Mash Temp Dropping, Conversion Question

[cfhomebrew]

I do single infusion mashing in a cooler. If I mash in at 154 degrees and over the course of 60 minutes the temperature drops to 148, am I also reaping the benefits of mashing at 148, or does that conversion not happen since the mash spent time at a higher temperature?
Thanks.

 

[GreenCheek]

I'm under the impression that when you start at a high mash temp and go lower the grain is no longer capable of benefiting from the lower temperature rests. This is why breweries step up rather than down to really capitalize over rest temperatures. This being said, your high temp isn't high enough to create your unfermentable dextrines (155+) with all grains, so you'll still have a decent amount of fermentable sugars.

I'm sure i butchered the whole explanation & there's folks here that can go into more detail from memory because i'm referencing a book & can't find the page where it's explained well. I'm attaching a chart that shows the progress of fermentable sugars as the temperature rises. Once you go over a certain point, the grain is no longer capable of the lower temp enzyme activity.

 

[Kent88]

Check this out. Then part 2, here.

The Brewing Network has some decent info. Without listening back today, I'd guess that while you're in the mid 150F range that beta sacch' is happening a bit faster than it would be at a temperature that would be a bit more stable for that enzyme, and that the beta enzyme isn't doing as much as it would be if your temp immediately stabilized at 149F. Once that denatures you're probably just getting a little more conversion happening from the alpha enzyme, so really you should probably add a small infusion at about 40 minutes to bump the temp back up to alpha zone.

 

[cfhomebrew]

Thanks much for the info guys I will definitely listen to those podcasts.

 

[theowlman16]

Why not add a small amount of 170 (or so) water mid mash? What are you using for your mash tun? A lot of us cover it with a blanket/jacket/insulation of some kind to keep the heat stable.

 

[wilserbrewer]

6 degree loss in a cooler seems excessive. Are you preheating the cooler?

Ime best practice to add strike water 10-15 degrees hot and let it settle to strike temp also effectively pre heating the cooler.

 

[RM-MN]

I do single infusion mashing in a cooler. If I mash in at 154 degrees and over the course of 60 minutes the temperature drops to 148, am I also reaping the benefits of mashing at 148, or does that conversion not happen since the mash spent time at a higher temperature?
Thanks.

It depends. It depends mostly on the milling of the grain. Conversion starts when the starches are gelatinized so the enzymes are able to do the conversion. With grains that are milled well (as fine as your system will tolerate) the starches will gelatinize quickly and conversion is very quick but when you have larger grain particles it takes much longer to gelatinize the starches so if the temperature falls during that time, you get more of the activity of the beta amylase and that portion of the mash is effectively done at the lower temp. With very poorly milled grains you might still be waiting for full gelatinization at an hour. If you stop the mash then your efficiency will be low but you might be able to compensate with a longer mash....provided the temperature does not fall below where the enzymes are active.

 

[cfhomebrew]

Thanks again everyone, they example I gave was on the extreme side - I have basically eliminated this problem by pre-heating the cooler and using blankets. I was kind of wondering if I could do this heat drop intentionally to achieve a step-type mash in reverse (going down in temp) since it is a difficult for me to do a normal step mash (temp rising) in the cooler. I have have had some success by adding more hot water to raise the temp I am somewhat limited by the size of the cooler. I never would have thought about the crush coming into play here - very interesting RM-MN.