Eureka moment for temp control?

[FlyDoctor]

Greetings. I apologize if this is common knowledge and I'm just an idiot.

I BIAB with a keggle set up. The biggest problem I always had was temp control during the mash. Summer or winter - it didn't matter - temp would drop at least 2-4 degrees in the first 30 mins and I'd have to refire. To me this severely impacts the ability to actually get what you want - controlling fermentability and body with targeted mash temps. I tried wrapping with several layers of reflectix - it helped a bit, but not enough to preclude refiring the mash.

I realized my problem - I was using the stupid built in thermometer on the side of the keg. Sure, it's measuring temperature - but not of the mash. I noticed if I instead measured the temp of the mash, the temp was lower. Then the beautiful thing - when I then fired the heat to bring the mash temp up - the water/wort around the bag was actually higher by quite a bit. This is good because - as the mash temp begins to decline - the drop is buffered by the heat in the wort outside the bag. Measuring the temp of the mash - it only dropped 1F over 60 mins. This seems to only be the case if the temp measured in the wort around the bag is higher than that inside the mash (in other words - mash in low and apply heat).

I guess the question is - is the high temp in the wort outside the bag negatively affecting the mash? In other words, some of that wort is exchanging with the mash - and vice versa - the portion of the wort that is outside of the bag will have different enzymatic activity than that inside the mash.

Anyway, the beers have been better with respect to body - and slightly less fermentable (I was consistently getting bone dry ferments with low body).

I'd love to hear some feedback on this.

Cheers

 

[wilserbrewer]

This is exactly why I have always preferred a hand held digital stick as opposed to a kettle mounted thermometer.

Ok, well maybe it's also because I'm lazy and cheap. The digital sticks just work so darn well and they are dirt cheap and accurate.
Cheers!

 

[RM-MN]

This is exactly why I have always preferred a hand held digital stick as opposed to a kettle mounted thermometer.

Ok, well maybe it's also because I'm lazy and cheap. The digital sticks just work so darn well and they are dirt cheap and accurate.
Cheers!

Most are cheap and accurate. I got one that is right on at room temp, off 3 degrees at mash temp and off by 7 at boil. I was disappointed but for the cost I could afford to just discard that one and replace it.

 

[jnacey]

It's interesting that my grain temp during the mash actually tends to be higher than the liquid. I usually do a pretty aggressive stir before I measure temp for this reason. Hrmm..

I've been BIAB mashing in a 10gal cooler and that has helped with my temp control.

As far as for thermometers, while the cheap ones are accurate, I found that they're also prone to breaking easily. After going through a few of them, I sprung for a Thermapen during one of their open box sales. I'd say its one of the better purchases I've made.

 

[Brewcycle69]

I have the same setup and the same issue with the keggle thermometer. I found a 4 - 6 degree difference between the liquid outside the bag vs the grain temp inside the bag. Each time I stirred the mash the temp would change a few degrees. I removed my keggle thermometer and use an electronic thermometer with a wire prob I drop into the mash to monitor the temp. I also recirculate throughout the mash, I found recirculation really keeps the mash temp completely consistent.

 

[Woodbrews]

I also recirculate throughout the mash, I found recirculation really keeps the mash temp completely consistent.

What type of pump do you use and how fast to do you run it? Have you noticed any problem with the pump losing prime because the wort does not flow through the bag quickly enough? Finally, do you recirculate through a fitting in your lid, through some other type of arrangement? Thanks!