit, amber, brown, Victory, special roast and aromatic. These are best used with sufficiently potent base malts to ensure conversion. They range roughly from 25 degrees to 50 degrees Lovibond, rendering them rather impotent enzymatically.