Now the BYO wizard disagrees with me ...

Kaiser · 04-25-2008, 03:38 PM

... and the German brewing authors I read so far: http://www.byo.com/mrwizard/1391.html (2nd topic)

Most likely it was me who was spreading the word on the forum’s that a mash-out at 76 – 78 C (169 – 171 F) doesn’t kill all enzymes and is also not supposed to. I find this in all the German brewing texts that I read so far and even the ones I didn’t read say the same, according to the German homebrew forum.

The interesting thing is, that it doesn’t really matter why you believe the mash-out limit is 170F. The American literature (I have only read homebrewing stuff) seems to suggest that this limit is dure to excessive tannin extraction at higher temperatures while the German authors emphasize that enzymatic activity needs to be preserved in order to convert additional starches that are released by the lauter process. At the end, both views will have you mash-out below 170 and you will be doing the right thing.

I was just surprised to see that even some professionals disagree with what I have been saying in the recent past.

So I’ll have to make an experiment. Mash-out at 170F, hold for 15 min, take a sample of wort and add a little amount of gelatinized starch to it. Just enough to give me an iodine reaction. Keep it at the 170F temp and wait to see if any conversion is happening. This should be fairly easy to do.

Kai

**TexLaw** · 04-25-2008, 03:40 PM

There you go. The way to see what is right is to see what is right.

TL

**Nyxator** · 04-25-2008, 04:13 PM

Ever since I began homebrewing and reading different literature on the subject, I've noticed that there is a lot of conventional wisdom that seems to have scientific backing that just doesn't. I think this may be due to the level of tradition involved in the process, but there is definitely a lot a pseudoscience out there about brewing.

I read from the beginning about hot-side aeration, trub removal, the importance of secondary fermentations etc. that all have supposedly scientific explanations. In the end, we lack data.

I think this is a great idea, Kaiser, and I'm looking forward to the results. I'm on the side of the German brewers on this one, because if the American explanation were true, then a decoction mash would end in a astringent, bitter mess of a beer.

**pjj2ba** · 04-25-2008, 04:17 PM

Quote:

Originally Posted by Kaiser

[
[FONT=Verdana]The interesting thing is, that it doesn’t really matter why you believe the mash-out limit is 170F. The American literature (I have only read homebrewing stuff) seems to suggest that this limit is dure to excessive tannin extraction at higher temperatures while the German authors emphasize that enzymatic activity needs to be preserved in order to convert additional starches that are released by the lauter process. At the end, both views will have you mash-out below 170 and you will be doing the right thing
So I’ll have to make an experiment. Mash-out at 170F, hold for 15 min, take a sample of wort and add a little amount of gelatinized starch to it. Just enough to give me an iodine reaction. Keep it at the 170F temp and wait to see if any conversion is happening. This should be fairly easy to do.

Kai

I've always wondered about the 170 F limit and the supposed tannin release. If this is indeed a problem, then why aren't decocted beers loaded with tannins? Heck, they're boiled, not kept at 170 F. Does not compute.

As to the experiment, an even quicker and easier way to get a handle is to use salivary amylase. Then you could do the experiment while doing some drinking and kicking back. It won't be as stable, but it may give you and idea,

I'm off to lunch, I'll post some refs. latter. I just found one ref. refering to different isoforms of beta-amylase (that vary in their abundance with the barley variety) and differences in their thermostability. The wimpiest form craps out in 5 min. at 60C, while the most robust is at 20% activity at 15 min. and down to 5% at 20 min.

**olllllo** · 04-25-2008, 04:23 PM

I'm interested to see what HBT's Der Hexenmeister has to say!

menschmaschine · 04-25-2008, 05:11 PM

Very interesting Kaiser. This is the part of brewing that I love... hypotheses and scientific experiments. Looking forward to your results. I'm rooting for the Germans... you know, because mein Name ist Menschmaschine!

brewt00l · 04-25-2008, 06:21 PM

Quote:

Originally Posted by menschmaschine

This is the part of brewing that I love... hypotheses and scientific experiments.

...and here I would have guessed it was the drinking really good beer part!

Kaiser · 04-25-2008, 06:36 PM

Quote:

Originally Posted by menschmaschine

I'm rooting for the Germans... you know, because mein Name ist Menschmaschine!

Carful here. I don't want this to be seen as a fight to see who is correct. I waould actually be more intested where the 2 different views are coming from.

Quote:

...and here I would have guessed it was the drinking really good beer part!

+1

Kai

NitrouStang96 · 04-25-2008, 06:43 PM

Great idea!

ClutchDude · 04-25-2008, 07:02 PM

I've been wondering why you don't see more tannin extraction at that point. It's higher phs & temperature that leads to it, i've been told.

Anyways,

Science!