Mash temp consistency

[papagoat]

Hey guys. Yesterday I got my 3rd all-grain batch under my belt. I've seen steady improvement in efficiency. 55-64-77!!!

Feeling pretty good about it but I have a question on the best way to take a temp in the MT.
Currently I'm mashing, adding a gallon or so in a high temp mash out, and then a single batch sparge. I stir the sparge water thoroughly before vorlauf. I stick my thermometer into various locations of the grist and get different temperatures all over the place. Some variations are 4-6 degrees off. What temperature am I suppose to trust on this?

If my sparge was this wild, then I'm assuming my mash temps are the same.

Thanks in advance.

 

[BBL_Brewer]

You have to stir the mash really well to equalize the temp. If you're getting differnt readings in different places, stir some more and then check again. Once you get about the same reading in a few places, you're ready to rest.

 

[revco]

Definitely sounding like you need to stir like crazy to get even temps. Typically, on my equipment, I get about a one degree variation and usually it's a fraction of a degree. I stir for probably a good minute plus on both my initial strike and my sparge, sometimes more if I need to drop my temps. (I'm batch sparging, which it sounds like you are too.)

You might also think about using only two infusions, rather than three. There's little or no advantage to two "sparge out" steps, unless you're brewing big beers and trying to eek out every bit of efficiency, with which there's a point of diminishing return for your efforts. Just to give you an idea, I just did an 18lb 5 gallon batch with a mash/single sparge and hit 83%, where my typical is 85-88%. I attribute my efficiency to my own milling and the fact that I have less than 6oz dead space in my MLT.

 

[papagoat]

It sounds like I'm not stirring enough. I have stirred just enough to "fluff" up the grains to make sure there are no dough balls but I was scared of overstirring and heat loss.

The last 2 recipes I did both called for a mash out that's why I did so. Both were bigger beers. They became even bigger when I added 2 pounds of grain to make up for my historically low efficiency and then BAMMO my efficiency is fine.

How much can you stir the sparge water before unacceptable heat loss. I know it's a much higher temp. but I'm still nervous of heat loss after my first all-grain batch had temp problems.

 

[Denny]

Get the mash temp right. Stir until it's consistent no matter where you measure. Don't sweat the sparge temp so much. It's not that big a deal as long as you're close. Skip the mashout step and sparge with 185-190F water,

 

[revco]

How much can you stir the sparge water before unacceptable heat loss. I know it's a much higher temp. but I'm still nervous of heat loss after my first all-grain batch had temp problems.

On my first strike, I heat water to about 10 degrees over the suggested temp and let it sit in the cooler about 10 minutes to allow my mash tun to absorb heat. I'll stir the water until I get to about a degree or two over the suggested calculated temp, add my grain, and this gives me time to stir very well. (I've found it's far easier to drop temps by stirring than it is to raise them, at least with a cooler setup, so I'd rather be slightly high and bring it down with a minute of stirring.) I stir until I reach an average of about a half a degree over my mash temp, since I know I'll lose about a degree in 60-75 minutes.

With sparging, I heat to 185, dump the remaining water in and stir like crazy. I usually hit between 168 and 170 and will stir to hit 168. I drain almost immediately after adding the sparge water. Hope that helps!

 

[diS]

Get the mash temp right. Stir until it's consistent no matter where you measure. Don't sweat the sparge temp so much. It's not that big a deal as long as you're close. Skip the mashout step and sparge with 185-190F water,

Isn't this on high side of sparge temperature?
I am batch sparging and I usually sparge with 175 water, so I get somewhere around 165-170 in MLT..

Are you suggesting higher temp. because of better rinsing of remaining sugars.. or there is something else I am missing here?

 

[RM-MN]

Isn't this on high side of sparge temperature?
I am batch sparging and I usually sparge with 175 water, so I get somewhere around 165-170 in MLT..

Are you suggesting higher temp. because of better rinsing of remaining sugars.. or there is something else I am missing here?

It would be high on the sparge temperature if it raised the temperature of the entire grain bed to that amount but it is likely that the grain was cooler so that adding the water at that temp would leave the sparge in the 160-170 range, perfect for sparging. Even if it was higher there would not likely be any problem because if the mash pH was in the normal range of 5.2 to 5.4 it is unlikely that a single sparge would raise the pH over the 6.0 which is the edge of where tannin extraction could occur.

 

[diS]

That was my though too.
I am not concerned about tannin extraction since I am adjusting my sparge water, just wondered if there is something else I missed in batch sparging..

Thanks.

 

[Denny]

Isn't this on high side of sparge temperature?
I am batch sparging and I usually sparge with 175 water, so I get somewhere around 165-170 in MLT..

Are you suggesting higher temp. because of better rinsing of remaining sugars.. or there is something else I am missing here?

Not on the high side at all. I find it gets my grain bed to just under 170 and is hot enough to make sure conversion is complete. Contrary to popular belief, hotter water does not significantly reduce the viscosity or make sugars flow more easily. The reason people often see greater efficiency by raising the temp is the full conversion. And if you're worried about tannins at that temp, keep in mind that mash pH is the key factor, not temp. If it was solely temp, no one would be able to do decoction mashes, where you boil the grain. The reason that works is becasue the pH is low. Keep your pH in line and you don't have to worry about temp very much.