Help with experiment RE: dextrin rest time - Home Brew Forums
Register Now For Free!

Home Brew Forums > Home Brewing Beer > Brew Science > Help with experiment RE: dextrin rest time

Reply
 
Thread Tools
Old 02-26-2010, 04:27 PM   #1
SpanishCastleAle
 
SpanishCastleAle's Avatar
Recipes 
 
Jan 2009
Central Florida
Posts: 4,345
Liked 36 Times on 36 Posts



In the Hockhurz section of Kaiser's Decoction Mashing article he states:
Quote:
To reduce and eventually terminate the beta amylase activity and to ensure that all starch in the wort has been converted (especially the small starch granules which have a higher gelatinization temperature), a dextrinization rest is held at 158 - 162 *F (70 - 72 *C). At this temperature the beta amylase is quickly deactivated and only the alpha amylase works on the starches. The rest is held until the mash is iodine negative (no starch or long dextrines in the wort). Narziss [Narziss, 2005] and Fix [Fix, 1999] suggest, that a rest at 158 - 162 *F (70 - 72 *C) benefits head retention and body of the beer through glycoproteides that are extracted from the malt but not degraded by enzymatic activity. Because of that Narziss suggests holding this rest up to 60 min. After that rest a mash-out is performed at 167-173F (75-78 C).
I would like to do an experiment to test this. I was hoping to make one mash (for a ~10.5 gal final volume) and then ferment in two identical 5 gal carboys. I was thinking of doing the Hockhurz Infusion mash and pulling the wort for the 'short dextrin rest' (SDR) batch after only 10 minutes @ 161* F and then letting the remaining wort sit for another full hour for the 'long dextrin rest' (LDR) batch. So it looks like a no-sparge lauter. But how would I do the mash-out for each and make it as controlled as possible? Anything else I'm missing?

Also, RE: the glycoproteides mentrioned above; does this mean that it would be better to use a base malt with more protein for this experiment? Cont. Pils instead of UK Pale? That's pretty much all I got on hand for base malts (plus Munich).

Any help appreciated.
__________________
Early brewers were primarily women, mostly because it was deemed a woman's job. Mesopotamian men, of some 3,800 years ago, were obviously complete assclowns and had yet to realize the pleasure of brewing beer.- Beer Advocate

 
Reply With Quote
Old 02-26-2010, 04:54 PM   #2
pjj2ba
Look under the recliner
HBT_LIFETIMESUPPORTER.png
 
pjj2ba's Avatar
Recipes 
 
Jul 2006
State College, Pennsylvania
Posts: 3,379
Liked 206 Times on 167 Posts


I don't have a thought on the experiment - yet - just some more background information.

Most of the glycoproteins found in plants are typically associated with some kind of membrane, and are more difficult to extract. Both in a lab setting and in beer making. They stay stuck to the membrane fractions (and are somewhat protected from proteases). In the lab, we can use high salt and/or detergents to release them, both brewing no no's. The prolonged high temp. might just loosen them up. This is not something one would try in a lab, as heat is normally a proteins enemy. In the case of brewing though we are not looking to isolate intact and active proteins.

Hmmmm.....maybe it is time again to work on my Moustache Ride Pale Ale (shooting for a beer that gives a lasting foam moustache - get your minds out of the gutter)
__________________
On Tap: Doppelbock O'fest, Pale Ale, cider
Kegged and Aging/Lagering: CAP, Ger. Pils, OKZ (std Amer. lager), CZ Pils, Amer. Wheat, Rye IPA, Saison
Secondary:
Primary: Ger Pils, CAP
Brewing soon: Pale lager, Amer. wheat
Recently kicked : (
Pilsner Urquell Master Homebrewer
(1st NYC 2011, 2nd NYC 2012)
P U crowns winners in its inaugural master HB competition

 
Reply With Quote
Old 02-26-2010, 05:12 PM   #3
SpanishCastleAle
 
SpanishCastleAle's Avatar
Recipes 
 
Jan 2009
Central Florida
Posts: 4,345
Liked 36 Times on 36 Posts


Quote:
...get your minds out of the gutter
It def was from the name!
__________________
Early brewers were primarily women, mostly because it was deemed a woman's job. Mesopotamian men, of some 3,800 years ago, were obviously complete assclowns and had yet to realize the pleasure of brewing beer.- Beer Advocate

 
Reply With Quote
Old 02-26-2010, 09:44 PM   #4
menschmaschine
 
menschmaschine's Avatar
Recipes 
 
Jun 2007
Delaware
Posts: 3,272
Liked 41 Times on 33 Posts


Just some initial thoughts regarding the mashout...

The main concern here is to stop enzyme activity. You can achieve that by having the heat on in the first boil kettle as the wort drains into it. That will stop enzyme activity pretty quickly as the wort goes in and the temp goes up. For the second "batch", you could go ahead and do the mash out because you don't need to be concerned with preserving the enzymes in the mash.
__________________
END TRANSMISSION

 
Reply With Quote
Reply
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Is it time for my bock to rest? rich8932 General Techniques 4 02-11-2010 03:17 AM
Is this the right time for my Diacetyl rest? kingoslo Beginners Beer Brewing Forum 7 10-21-2009 04:06 PM
GaP experiment. first time flop Arneba28 Recipes/Ingredients 16 06-20-2008 06:19 PM
Lager rest time Reverend JC General Techniques 6 12-18-2006 12:22 PM
time for protein rest in cooler tun Beerdoc All Grain & Partial Mash Brewing 8 03-05-2006 07:40 PM


Forum Jump