Well, traditionally it was done to raise the mash temp in step-mashes. The maillard reaction is a happy by-product. I do it for the subtle change in flavor this produces.
However, this is argued back and forth as to whether it (decoction) really does much at all for the flavor and is probably unnecessary. I believe it does have an effect.
I agree with Euge. Not “necessary” in a strict sense, but it will make a better product, if done properly. I use decoction mashes on any beer that will have a low hop presence, where I want a strong and nuanced malt character. It is also a good way to hit multi-step temps without throwing your grain/grist ratio way off.
This is why I’ve recently started to play around with decoctions. I don’t have enough experience with it yet to make a judgment on how it affects the flavor profile but it seems to be an effective way of moving between step temperatures.
Necessary? No. Beneficial? IMHO, Yes. I do a single decoction in my German wheat beers. I like the character. Can’t really put my finger on it, but they always seem to score better in competition. My gold medal hefe two years ago was decocted (and really, really fresh).
I’m assuming by late you mean a thin decoction for mashout. No, I do it in the middle. I do a short protein rest, then ramp it up to low saccharification temps, pull the decoction and remix to hit high sacc temps. Then ramp for a mashout. The full recipe was published in Zymurgy, and it will be in my book.
Ah, a typical author, always looking to plug their book ;) Actually, I’m really looking forward to it and will be putting in my pre-order next week. Getting back to the thread, Is the protein rest really beneficial with today’s malts? I ask this in general as well as specifically for wheat beers.
I usually do 10-15 min at 131F/55C when I use continental malts or starchy adjuncts. My hefe is usually just Durst wheat and pils. I almost never to rests at 122F/50C.
I get better clarity when I do this, but that’s not really an issue with this style. Again, I’ve done it this way for a long time and it doesn’t cause problems. I’ve tried my recipe with just a straight single infusion but I don’t like it as much and it doesn’t seem to score as well. Not really sure why; I think it’s something with the mouthfeel.
I do just a single and when I do, I’ve been using Jeff Renner’s method from a couple months back issue of Zymurgy that uses my pressure canner - no constant stirring required
I do a double, but I think the critical factor is to do at least one decoction prior to conversion. The single post-conversion decoction doesn’t have near the effect, IMO.
Not impossible, you just might have to also infuse some water. That is, mash in somewhat thick, draw off and decoct a portion, and then, when you add the decotion back to the main mash also add as much boiling water as necessary to hit the next rest. By mashing in thick, once you add the infusion water, you can still keep your water/grist ratio from getting too high.