mash rest

[jtoots]

do you stir during the mash rest?  i haven't been, and i've noticed the following in a couple recent batches:

i'm using a cylindrical cooler for my mash tun.

-i hit my mash temp before closing the lid dead on.
-at the end of the mash i lift the lid and take temp readings in the middle and around the edges.
-around the edges the temp has gone down slightly, as expected (a degree or so).
-in the middle the temp has actually gone UP a couple degrees, as if the heat has migrated into the center of the tun.

any thoughts?  should i adjust my starting temp to account for this?  should i stir once during the rest?  all good, proceed as i have been?

thanks all!

[HoosierBrew]

I stir thoroughly, until I get a pretty uniform temp throughout the cooler, then close the lid and leave it alone - the lid doesn't open until it's time to sparge.

EDIT - During the course of the mash, there would likely be some temp stratification throughout the cooler/tun, and temps usually drop a degree F or two, but no worries. A lot of good beer has been made in this fashion by a lot of brewers.

[erockrph]

I tried stirring a few times. When I stirred I ended up losing about 5 degrees over the course of the mash. No stirring gives me about a 2 degree loss. Needless to say, I stopped stirring.

[jtoots]

Thanks for the replies, gents.  Do you notice the same trend, heat gain in the center of the tun?

I'm thinking that, for example, if I'm aiming for a rest temp of 153, and the center of the tun is at 155-156 by the end of the hour, maybe I should start at 152 to account for this gain.  That said, the edges of the tun drop down to about 151, so the average temp is probably right where I want it and I shouldn't change anything.

[HoosierBrew]

..... so the average temp is probably right where I want it and I shouldn't change anything.

That's always been my thought. Don't over think it. Good luck !

[davidgzach]

Thanks for the replies, gents.  Do you notice the same trend, heat gain in the center of the tun?

I'm thinking that, for example, if I'm aiming for a rest temp of 153, and the center of the tun is at 155-156 by the end of the hour, maybe I should start at 152 to account for this gain.  That said, the edges of the tun drop down to about 151, so the average temp is probably right where I want it and I shouldn't change anything.

I've never had heat gain in the middle of the tun.  Are you sure you are mixing thoroughly to start?

[jtoots]

Are you sure you are mixing thoroughly to start?

Yep, I'm sure, and didn't believe it the first batch I saw this.  Strange, right?  I'll be brewing this weekend, looking for it again. 

[denny]

Thanks for the replies, gents.  Do you notice the same trend, heat gain in the center of the tun?

I'm thinking that, for example, if I'm aiming for a rest temp of 153, and the center of the tun is at 155-156 by the end of the hour, maybe I should start at 152 to account for this gain.  That said, the edges of the tun drop down to about 151, so the average temp is probably right where I want it and I shouldn't change anything.

How long do you stir when you mash in?

[jtoots]

How long do you stir when you mash in?

I add water first, then add grains a couple pounds at a time, stirring after each addition.  Once all the grain is in and no clumps exist, I use my digital thermometer to get readings in a few locations while stirring to get temp down a couple/few degrees to my target temp.  The flaw I recognize here is that the thermometer isn't reaching down to the bottom of the tun... however, with all this stirring, I don't think stratification would be a major factor (and presumably the top would be the hotter region, and the vertical distance isn't all that significant especially for a 5 gallon batch).  I'd say all in all this takes 5 minutes plus although I've never actually timed myself.  I'll use a timer this weekend.

[denny]

How long do you stir when you mash in?

I add water first, then add grains a couple pounds at a time, stirring after each addition.  Once all the grain is in and no clumps exist, I use my digital thermometer to get readings in a few locations while stirring to get temp down a couple/few degrees to my target temp.  The flaw I recognize here is that the thermometer isn't reaching down to the bottom of the tun... however, with all this stirring, I don't think stratification would be a major factor (and presumably the top would be the hotter region, and the vertical distance isn't all that significant especially for a 5 gallon batch).  I'd say all in all this takes 5 minutes plus although I've never actually timed myself.  I'll use a timer this weekend.

Well, it sounds OK, but without being able to read the temp all the way to the bottom I guess you can't know for sure.  Based on what's happened to me before, I'd guess that you don't have heat distributed well enough to begin with.  But that's just a guess.

[Plmac]

Are you preheating your mash tun? How hot?  I don't worry about the end temp as much as getting my starting temp stabilized.  Conversion is usually done within 30 minutes and yes I let it sit for 60 minutes just in case.

[denny]

Are you preheating your mash tun? How hot?  I don't worry about the end temp as much as getting my starting temp stabilized.  Conversion is usually done within 30 minutes and yes I let it sit for 60 minutes just in case.

I spent several years preheating the tun, then had a revelation...if I just tracked how far off I was without preheating for a few batches, I could come up with how much hotter I needed to make the water.  Works great and I haven't preheated in years.

[hopfenundmalz]

Are you preheating your mash tun? How hot?  I don't worry about the end temp as much as getting my starting temp stabilized.  Conversion is usually done within 30 minutes and yes I let it sit for 60 minutes just in case.

I spent several years preheating the tun, then had a revelation...if I just tracked how far off I was without preheating for a few batches, I could come up with how much hotter I needed to make the water.  Works great and I haven't preheated in years.

Many do it that way. Easy, it is.

[Plmac]

Are you preheating your mash tun? How hot?  I don't worry about the end temp as much as getting my starting temp stabilized.  Conversion is usually done within 30 minutes and yes I let it sit for 60 minutes just in case.

I spent several years preheating the tun, then had a revelation...if I just tracked how far off I was without preheating for a few batches, I could come up with how much hotter I needed to make the water.  Works great and I haven't preheated in years.

Many do it that way. Easy, it is.

Totally agree, I was just thinking if his mash tun was holding heat like a heat sink it could raise the temp.  I guess the real question, Is your beer coming out the way you expect it to?  To sweet?  Mouth feel? Final Gravity as low as you expected?  Mash temp to High?

[klickitat jim]

Are you preheating your mash tun? How hot?  I don't worry about the end temp as much as getting my starting temp stabilized.  Conversion is usually done within 30 minutes and yes I let it sit for 60 minutes just in case.

I spent several years preheating the tun, then had a revelation...if I just tracked how far off I was without preheating for a few batches, I could come up with how much hotter I needed to make the water.  Works great and I haven't preheated in years.

If it took me several years to preheat my tun, I would try to find a better way too.