HBearBrew
Member
I have always wanted to try the cold steep method for dark and specialty while brewing a stout, but the lack of literature on extract efficiency with cold steep somehow always stopped me. I was especially interested as cold steeping would enable me to lower the amount of grain in my main grist, which would ease my mash and boost my efficiency. I wanted to cold steep because all the well-researched advantages in terms of flavors being less astringent, but at the same time also make sure to extract enough sugars out it it so I don't just get color and flavors, and none of the unfermentable sugars needed to give body to my stout.
While everyone agrees cold steep is less efficient, I have struggled to find any agreement or data out there. Advice go from increase by 10% to increase 3 fold in order to reach similar extraction with simply mashing my dark with the rest of the grains. So I recorded my data and I am sharing it for whoever is interested.
I had planned on using 0.4kg chocolate, 0.3kg roasted barley and 0.3kg special B. Not knowing where to start I decided to double these quantities. So 0.8kg chocolate, 0.6kg roasted barley and 0.6kg special B, with a mash thickness of 5 L/kg (2kgs total in 10L water) - that is, 2.6 quarts of water per pound of grains.
I went for a 24h room temperature mash, BIAB no sparge - so no need to discuss how my sparge could have or not affect the results I collected 9 Liters at 1.035.
Using Palmer's book, I calculated that the maximum extraction for my cold steep would have been 62.6 [using PKL, (284x(0.8/9)+300x(0.6/9)+261x(0.6/9)]. I have therefore obtained a cold steep efficiency of 56%.
This means that when planning to use cold steep with dark grains when extracting sugars matter, at a wort volume to grain ratio of 5L/kg (2.6qt/lbs), the expected efficiency is closer to 50%. In other words, using 1.5x the amount compared to the amount you planned for hot mashing would bring you in the same range. A mash at any other water to grist ratio would yield a different result of course, that's why I am making sure to indicate the ratio I used.
I then proceeded on topping this dark wort with water to my desired mash volume and went for an overnight mash with the rest of the grains.
To the million dollars question -- how does the final stout taste -- I'll post the result here in few weeks, and the full recipe if it turned out good
While everyone agrees cold steep is less efficient, I have struggled to find any agreement or data out there. Advice go from increase by 10% to increase 3 fold in order to reach similar extraction with simply mashing my dark with the rest of the grains. So I recorded my data and I am sharing it for whoever is interested.
I had planned on using 0.4kg chocolate, 0.3kg roasted barley and 0.3kg special B. Not knowing where to start I decided to double these quantities. So 0.8kg chocolate, 0.6kg roasted barley and 0.6kg special B, with a mash thickness of 5 L/kg (2kgs total in 10L water) - that is, 2.6 quarts of water per pound of grains.
I went for a 24h room temperature mash, BIAB no sparge - so no need to discuss how my sparge could have or not affect the results I collected 9 Liters at 1.035.
Using Palmer's book, I calculated that the maximum extraction for my cold steep would have been 62.6 [using PKL, (284x(0.8/9)+300x(0.6/9)+261x(0.6/9)]. I have therefore obtained a cold steep efficiency of 56%.
This means that when planning to use cold steep with dark grains when extracting sugars matter, at a wort volume to grain ratio of 5L/kg (2.6qt/lbs), the expected efficiency is closer to 50%. In other words, using 1.5x the amount compared to the amount you planned for hot mashing would bring you in the same range. A mash at any other water to grist ratio would yield a different result of course, that's why I am making sure to indicate the ratio I used.
I then proceeded on topping this dark wort with water to my desired mash volume and went for an overnight mash with the rest of the grains.
To the million dollars question -- how does the final stout taste -- I'll post the result here in few weeks, and the full recipe if it turned out good