Unexpected increase in efficiency

[nobby]

For the first time I have used my new 24 Litre Thermo box BAIN MARIE. What a joy to use compared to a cool box. Much easier to dough in and clean.

There thermo efficiency is incredible. Pre heated it then added my water at 74c, doughed in, hit my strike temp of 67c. After 90 minutes I checked the temp again. The middle was still 67c it was not until you got 10mm away from the wall that the temp had dropped and only by 2c.

However the biggest surprise was an increase in efficiency from 67% to 80%. Also I batch sparge!!! I put this down to several things

Less loss due to dead space at the bottom.

Better Thermo efficiency

Better sparging due to less surface area and deeper grain bed.

I think the sparging was the biggest difference. With less surface area than a cool box the sparge water pass over more grain. I drew off quite a few 2 litre jugs and returned to the top. I am still using the original tap and was drawing it off quite slowly. But it was coming out so clear.

The only down side was I was using a larger grain bill expecting 67%. I ended up with 23 litre of 1056 so had to water it down a bit to 26 litre. Still ended up a bit stronger than I wanted.