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Home Brew Forums > Home Brewing Beer > Brew Science > Data on amylase denaturing and starch conversion?
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Old 06-05-2009, 09:55 PM   #1
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Default Data on amylase denaturing and starch conversion?

Does anyone know of a chart that describes the time that it takes beta and alpha amylase to denature at a given temperature?

For instance, I'm looking for something like this:

Beta-Amylase
Temperature (F) 150 151 152 ...
Time to denature (min) 35 37 39 ....
etc.


In addition to the time it takes for the enzymes to be denatured, it would also be extremely helpful to know the percentage of starches that are converted to fermentable and unfermentable glucose chains for a given malt in a given period of time at a given temperature. For instance, if there was some data that said: At 10 min at 150 degrees, malt X will have converted 70% of its starches, and this conversion will consist of 67% fermentable and 33% unfermentable sugars. Does anyone know of any experiments that have documented this kind of thing?

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Old 06-12-2009, 02:17 PM   #2
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Finally found some data in "Brewing: Science and Practice."



This is pretty helpful information for formulating mash schedules. Unfortunately, it only applies to a single malt, and a non-modern one at that (as the reference is from 1947).

One interesting thing to note is that, even with a 1947 malt, mashing at 158 degrees for 30 minutes gives you nearly the same extract % and fermentability as mashing for 180 minutes. However, mashing at 149 degrees gives nearly the same extract % at 30 and 120 minutes, but the fermentability of the wort DOES increase significantly.

All of this data is in correspondence with the well-known principles of mashing, but it helps quantify these principles. The authors did not mention the specific times at which denaturation occurred, other than to mention that after 2 hours at 150 degrees, no enzyme activity was still occuring.

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Old 06-14-2009, 05:15 PM   #3
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I have done some work on this as well. It has been published here: Effects of mash parameters on fermentability and efficiency in single infusion mashing - German Brewing Techniques

And there is also an article here that summarizes the findings of that experiment and research in the literature: Starch Conversion - German Brewing Techniques

But nowhere will you find exactly what you want. For one enzymes don't denature imediately. The only thing rising temps do is to increase the rate of denaturation. I tried to explain this here: Enzymes - German Brewing Techniques. In addition to that there are other factors that affect the rate of enzyme denaturation. For beta amylase in particular there is mash thickness. But keep in mind that mash thickness also affects the rate of starch conversion.

All you will find is data from specific mash conditions that were chosen for the experiments and while you are able to draw conculsions on how various factors will affect you wort quality it is nearly impossible to determine how exactly your wort will come out. The only thing you are left with is aquiring a history of batches on your own system that shows how mash parameters affect your wort.

If you want to pay more attention to the fermemtability your worts I strongly recommend doing fast ferment tests (Fast Ferment Test - German Brewing Techniques). This test allows you to measure the fermentability w/o the affects of fermentation that could skew the results.

Kai

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Old 06-15-2009, 03:10 PM   #4
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Thanks Kai, I had read the "Effects of mash parameters.." article before, but didn't know you had written that and didn't remember that these experiments provide most of the data I am looking for. This is great work. Very helpful and interesting experiments.

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Old 06-20-2009, 12:29 AM   #5
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Check on page 111 of Michale Lewis' Brewing first edition. There's an excellent graph showing the denaturing rate of alpha and beta amylase.

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