Crystal malt is also called caramel malt, which reflects the color and flavor that it adds to beer. Some purists distinguish between the two terms, pointing out that British crystal malts are produced in a roaster, while caramel malts may be made in a roaster or a kiln, but we’ll sidestep that distinction. In either case, the barley is soaked and allowed to sprout, then the wet barley is heated for a time, allowing for saccharification of the kernel within the husk.
Then, it’s roasted or kilned at a higher temperature, which darkens the color and converts the sugars into unfermentable dextrins.
Crystal malt is typically sold by color from 10–120°Lovibond. The darker the color, the more pronounced the flavor, with the high end possibly contributing some bitter astringency. In the lower and middle ranges, crystal malt can add a nice nutty caramel complexity, but the sweetness can be cloying and simplistic if you use too much. As a result, it’s recommended to hold it down to 5–10 percent of the grain bill in your recipes.