I'm going to try this: "Dough-in at 111° F (44° C) and hold for 15 minutes. Ramp up to 131° F (55° C), and rest 10 minutes. Pull thick decoction and slowly heat to 158° F (70° C), and rest 20 minutes. Boil 10 minutes, stirring constantly. Meanwhile, ramp main mash up to 149° F (65° C) and hold. Recombine, and equalize at 158° F (70° C). Rest for 10 minutes. Mash out at 170° F" from Gordon Strong's El Hefe, though my hops will be different. No that that matters on this topic. The question I am trying to wrap my head around is this; Does the decoction boil stop conversion from being possible for that portion of the mash after it has been recombined with the mash that is (in this instance) at 149 and raising to 158? To expound on what is confusing me, does the grain get decocted and then it's only purpose in life is to raise the temp of my remaining mash, or does it come down from it's boiling temp and begin a second life of conversion?
By pulling mostly all grains (thick decoction), you should be leaving behind a lot of their enzymes in the mash. Holding it at 158 will allow some enzymatic processes to occur, but boiling will explode the starches and and then they don't need any further enzymatic work in the mash. So basically, after you pull and boil the decoction it is done. The way I've always seen it is that decoctions are done to raise temperature without watering down the wort (and it helps add body to the beer).
So, isn't this going to lower my OG since the amount pullled to decoct won't be sacchrifying? <--not sure that's a word.
using = usually? Ok, so if that's true then it doesn't stop completely, it stops and then continues back in the mash. Right?
The majority of the enzymes are in the liquid. Boiling makes more of the small starch granules available to the enzymes when they are put back into the main mash. So you convert more starch to sugar and the efficiency goes up a little. I see a couple gravity points more when I do a decoction. A 1.048 goes to 1.050 or so.
Thank's Jeff. Some reason you made it click for me! I was confusing enzymes in the mash as in the GRAIN and not in the mashing WORT.
Um, improvise, adapt, overcome? So far I have only had to adjust emp by adding cold water to my mash tun.
That's my understanding as well. The enzymes in the decoction will be deactivated, but the boling will explode the kernals and make more starches available for conversion as the decoction is returned to the main mash. So you usually get higher efficiency than a single infusion. I did the El Heffe recipe a couple months ago, btw. The best heffe I've ever had, if I do say so meself!
Well, the decoction will denature some enzymes, but the enzymes left in the non-decocted part of the mash will be enough to make up for it, assuming you already had diastatic power overkill, which you generally do with the types of grists you're likely to decoct.
Decoctions actually work well with malts with low modification and/or diastatic power. This is what they used in the olden days. A tripple decoction would take the grain through the sacrification temps many times, so you could get conversion. It also worked for the brewers in Pilsen, where the Ca levels are low, as they would start with an acid rest.
I have only decocted once (boiled enough grain to reach mashout temp) and I think to date it has had the highest efficiency of any beer I have brewed. I was nervous to try it but wound up having a lot of fun with it too.
