Some brewers will notice a bitter or astringent aftertaste in their stouts, and that can be caused by including the dark malt into the mash. Cold steeping dark malts is a great way to get the most out of your dark malts. It’s a technique that is used to extract the most aroma and flavour without extracting tannins. If you try this technique, you will definitely notice a difference.
Cold steeping is pretty straight forward.
- Simply put about 2-3 liters of water into a bowl. I use a stainless steel mixing bowl because I like how the plastic wrap makes a good seal around the bowl.
- Crush your dark malt as you normally would.
- Put the dark malt into the bowl of water and cover with plastic wrap. I also put aluminum foil over it to create a better seal (probably not necessary).
- Steep the dark malt in the water at room temperature for 24 hours.
- Use a mesh strainer to filter out the malt. You will be left with a dark malt extract.
- Add the extract to the boil at the 30 minute mark.
Some will advise to add the dark malt extract at the 10 minute mark or even at flame-out in order to ensure a smoother flavour and less astringency, but I don’t recommend that. Tannins are not soluble at room temperatures, so by cold steeping the dark malts, you’re already doing the best thing to ensure that the tannins are not extracted from the grain husks. I think that ensuring that you sterilize the extract is much more important, and I wouldn’t risk an infection.