A Craft Beer & Brewing Magazine reader recently asked us the following question:
I heard it may be good to steep some dark grains instead of mashing them. Why? What’s the best way to do it?
Steeping the darkest roasted grains is a method that Gordon Strong introduced to me in his book Brewing Better Beer: Master Lessons for Advanced Homebrewers. The reason to steep grains instead of mashing them has to do with the length of time it takes to mash your grains. The best analogy I’ve heard is to think about brewing roasted coffee beans to make coffee. If you brew the coffee for the correct amount of time (about 2–4 minutes for a French press), you get a nice enjoyable cup of coffee. However, if you were to steep the same coffee beans for an hour or more, you would get coffee that was sharp, bitter, acrid, and overly strong.
Gordon Strong argues that the same applies to dark-roasted malts, such as chocolate, black patent, roasted barley, and probably even many of the dark crystal and colored malts, such as dark brown malt, Special B, and light chocolate. Leaving these dark-roasted malts in the hot mash water for an hour or more runs the risk of extracting many bitter, tannic compounds that can upset the balance of your beer. Further, these very dark malts don’t actually contribute much in the way of fermentable sugars, so they don’t really need to be mashed. Steeping them for a short period in hot water is sufficient to extract the flavor and body from them.
The original method for handling these dark “steeped” grains was to create a separate tea using the dark grains. Steep them for a short period of time (perhaps 5–15 minutes) in hot water and then strain the grains out to extract the tea. However, many brewers found this to be time consuming.
The current method, which is much quicker, is simply to sprinkle the dark grains over the top of the mash before you lauter/sparge your grain bed. This limits the steep time but still lets you extract the flavor and body from the roasted grains. It also saves time and makes for easy cleanup as you don’t have to deal with heating up and straining a separate tea.
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