In the first installment of this Exchange Rates series, we took a look at how to convert the base malts in an all-grain recipe to extracts in an extract or partial mash recipe. In this second post in the series, we’ll discuss specialty grains.
Specialty grains add flavor, aroma, and color to beer and contribute proteins and unfermentable sugars. Some of them also contribute small amounts of fermentable sugars. They generally fall into the following two categories.
Crystal and caramel malts have undergone a special stewing and heating process that pre-mashes each grain within its own husk. The internal starch is partially converted to sugar, and the heat of the roaster caramelizes and hardens these sugars, which are readily dissolved in hot water.
Roasted malts such as chocolate malt and black malt have been roasted in much the same way as coffee beans. Roasted barley, though not actually a malt, is also included in this category.
Most of the time, you can freely interchange such grains pound for pound (or kilo for kilo) between all-grain and extract recipes because the flavor, color, and aroma components are as readily obtained by steeping in hot water as they are from mashing.
Certain specialty grains can contribute some fermentable gravity points, but this is usually a small enough number that you can neglect it when converting recipes. If you do find that your gravity readings consistently come in lower than expected when using large amounts of specialty grains, you can easily make up the difference by adding some dry malt extract.
Don’t use specialty grains to boost gravity. Rely on them for their qualitative contributions and stick to extract for fermentable sugars.
Sometimes extracts already contain some specialty grains. For example, most light malt extract is made by mashing pale malt with some crystal malt. How might you account for what’s already in the extract when you convert recipes? In the third installment of Exchange Rates, we discuss how to consider extracts and specialty grains together to adjust your recipe for extract composition.