Help with mash temps

[Polarbeer]

Hello all,

Well I'm currently mid brew and had a couple questions:
1. I mashed for 90 min and lost about 6 degrees. From what I've read this is not normal. About 45 min in I put plastic bags on the top thinking this would help my head space loss, but it really didn't work the way I would have liked. What is the best thing I can do to maintain mash temps?
2. I often have problems hitting my mash temps exactly where I want them, and its frustrating. I guess my question is when correcting for temps (ie if I dough in lower than I want) is it better to get the temp up to 154 and sacrifice my water/grain ratio or is it better just to be at lower temps?
3. When is the best time to measure for efficiency? After boil I'm assuming..?

Despite my low temps I'm drinking my belgium white as I brew this IPA and I like it alot! Here's to a great Sunday afternoon

Thanks

 

[zachattack]

I can answer your 3rd question...

I would measure the pre-boil gravity after you finish sparging. That way you can calculate your mash efficiency, and while the wort's coming to a boil you can think about how to fix it if it's not at the gravity you intended (boil longer before adding hops, weigh out some DME, add some top-off water, etc.)

After the boil you can measure again, but if you know your boiloff rate and therefore post-boil volume you should be able to calculate it pretty well from the preboil SG.

 

[Northcalais40]

I'm not sure I understand you completely with the plastic bag bit, but a sleeping bag/ blanket or a jacket always improves temp drop in the mash.

 

[Polarbeer]

I'm not sure I understand you completely with the plastic bag bit, but a sleeping bag/ blanket or a jacket always improves temp drop in the mash.

I just read that you can put plastic grocery bag on the top of your mash to decrease head space. I have been wrapping my mash tun with 2 blankets but still can't seem to keep temp with it. I'm wondering if its my mash tun or what exactly it is.

 

[Yukmay]

Some variables to keep an eye on when temps are off:

Preheat the mash tun with boiling water prior to doughing in.
Include the grain temp in your calculations! Most programs use 68 degrees so if the grain comes out of the garage/basement at 50 degrees the mash temps will be off.
Wrapping the cooler in blankets helped me as well.

Cheers!

 

[timdsmith72]

I've only done a couple of AG batches, but here's how I've managed to hit my temps. For example, if my calculations say that I should dough in with 165 degree water, I add my mash water to the tun when it's in the ~180 degree range. I then let it cool down to my desired temp and then add the grains. That pre-heats the tun for me.
Another thing I do is shoot for about 2-3 degrees OVER what I really want. After I dough in, I take a temperature reading and if it's too warm, I stir the s*it out if it until it drops to the temp I want. (usually a couple of minutes.)
I put a blanket or two on top of my mash tun during the mash. That holds the temps nicely.

 

[Pappers_]

Are you using Beersmith?

 

[TyTanium]

Another thing I do is shoot for about 2-3 degrees OVER what I really want. After I dough in, I take a temperature reading and if it's too warm, I stir the s*it out if it until it drops to the temp I want. (usually a couple of minutes.)

+1 So much easier to reduce temp than to increase it. If you're way over, ice cubes one-at-a-time give you a very consistent, repeatable temp reduction method.

As for maintaining mash temps, I've found that airflow makes a huge difference. When mashing outside I was losing 2-4 degrees, even on warm nights with only a mild breeze. By simply moving inside to a room with no airflow, I only lose 1-2 degrees, if that.

Most of the conversion happens pretty quick, first 30mins or so, so I wouldn't be too concerned with a little drop. If it really concerns you, add a quart of boiling water halfway through to give it a boost.

 

[MedicMang]

to answer the deadspace question... I have been using a 70 qt cooler mash tun and have had some trouble maintaining the temps as well. i experimented with the last two batches with just getting enough tinfoil to fold in half and cover the whole top of the "wort in progress", then cover with blankets. This worked great. I had less than 2 degrees loss over the whole hour. Good Luck.

 

[Polarbeer]

Thanks guys. Ya I was mashing for 90 min so that was a long time to start with. But even when I mash for 60 min I still have a 4ish degree loss. I guess this isn't a huge deal because common these are enzymes... they are around because they are able to function and serve a purpose. If they only functioned at one temp then they would have been negatively selected by now. I know that temps also have to do with tannins.... but just saying.

Love the aluminum foil idea. I was even thinking of cutting a piece of foam board to put on top of my mash and covering it with aluminum foil.

I'm definitely stealing the mash in hot and add ice cubes well. Great stuff!

 

[jfrizzell]

Curious to see what answers you get as well. Designing my brew stand system and wondering about temp probe placement myself.

It seems that in a direct fired RIMS, if you are cycling the burner based on the outlet temperature, the burner would cycle constantly. Maybe it doesn't heat the wort up that fast but it seems like you wouldn't get a good representation of the mash temp.