Cold Steeping Dark Specialty Grains
Guest Post: By Chris Mendez and Mark Widdifield
Cold Steeping Dark Specialty Grains
So, you want to make a dark beer of some kind but don’t want to invite in the tannic, astringent or otherwise sharp/acidic flavors that dark and very-dark roasted malts can sometimes bring to the party? Then maybe cold steeping is your answer.
Why cold steep?
Hitting dark roasted grains with mash and sparge temperature water can pull out a wide range of flavor components, some of which may clash with the other elements in your beer. While stouts, porters and the like are the usual homebrewer suspects for a cold steeping treatment, dark European styles, or anything begging for color and flavor components can be fun candidates for this process. Black ales and lagers (think BIPAs and schwarzbiers) may be the best candidates for cold steeping dark grains because they are on the light spectrum of dark beers and the tannins and even the roast can over power in these brews. While certain styles, grain ratios and most importantly your taste preferences may not make this a critical step, experimenting with this treatment can yield some fun riffs for tried-and-true recipes or for a new experimental batch.
Why cold vs. hot?
The best analogy may come from another single-element food product: Coffee. Like malted barley, coffee begins its glamorous life as a humble, raw and sort of unexciting seed, being magically transformed by a drying, sometimes light fermenting, and roasting process. That transformed bean then crushed and with water added to it can yield very different results depending on whether that water is cold, warm, hot or boiling. The time that the coffee swims is also a factor. You could experiment with this at home or by visiting your local barista, noting the difference between hot vs. cold-pressed/cold-steeped coffees even with the same bean, same grind and tasted at the same temperature.
The same can be extrapolated from dark roasted malts: hitting them with strike and sparge-temperature water compared to water well towards or below 70F can yield dramatically different flavor and aroma components, often similar to the coffee results: softer, subtler and avoiding tannic, harsh and astringent dynamics but still pulling out those chocolate, caramel and yes, coffee flavors that you wanted. Is this universally true? No, so if you’re curious about this method, have some fun experimenting with time and temperature of your cold steep. Now, with dark malts in general, boil time, mash pH, your water chemistry, brewing salt additions as well as overall process can also impact the end result but those are a much more involved deep dive. In general, use the same clean, contaminant-free water you would use to brew. Then…
How do I cold steep?
The simple answer is to add cold water to your dark malts, let them steep, strain the resulting extract and add to your wort or beer. The more complex answer is: it depends. Do you want a light color extraction? You want to make black mud? Hit some mid-temperature notes? Or cut it off after a few hours? Your call. That’s the fun.
But for a first attempt, here’s a basic process: Pick an appropriate dark recipe but segregate and separately mill all the 100L and above malts. Place all those dark milled grains in a nylon or muslin bag in an appropriate sized vessel to accommodate a ratio of between 1.5 and 2 quarts of water per pound of grain. Refrigerate this vessel overnight before brew day. On brew day pull out the bag of grains and let the excess run off. Squeeze the bag? Sure. Conventional wisdom says squeezing hot steeped or brew-in-a-bag grains doesn’t actually extract tannins as previously thought (pH has a more significant impact on this) so on the cold side it may not impact that factor and you’ll yield more product. If you don’t have a big bag, you could mix it up like a giant French press, fridge, then strain through a kitchen sieve. But beware, those very fine particles are along for the ride, so you should see some settle out.
What about infection?
This can be a genuine concern if steeping with room-temp or warmer water overnight especially with a higher fermentable content. Depending your grain bill, significantly more sugars may be present which can present a possible lactobacillus or other wild microbe infection. The fix? You can generally solve this by placing the steeping grains in the refrigerator overnight and any opportunity for infection will be slowed. Since the amount of your steep grains is small, any infection will only be 24 hours old—any will boil out.
When do I add the extract?
The cold extracted product can be added at any point in the boil, after knock-out or even to primary or secondary. However, the earlier in the boil, the more likely the very products you were trying to avoid can be pulled out, so adding late to the boil (say the final 10-0 minutes) not only minimizes this factor but can allay any infection fears you may have. is also an option, of course being careful about sanitization and avoiding oxygenation. If you add the cold steep wort post-fermentation, you could bring your steep up to pasteurization temperature, put in a sanitized container, chill then add.
Cold Steeping on the professional level is many fold more difficult than even a large format/scale homebrewer. Large format systems in professional breweries are not usually set up to introduce large volumes of cold steep extract. Can it be done? Sure. Has it been done, probably. But in order for a professional brewery on a large system to cold steep, they would need to refrigerate large volumes of dark grain. But then how and when to add that cold steep to the boil kettle? Maybe serving tanks in the cooler? But then a large format brewery would need an available tank not holding precious money- making beer, which would need extensive cleaning again after, before beer can be added. Maybe the mash tun? That would mean a normal mash and all the following steps. But by the time all the mash steps are done, the wort is at or near boil. Then adding dark grains back into the mash tun and adding cold water for the cold steep, the brewer would be pinned against the clock. Boil longer maybe? But then the cold steep would be very short. 30-90 minutes depending on boil. And how to time the addition of cold steeped wort into the boil kettle to ensure it is sanitized. A large-scale brewery doesn't want to lose a whole batch, which could be hundreds of gallons, compared to a homebrewer at 5-15 gallons. So, as a homebrewer consider yourself lucky to be able to inexpensively play with this process!
Ok, then what?
And of course, when all is said and done, remember the timeless words of Charlie Papazian: “Relax. Don’t worry. Have a homebrew.” If your beer doesn’t turn out quite the way you anticipated, look back, consider your variables and modify it. Experimenting with cold steep initial temperatures, total time, total volume achieved, time and volume of extract added are all in a set of variables to manipulate for the next batch…the fun is in the process and of course in a great tasting product too.
- > ABS