I'm not honestly sure myself. I generally lose no more than 2-3C during an hour with my cooler.

 

If I’m mashing at 152°, I’ll plan on starting the mash at 153. When it falls to 151, I’ll put the heat on for a bit. It’s easy to overshoot it. Nothing says you can’t turn the heat back on. Make sure you stir.

 

The big thing is conversion. You can get conversion during a pretty wide range of temps. Some of the best beers I've brewed were under my target temp for mash. Until I got new equipment, I just started a few degrees high and let the temp drop through my desired range. I jacked up my grain weight once and mashed at 145 with no issues. Some styles are more sensitive to it though. Lower is dryer. Higher is sweeter.

 

If you're working in a cooler, temperature drop is inevitable. Also, the outsides of your mash will be cooler than the middle. So, in general, don't worry about it too much unless you're using some kind of active heating system. Most conversion happens early on and the warmer temperatures denature beta amylase so my general advice, don't worry about it too much.

 

Since it's pretty impossible to micromanage the temp of the entire mass of water and malt that's doing the work of making sugars for you, the best thing you can do is be consistent in your process, temp monitoring, timing, etc and judge from the resulting wort how best to run your mash. If you mash in at a certain temp, stir a certain amount, rest for a certain time and come out with the desired fermentability and residual sweetness and body then duplicate that process as closely as possible. If you need more attenuation, start lower and if you're lacking body, etc, start a little higher.

 

Seems you are making beer,CONGRATZ!!! BIAB is a good way to get started, or hell if your me, it is a good place to end up after a decade of brewing. A few degrees over an hour never hurt anyone or the beer. Take notes, use the notes you take. If I could tell younger brewer me anything, it would be to take notes and use the notes I take.....

T

 

I hated that my mash temps weren't consistent over the hour long mash and I wanted repeat-ability so I made a surprisingly simple mini E-Herms system to do 2 things for me. 1) Recirculate the mash 2) Keep Consistent temps. I already had a pump so I have the mash go from the mashtun, to the pump which sent it to a 10' coil of copper in a small stock pot on top of a hot plate, controlled by an stc-1000 to keep temp. It was a simple and inexpensive solution for keeping mash temp and also producing clear wort.

 

So... I'd love to hear how the first two batches have gone - show pics if you got 'em!

 

In the colder months I use a converted 10 gallon round cooler and seldom see more than 2 degrees drop during a 60 minute mash. I use a heavy towel on top of the MLT and stir twice. During the hotter months I do BIAB and have been playing around with ways to maintain temperature.

Having seen the results of some experiments where tasters couldn't reliably distinguish beers that were mashed at some fairly extreme temperature differences, I'm about ready to just start with an initial temperature 4 to 6 degrees F above what I would normally mash at and leave it alone for 90 minutes when doing BIAB.

 

Don't worry about it too much. Most of the conversion happens early in the mash, before the temperature drops much. In fact, today's base malts can completely convert themselves in 20 minutes.

 

I'm with Nosy. If you start a lot higher than intended then you are converting at that temp versus what you intended to convert at. I'd try hitting the intended mash temp and let it fall.

 

As long as you are having new and different #[email protected]^& moments, you are on the right track....

 

Great brewers are built on many, many #[email protected]^& moments.

 

I've been doing it for about 16 months now with all grain and I still have those moments. Like pouring a couple liters of sparge water on the floor the other day cause I got distracted.