Decoction mash paradox ?

[KYT]

I was listening to a Brew Strong episode the other night, and the guys were talking about decoction mashing.
I was under the impression that the decoction method used the liquid, but they were saying you boil the grain pulled from the mash.
Another impression I was under, was that we lauter to separate the mash from the grain to boil.
So if you're going to pull grain to boil a number of times for up to an hour or more each time, how is that different than leaving the spent grain in the boil kettle?

I'm not interested in doing decoctions, it's just something that occurred to me.

[BDawg]

When you pull the thick part of the mash (the grain part) and boil it you are leaving most of the liquid behind, so generally the pH won't go up (even though the temp does) and the lack of water won't leach tannins into the wort, so the action is more like "cooking" the grist than "boiling" it. In a sense, the tannins kind of stay put, because there is no place for them to really go (think of particle equalization/dispersion across a membrane).

Leaving the spent grains in the boil allows a large volume of water to contact the husk at all times. This coupled with the long heat causes the tannins to come out causing astringency.
High pH also causes the same effect.

HTH-

[Kbar]

https://byo.com/bock/item/537-decoction ... techniques

[Dirk McLargeHuge]

I really hate decoction mashes. SGTSatan loves them, and when I brew with him, he does triple decocotion brews just to piss me off!

[KYT]

When you pull the thick part of the mash (the grain part) and boil it you are leaving most of the liquid behind, so generally the pH won't go up (even though the temp does) and the lack of water won't leach tannins into the wort, so the action is more like "cooking" the grist than "boiling" it. In a sense, the tannins kind of stay put, because there is no place for them to really go (think of particle equalization/dispersion across a membrane).

Leaving the spent grains in the boil allows a large volume of water to contact the husk at all times. This coupled with the long heat causes the tannins to come out causing astringency.
High pH also causes the same effect.

HTH-

Ah ok that makes sense.

[speed]

I really hate decoction mashes. SGTSatan loves them, and when I brew with him, he does triple decocotion brews just to piss me off!

i did a triple decoction doppelbock a few years back, the beer turned out GREAT but i don't know if i want to go through that again.