Decoction Mashing Questions.

[Orangevango]

Is there anything wrong with doing a Decoction Mash on a style where it is not comonplace, specifically a Barleywine? I ask because Im looking to increase the batch to batch consistancy I get when using home-malted barley which has less than ideal modification. I also am planning on toasting my base malt which is suposed to decrease enzymes. So will using Decoction on a barleywine contribute undesirable flavors for the style?

One thing I dont get is how a Decoction makes up for the lack of enzymes in poorly modified grains. Doesnt boiling a portion of the mash denature some of its enzymes? Any brew-chemists out there who could clear that up for me?

Does it convert the sugars without the use of enzymes, similar to a cereal mash?

 

[menschmaschine]

Is there anything wrong with doing a Decoction Mash on a style where it is not comonplace, specifically a Barleywine? I ask because Im looking to increase the batch to batch consistancy I get when using home-malted barley which has less than ideal modification. I also am planning on toasting my base malt which is suposed to decrease enzymes. So will using Decoction on a barleywine contribute undesirable flavors for the style?

It really depends on the grain you use and has more to do with rest temperatures than the act of decocting. For instance, you wouldn't want to do any rest (other than an acid rest) below ~149°F with Marris Otter or other British Pale malts. For pilsener malt or Am. 2-row, you can do protein-related rests, but with most of today's malts, it's best to keep these rests above 130°F.

One thing I dont get is how a Decoction makes up for the lack of enzymes in poorly modified grains. Doesnt boiling a portion of the mash denature some of its enzymes? Any brew-chemists out there who could clear that up for me?

Does it convert the sugars without the use of enzymes, similar to a cereal mash?

Decocting doesn't necessarily make more enzymes, but it makes the most of the enzymes that are there. The main mash is the preservative of enzymes. These enzymes are solubilized shortly after dough-in. This is why you pull a thick decoction on all but the mash out decoction... you're leaving most of the enzymes behind in the main mash. After pulling the decoction, you heat the decoction up to a rest in the upper 150s°F for about 10 minutes before heating to boiling. This rest allows alpha-amylase to break down some of the long chain sugars. When returned to the main mash, beta-amylase can break these down further into simpler sugars such as maltose. Beta amylase wouldn't be able to break down these complex sugars otherwise.

Also accomplished in the decoction, is when heating above about 170°F, grain particles that would stay intact in a normal mash, burst open and make more starches and complex sugars available for the enzymes to break down in the main mash.