Mash tun too big?

[Mojzis]

I had built myself a 10 g mash tun out of a new circular cooler, ss braid, bronze ball valve etc.

I built it with the idea of 5 g batches, but lately i've been doing mostly 2.75 g batches. Since i've only been brewing for 9 months, I like the small batches as "test" batches. When I figure out what is good, what I like, and how not to screw up I make a 5 g batch.

Here's the problem. When I do a 5 g batch I lose maybe 1 degree an hour. If that. Lately, i'm losing 8+ in a 2.75 g batch. It's starting to get to me .

I'm pretty sure that there is just too much dead space in the tun. My thermometer lays just on top of the water inside and I have to tilt it a little to get a real reading. Also I think the lid sucks a**. Its the only part besides the ball valve that I can feel heat coming off.

So what do you guys think? I won't be buying a smaller mash tun, maybe if I can find a scrap one i'll go for it. Can I insulate the lid in anyway? It seems like the lid is hollow and just uses air as an insulator. Should I drill a hole in it, buy a can of great stuff, fill it and seal that hole?

 

[kluge9]

You can make a false lid for your smaller batches. Get a sheet of exterior insulation and cut it to fit inside your MLT. Wrap it in tin foil to make sure you don't lose any of the little scraps and to help reflect heat back into your mash. It can sit right on top of your mash

 

[Mojzis]

Ahhh I don't know why I didn't think of that. I'll try that, thanks!

 

[cluckk]

You could just make a smaller one with two stacking buckets. Punch dozens of holes in the upper one and a drain hole fitted with a barbed fitting in the lower. When you fill it wrap it in several towels to insulate. You could also mash in a small cooler and transfer by hand to the homemade later tun. I also know people who use brew in a bag for small test batches.

 

[November]

You can make a false lid for your smaller batches. Get a sheet of exterior insulation and cut it to fit inside your MLT. Wrap it in tin foil to make sure you don't lose any of the little scraps and to help reflect heat back into your mash. It can sit right on top of your mash

I do this with my 70qt MLT when I make low gravity 5g batches and it works great.

 

[wilserbrewer]

I have heard that simply laying folded up aluminum foil on the grain bed will help keep heat in...an easy fix perhaps?

 

[kingwood-kid]

1. Preheat the heck out of the mash tun.
2. Mash thick, then add more hot water after 30 minutes and stir.