What actually happens when mash temp decreases?

[Beer is good]

I notice all mashing schedules only increase, I believe this is to kill off enzymes in order.

My question is if I start a mash at 150 and it dwindles down to 140 over an hour, what happens? Is the conversion still happening? How much of a problem is this?

Thank you

 

[BigRob]

You might notice your wort is slightly more fermentable, but in general conversion happens pretty quickly with modern malts, it's why your strike temps are fairly important in a lot of recipes. I don't believe they're denatured/killed off until they hit 170F or thereabouts, just less active at a temp outside the optimal range.

 

[grathan]

good question. supposedly the beta enzymes chew up the alpha's work and make a highly fermentable wort. I think it would take brewing of 5 years experience of altering mash temps to say much on the matter. So I could only guess that it doesn't matter.

 

[aspiffymofo]

Reminds me about what they were talking about in this thread.
https://www.homebrewtalk.com/f36/two-strikes-enter-one-mash-leaves-480478/

 

[Beer is good]

Highly fermentable? More alcohol?? :rockin:

 

[masskrug]

Yes. I've mashed overnight (~6-8 hours) on a few occasions, starting at 150'-155' and dropping to as low at 130'. I did not notice any off flavors or conversion problems. In fact, I got a little better conversion.

 

[myndflyte]

Not always better though. If your style calls for a thicker mouth feel (think stout) a lower mash temp will make the beer feel thinner, if that makes sense.

 

[aspiffymofo]

Just re-read the section on how the mash works in palmers book. Pretty thorough explanation. Here's an online copy:
http://www.howtobrew.com/section3/chapter14.html

 

[aspiffymofo]

My question is if I start a mash at 150 and it dwindles down to 140 over an hour, what happens? Is the conversion still happening? How much of a problem is this?

Thank you

Alpha-amylase is active from 140-168 and Beta-amylase is active from 140-150
You should be fine, and with a highly fermentable wort! Although I don't know how you're losing 10 degrees in an hour. Sounds like you might not be hitting the initial temp you thought you were.

Edit: I don't lose more than 2 degrees in my 75min mashes. I'm using one of those square "ice cube" coolers with an old blanket thrown over the top.

 

[beersk]

Edit: I don't lose more than 2 degrees in my 75min mashes. I'm using one of those square "ice cube" coolers with an old blanket thrown over the top.

I also usually lose a couple degrees. It's concerning that the OP is losing that much in an hour. I'd guess he's doing BIAB and mashing in a kettle? Even a crappy cooler shouldn't lose that much in an hour. Look at getting something better or wrap your kettle in blankets, OP.

 

[Beer is good]

I also usually lose a couple degrees. It's concerning that the OP is losing that much in an hour. I'd guess he's doing BIAB and mashing in a kettle? Even a crappy cooler shouldn't lose that much in an hour. Look at getting something better or wrap your kettle in blankets, OP.

I used my mash tun that I just made, with a thick folded up towel on top.

Here are two photos I took after I made it

 

[Beer is good]

Alpha-amylase is active from 140-168 and Beta-amylase is active from 140-150
You should be fine, and with a highly fermentable wort! Although I don't know how you're losing 10 degrees in an hour. Sounds like you might not be hitting the initial temp you thought you were.

Edit: I don't lose more than 2 degrees in my 75min mashes. I'm using one of those square "ice cube" coolers with an old blanket thrown over the top.

Yeah something seems wrong. Maybe my little cooler has poor insulation. I am thinking about what to do now. It seems like I do always lose 8-10 degrees per hour though. Could it be partially due to my low volume of mash? I think the total grains + water is 4 quarts.

 

[beersk]

Possibly, but it shouldn't drop that much, I wouldn't think. Could just be the cooler isn't the best for mashing. Hard to tell...

 

[negativereaction]

I'd guess it's more about accurate temperature measuring, and preheating your mash tun. If you're just tossing your grain and water into a cold/room temp tun, it's going to eat a lot of your heat, but you won't see it immediately. So you'll add your grain/water, measure your temp, think you're fine, close it up for an hour, and come back to find it has dropped 10 degrees since you first measured it (because the tun itself stole the heat).

Long story short, you should pre-heat your tun with hot water first, OR (what I do), add my hot water first, let it sit in the tun until it gets to my target strike temp, then add my grain. At that point, you know the tun has stolen all the heat it will steal, and you just have to account for the heat your grain will steal.

Lotta thievery in the process of making beer.

 

[ScrewyBrewer]

Slightly off topic but mash pH in the 5.6 or higher range provides a sweeter fuller bodied beer just as a mash pH in the 5.4 or lower range provides a thinner higher alcohol beer.

I thought it is worth mentioning since many brewers never look that closely at their water profiles and think that only mash temperature is responsible for a thinner more fermentable beer or a sweeter fuller bodied beer.

 

[ScrewyBrewer]

Yeah something seems wrong. Maybe my little cooler has poor insulation. I am thinking about what to do now. It seems like I do always lose 8-10 degrees per hour though. Could it be partially due to my low volume of mash? I think the total grains + water is 4 quarts.

Pretty sure you meant four gallons here.

 

[deuce40]

Dont want to tread jack but i have a similar question. I do BIAB and do first runnings then dunk sparage. I let first runnings sit till I finish sparage (10 minutes) without doing a mash out. Would that short amount of time that the first runnings sit and temp is dropping, would there be more alpha activity make my wort more fermentable.


Sent from my iPhone using Home Brew

 

[Kee]

If you have a lot of head space in your cooler and don't preheat sufficiently you can easily lose if not ten degrees, something approaching that. (Remember that when measuring temperature that the mash tun can have hot spots if not vigorously stirred so a reading can be a couple of degrees off).

Your wort (as others have mentioned) will wind up highly fermentable, although at 140 conversion can take a little longer.

 

[Beer is good]

Pretty sure you meant four gallons here.

No I meant 4 quarts, I do 1 gallon batches...

 

[ScrewyBrewer]

No I meant 4 quarts, I do 1 gallon batches...

Nice job on the mash tun build! I was thrown off by the size since I've used a similar design on my own mash tuns before. If we can rule out too much headspace and you're preheating the tun with 180F water before adding in your strike water and grains then that type of cooler probably lacks enough insulation. Maybe try wrapping the entire tun in large towels being sure to double up on the lid, they're notorious for heat loss.

 

[william_shakes_beer]

I've also read a lot of threads that some coolers don't have a great deal of insulation in the lid. Coolers are made for cold, which sinks. Heat rises, meaning the lid is more important6 for our mpurposes than the purposes the cooler was made for. Check by drilling a small hole in the lid. If its hollow, try spraying in some expanding foam.

 

[Beer is good]

My lid is simply a single layer thin piece of plastic

I did put a towel on top. Maybe I need to wrap it in horse blankets.

 

[wobdee]

I think from what I read the enzymes take 30-60 minutes to denature as they go out of they're optimum temp ranges but theres many variables. Beta takes longer to convert than Alpha probably because starch doesn't fully gelitinize in its temp range.

I like to hit both enzyme optimum temp ranges when I mash and Change the times at each for different styles.