General Category > All Grain Brewing

Alpha Amylase conversion post mash

<< < (3/3)

ynotbrusum:

--- Quote from: narvin on August 05, 2013, 03:28:32 PM ---
Isn't this a classic step mash?  145 for 40 minutes, 158 for 30.

Or do you mean the second step is in the kettle?  Again, I don't know how many of the unconverted starches carry over.  I know a turbid lambic mash uses hot sparge water (200+) to dissolve as much of this starch as possible, since it's desirable for lambic fermentation.

--- End quote ---

Yea, I meant the second step being in the kettle - just may try it as an experiment, but not likely a standard operating procedure for the future.

denny:

--- Quote from: ynotbrusum on August 05, 2013, 06:43:46 PM ---
--- Quote from: narvin on August 05, 2013, 03:28:32 PM ---
Isn't this a classic step mash?  145 for 40 minutes, 158 for 30.

Or do you mean the second step is in the kettle?  Again, I don't know how many of the unconverted starches carry over.  I know a turbid lambic mash uses hot sparge water (200+) to dissolve as much of this starch as possible, since it's desirable for lambic fermentation.

--- End quote ---

Yea, I meant the second step being in the kettle - just may try it as an experiment, but not likely a standard operating procedure for the future.

--- End quote ---

I think the rub might be trying to hold 158ish in the kettle.  Less mass than the mash, so it seems like it would be more difficult to achieve a stable temp.

hopfenundmalz:
Mash out denatures the Beta. The alpha is still active.
http://jrhb.org/docs/Enzymes-2010-05.pdf

drjones:

--- Quote ---Yea, I meant the second step being in the kettle - just may try it as an experiment, but not likely a standard operating procedure for the future.
--- End quote ---
So the idea is to drain off via a batch sparge a bit early so you can bring the temp back up in the kettle?
I don't see any problem with this - depending on your recipe, there may actually be hardly any starch left to convert anyway (as some have noted), but conversion will continue until either the starch is spent or the enzymes have denatured.  I think if your'e careful, you can hold a roughly 158 degree temp for long enough, but it is easy to overshoot on the way up, so I'd cut the heat a bit early.

For the record, I recently ran a constant 160 degree mash in an attempt to get a more full-bodied (dextrinous) session IPA.  It seems to have worked quite well - with a 1.046 OG finishing at 1.015 (3.9% ABV).  Both beta and alpha amylase are active at this temp - for a while.  The beta can't hold out long, but while it's working, it is working hard.  I clearly had plenty of fermentable sugars in the final mix.   (The "scary high" mash was inspired by the Lagunitas IPA recipe - of course I could have just used dextrine malt or maltodextrine, but I wanted to try to achieve this through the mash process itself).  In short, if you do overshoot 158 by a bit, it probably won't be the end of the world - and in your case, the beta amylase has already done its work, anyway.

bluesman:
The conversion of starches to sugar is dependent upon the enzymes accessibility to the starches, which in a fluid state, it's very likely that most enzymatic conversion will occur within the first 20 minutes of the mash. Then whatever is left will eventually be converted during the rise in temp to mashout or sparge. Raisng the temp to 158F, will in essence, convert any residual unconverted starches via alpha amylase, which is probably a very small percentage of the converted starches at that point during the mash.

Navigation

[0] Message Index

[*] Previous page

Go to full version