Brewing Dunkelweizen

Brewing the Dunkelweizen went well on Monday, although it did seem to take us quite a long time. We started at 4pm as we usually do, but it was after 10pm when we were finished and cleaned up. This was partly due to the 90 minute boil and partly, I think, due to the masses of different malts that each had to be weighed out.
When we brew an English ale we boil the wort for 60 minutes. This achieves the following:

• It extracts the bittering oils from the hops;
• It sterilises the wort – malt is covered in bacteria so if you didn’t sterilise it the yeast would have a hell of a fight on their hands;
• It develops some of the richer “cooked” flavours - the melanoidins from the Maillard reaction: same as when you cook food (imagine microwaving a steak rather than frying and you’ll get the idea).

So why a 90 minute boil for Dunkelweizen? Well the recipe uses some pilsner malt, which is very lightly kilned. These lightly kilned malts contain DMS (dimethyl sulfide), which can give the beer the taste and aroma of canned sweetcorn. You need a longer boil time to be sure to drive it all off, apparently.
And as for weighing out all those malts, well the photo speaks for itself:

Dunkelweizen needs to be fermented a little cooler than an English ale – ideally 17C. So it’s currently in the under stairs cupboard sputtering yeast all over the place!