Reverse Mash Infusion Temps

[TheCrowsNest]

I've only done mashes with progressively higher temps. Does anyone know what the effects are of starting a mash at 155*F and letting it drop to something like 149*F are?

Let's assume I use an IC and some stirring to drop the temp over the course of a few minutes. Will beta-amylase enzymes do work after they grains have been heated above the ideal range? What would the effects be?

 

[Jakemo]

The majority of conversion takes place in the first 10-15 minutes, so there's that. Otherwise, it is kind of an interesting question...

 

[dcp27]

depends how long its up there. the beta enzymes aren't immediately denatured, but do over time, so in theory lowering the temp would keep them around a bit longer. if its too long you're basically just slowing down the work of the alpha enzymes.

 

[Denny]

The first question is why...what do you hope to accomplish by doing this? Think that through.

You have about 20 min. before the enzymes are denatured.

 

[TheCrowsNest]

I'm not looking to accomplish anything. Just curious about the effects. That 20 minute time-frame answers my question though. Thanks!

 

[BBL_Brewer]

What sucks about the whole thing is that you need alpha to break up the larger amylopectins so that beta can create more maltose. When doing step mashes, you favor beta first (since is has a lower temp threshold) and then favor alpha. Seems kind of backwards, but I suppose the enzymes are still active to a certain degree outside theier respective temp ranges and the whole thing works out in the long run.

 

[TheCrowsNest]

What sucks about the whole thing is that you need alpha to break up the larger amylopectins so that beta can create more maltose. When doing step mashes, you favor beta first (since is has a lower temp threshold) and then favor alpha. Seems kind of backwards, but I suppose the enzymes are still active to a certain degree outside theier respective temp ranges and the whole thing works out in the long run.

That's what got me thinking. I guess it's best to refer to the old adage: if it ain't broke, don't fix it.

 

[Denny]

What sucks about the whole thing is that you need alpha to break up the larger amylopectins so that beta can create more maltose. When doing step mashes, you favor beta first (since is has a lower temp threshold) and then favor alpha. Seems kind of backwards, but I suppose the enzymes are still active to a certain degree outside theier respective temp ranges and the whole thing works out in the long run.

Here's a chart from How to Brew that shows temp ranges fro various enzymes. Note the overlap...

​

 

[Ryush806]

I've accidentally done this before actually. I'm really not sure what was different that time...same cooler MLT covered with the same quilt, same calibrated thermometer, similar grain weight, same water/grist ratio. I mashed in at 154 and it fell to 145 over an hour. Of course the one time I didn't check the temps it did this. Usually I only lose 2 deg/hr. Anyway, I got normal efficiency for my set up and didn't have any trouble lautering. The only difference I could really tell is that my wort was slightly more fermentable. It finished about 4 points lower than I expected. Still turned out great though!