Author Topic: Dextrin Malt-not subject to enzyme degredation?  (Read 659 times)

Offline davisdandrew

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Dextrin Malt-not subject to enzyme degredation?
« on: February 21, 2011, 12:13:48 PM »
I have a question about dextrin malts that's been nagging at me for a while. Dextrin malts are generally advertised as having the capacity to improve body, mouth-feel, palate fullness, and foam stability due to dextrins created during the malting process.  So, it would seem to me that these dextrins would be subject to enzymatic degradation in the mash. After all, unless they are limit dextrins, which would not be subject to further a-amylase or b-amylase activity, the dextrins contributed by the dextrin malt would just be one step closer to complete conversion than starch from the base malt. What is going on here?

 

Offline tschmidlin

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Re: Dextrin Malt-not subject to enzyme degredation?
« Reply #1 on: February 21, 2011, 12:43:06 PM »
Hilarious, the same wording of this post is here and here from years ago . . .

Here is an answer:
http://www.brewingtechniques.com/library/backissues/issue2.3/miller.html
Quote
Basically, the malting conditions are so manipulated that the sugars and dextrins are changed into nonfermentable isomers that also cannot be attacked by the malt enzymes, alpha and beta amylase. This means that, no matter how long the dextrin malt sits in a mash tun, little or no breakdown will occur. In addition, virtually all of the carbohydrates extracted from dextrin malt are unfermentable. These characteristics make dextrin malt an almost ideal "body builder" for beers.

In my own words, α and β amylase are able to break α1-4 bonds between the glucose molecules.  Based on what Dave wrote above, I'd guess that most of the α1-4 bonds are converted to β1-4 bonds, which cannot be broken by the enzymes.
Tom Schmidlin