Kettle Insulation/Acceptable Temperature Drop in Mash

[Epos7]

I brewed a 10 gallon batch yesterday. I made a cap for my lid out of Reflectix, and used two sleeping bags instead of one. I also threw a couple sheets of tin foil on top of the burner in a half baked attempt to stop heat loss there.

It took five minutes of stirring after dough in to break up all the dough balls, and which point my mash temperature was 154.5F. I wrapped everything up and checked back in at the 30 minute mark, 25 minutes after I had put all my insulation on. Gave it a good quick stir to make sure the heat was distributed evenly, and my temp was 152.5F. I decided to refire the burner, brought it back up to just over 154F, and wrapped it back up again. At the end of the mash I was down to 152.5F again.

So with a 10 gallon batch and extra insulation, I was losing about 2.5F every 25-30 minutes. That's a lot better than my 5 gallon batches, but still required me to fire up the burner once during the mash.

I like the idea of pre-heating the sleeping bags, I'm just not sure how I would do it.

 

[RM-MN]

I brewed a 10 gallon batch yesterday. I made a cap for my lid out of Reflectix, and used two sleeping bags instead of one. I also threw a couple sheets of tin foil on top of the burner in a half baked attempt to stop heat loss there.

It took five minutes of stirring after dough in to break up all the dough balls, and which point my mash temperature was 154.5F. I wrapped everything up and checked back in at the 30 minute mark, 25 minutes after I had put all my insulation on. Gave it a good quick stir to make sure the heat was distributed evenly, and my temp was 152.5F. I decided to refire the burner, brought it back up to just over 154F, and wrapped it back up again. At the end of the mash I was down to 152.5F again.

So with a 10 gallon batch and extra insulation, I was losing about 2.5F every 25-30 minutes. That's a lot better than my 5 gallon batches, but still required me to fire up the burner once during the mash.

I like the idea of pre-heating the sleeping bags, I'm just not sure how I would do it.

Not if conversion was complete at 25 minutes. Did you check?

 

[Epos7]

Not if conversion was complete at 25 minutes. Did you check?

It was most of the way there. I hit 14.1 brix (1.057 SG) at the 30 minute mark, and ended up at 15.3 (1.062 SG) by the end of the mash.

 

[jwalk4]

I like the idea of pre-heating the sleeping bags, I'm just not sure how I would do it.

Probably would require you to lift/move your kettle, which some might find dangerous. But I would put down some wood or brick at the bottom of an old sleeping bag, then heat up all your water. Once youre 5-10 degrees higher than your strike temp, move the kettle onto the bricks and pull the sleeping bag up around it.

 

[JDXX1971]

I have been trying to control temps by wrapping jackets around the kettle and also firing the burner occasionally. I can keep it pretty close if I am attentive and pay attention but its sucks the fun out of it. I live near the coast and our property is heavily effected by coastal breezes. I believe that to be a big issue for some of us in particular areas. Now for me the real concern is the ability to create the same beers time after time as close as I can get them. I figure with the differences that are attainable by brewing a particular beer at different temperatures gives me some reason to be concerned with my mash temps???

But whatever, you know, I am going with a RIMS tube so I can Rdwhahb. Different strokes for different folks!!

 

[pricelessbrewing]

I've heard a lot of people say this who know a lot more than me, but it doesn't match up with my observations. I'm milling my grain pretty fine with a mill gap set to 0.020" and I typically take a gravity reading every 15 minutes during the mash, making sure I'm stirring well before taking the sample. My conversion process is always ongoing over the whole 60 minutes, often with an increase in gravity after I squeeze the bag. I do get pretty good conversion so long as I stir a lot, but it does seem to take the full 60 minutes.

I haven't tried the iodine test yet. Maybe I will try that next batch I brew to see if it confirms my gravity readings.

I will recommend checking your mash pH, and using bru'n water if you're not already. Adequate mash conditions should give maximum gravity by 50 minutes at the latest. Crush, dough in, and mash pH

 

[Epos7]

I will recommend checking your mash pH, and using bru'n water if you're not already. Adequate mash conditions should give maximum gravity by 50 minutes at the latest. Crush, dough in, and mash pH

I have been checking my mash pH and it is right where it should be. For the batch I brewed a couple days ago, I lowered my mill gap even further to 0.015" and my conversion efficiency shot up to over 97%. Conversion did appear to proceed faster as well, with it being mostly finished after 30 minutes

 

[Kee]

I grew weary of the temperature swings and got a cooler and put my BIAB in that.
Problem solved. Its another thing to buy and clean, but I don't have any spilled wort from pulling the bag out.

I bought a cooler last week and that's my plan.

 

[wilserbrewer]

I grew weary of the temperature swings and got a cooler and put my BIAB in that.

Problem solved. Its another thing to buy and clean, but I don't have any spilled wort from pulling the bag out. With a cooler I can also do re-circulation, step mashes and batch or fly sparging if I want to. So it really opened a lot of options for me.

But another way to raise the temperature of the mash is to have a side pot with boiling water ready.

Check the temp every 20 minutes, then add the correct amount of boiling water to bring the temperature up. You don't have to take the insulation off, but taking the lid off and stirring in the boiling water causes heat loss, so you are chasing a moving target.

Use the rest calculator on the Green Bay Rackers web site to determine how much boiling water to add, seems to work pretty good.

Many brewers just don't worry about it and the beer comes out fine.

Has there been an appreciable change in the beer now that you are not weary over mash temp?

I'm just not convinced it all that critical w
Modern highly modified malt.

Some feel yeast selection far influences
Attenuation more than mash temp.

 

[Kee]

Has there been an appreciable change in the beer now that you are not weary over mash temp?

I'm just not convinced it all that critical w
Modern highly modified malt.

Some feel yeast selection far influences
Attenuation more than mash temp.

I am also skeptical that a few degrees in mash temperature makes much difference. Still, I'm going to try the cooler method just because I'm used to using a cooler mash tun and believe the transition to BIAB will be more comfortable for me that way.

 

[JDXX1971]

Gee, a few degrees?? So far all my mashes ( a big six) have lost a few degrees in 10 minutes or less. But Like I said the coastal influence here is strong. Might be better in the summer but highly unpredictable because of the fog that rolls in whenever it gets too nice or it will get windy. We have pretty unstable temps here day to day, hour to hour and minute to minute sometimes. I am sure with enough insulation temp swings could be made more stable but seems like six of one half dozen of another kind of deal.

 

[beertastic]

Quilt secured with bungee cords at the bottom. Burner base wrapped 80% around with aluminum foil <- *Important*

How do you mean you wrap the burner base with foil? Around the burner? On top? I don't follow... I feel like my kettle is pretty well insulated, but losing temps through the bottom.