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menschmaschine · 11-08-2008, 02:50 PM

Quote:

Originally Posted by Piotr

I heard different explanation - in thick mash b-amylase survives longer, so it can longer do the starch-cutting job.

That's true, but I take it to more apply to a Protein rest (or acid rest). In other words, if you're doing a Protein rest, a thick mash will help more heat-labile enzymes to "survive" into the saccharification rest. This also explains why it's good (when doing a Protein rest) to start thick and gradually thin the mash as you increase rest temps for a more attenuable wort.

But in general, a thinner mash increases the proportion of maltose (to dextrins) and gives a higher attenuation potential.

Piotr · 11-08-2008, 03:16 PM

Quote:

Originally Posted by menschmaschine

That's true, but I take it to more apply to a Protein rest (or acid rest). In other words, if you're doing a Protein rest, a thick mash will help more heat-labile enzymes to "survive" into the saccharification rest.

It is a shame that I can't find any data about the lenght of life of enzymes in varius temperatures. The only information is that drawing, I've found in a brewing book: (s**t, I don't know how to attach pictures here...)

Anyway, it says in 45*-50*C b-amylase lives forever, in 57*C ~2 hours, in 63C - 1 hour, in 70*C - 3-5 min (all that in a very thin mash).

So the protein-rest temperatures are no danger for enzymes.

**Mustangj** · 11-08-2008, 03:18 PM

Cool Video!!

New to all grain brewing.

I thought it was a bad idea to boil grains?

menschmaschine · 11-08-2008, 03:26 PM

Quote:

Originally Posted by Piotr

It is a shame that I can't find any data about the lenght of life of enzymes in varius temperatures. The only information is that drawing, I've found in a brewing book: (s**t, I don't know how to attach pictures here...)

Anyway, it says in 45*-50*C b-amylase lives forever, in 57*C ~2 hours, in 63C - 1 hour, in 70*C - 3-5 min (all that in a very thin mash).

So the protein-rest temperatures are no danger for enzymes.

There's another thread about this on here and John Palmer (How To Brew) describes it best:

Quote:

The grist/water ratio is another factor influencing the performance of the mash. A thinner mash of >2 quarts of water per pound of grain dilutes the relative concentration of the enzymes, slowing the conversion, but ultimately leads to a more fermentable mash because the enzymes are not inhibited by a high concentration of sugars. A stiff mash of <1.25 quarts of water per pound is better for protein breakdown, and results in a faster overall starch conversion, but the resultant sugars are less fermentable and will result in a sweeter, maltier beer. A thicker mash is more gentle to the enzymes because of the lower heat capacity of grain compared to water. A thick mash is better for multirest mashes because the enzymes are not denatured as quickly by a rise in temperature.

TeleTwanger · 11-08-2008, 03:54 PM

+1 on thinner mashes...I used to do 1qt/lbs but man that is more trouble than it's worth! Now I do around 1.6qts/lbs and I get great conversion (85% efficiency) and even without mash-out lautering is never a problem.

zoebisch01 · 11-08-2008, 04:39 PM

Hey thanks so much for this Kaiser! Mods, can you make this a sticky?

menschmaschine · 11-08-2008, 04:42 PM

Quote:

Originally Posted by Mustangj

Cool Video!!

New to all grain brewing.

I thought it was a bad idea to boil grains?

This has been talked about a lot. It's fine to boil grains in a decoction. Greg Noonan says:

Quote:

...because the density and pH of the decoction prevents phenols from being leached out of the husks.

So, you won't extract tannins like you would if you got a lot of grains in your boil after sparging.

**Mustangj** · 11-08-2008, 05:14 PM

thanks for the info.

Unfortinaly Boiling and grains come up a lot when doing a search.

TeleTwanger · 11-08-2008, 05:26 PM

Quote:

Originally Posted by Mustangj

thanks for the info.

Unfortinaly Boiling and grains come up a lot when doing a search.

Also as explained in the video, by boiling a thick decoction (mostly grain) after the mash sits long enough to disolve most of the enzymes the enzymes are not denatured, they are left in solution in the un-boiled liquor.

korndog · 11-08-2008, 11:28 PM

Today's brew. This is how I do a decoction. First I find a friend who is willing to stir the decoction...........hehe........nice vids kai.