chiller
Well-Known Member
- Joined
- 27/4/04
- Messages
- 619
- Reaction score
- 18
At 4.00 am one morning I woke with a start. A direct heated mash tun, why not.
I needed a vessel to convert -- existing 50 litre aluminium HLT.
A manifold to fit -- the one from my 38 litre rubbermaid was exactly right.
A source of heat -- now for a very brief moment I considered another jet burner [nasa ] but the idea of scrapping a scorched mesh out of the tun didn't appeal.
I visited all things hot -- globe imports and they had this minute single ring burner that looked as if it would do.
Insulation for the tun [not while flame is on]. A cheap camping mattress from clarke rubber and I was ready.
I estimated the small burner would raise the tun 1 degree per minute and it did so the temperature increase wasn't too rapid.
Despite the fact most grains now are fully modified I have always tried to do a rest at 50, 60, 70 and 75C but with hot water additiuons you run out of tun very quickly.
My first step was spoton 50C which I held for 10 minutes and then applied heat to raise the temperature to 60C. This took 10 mionutes and during each temperature increase I gently moved the mash to prevent any scorching. The next rest at 60 C was held for 30 Minutes and even though the tun is Aluminium and only had a rubber camp matteress for insulation the temperature didn't change at all in the 30 minutes.
The next step was 70C and again this took 10 minutes to reach temperature. and was held for 30 minutes as well.
I usually don't worry about a mash out but with direct heat it was a breeze. 75C for 10 minutes and then start the sparge.
The runoff was very clean and my efficiency is up by about 4% using my normal batch sparge.
My biggest concern was burning the mash but with a small gas flame and the Aluminium pot for heat distribution I didn't have any problems.
I use Sodium Met in my mash so the extra movement of the mash won't cause any problems.
As an aside the extra efficiency is probably due to the stirring of the mash as the temperature is raised.
Steve
I needed a vessel to convert -- existing 50 litre aluminium HLT.
A manifold to fit -- the one from my 38 litre rubbermaid was exactly right.
A source of heat -- now for a very brief moment I considered another jet burner [nasa ] but the idea of scrapping a scorched mesh out of the tun didn't appeal.
I visited all things hot -- globe imports and they had this minute single ring burner that looked as if it would do.
Insulation for the tun [not while flame is on]. A cheap camping mattress from clarke rubber and I was ready.
I estimated the small burner would raise the tun 1 degree per minute and it did so the temperature increase wasn't too rapid.
Despite the fact most grains now are fully modified I have always tried to do a rest at 50, 60, 70 and 75C but with hot water additiuons you run out of tun very quickly.
My first step was spoton 50C which I held for 10 minutes and then applied heat to raise the temperature to 60C. This took 10 mionutes and during each temperature increase I gently moved the mash to prevent any scorching. The next rest at 60 C was held for 30 Minutes and even though the tun is Aluminium and only had a rubber camp matteress for insulation the temperature didn't change at all in the 30 minutes.
The next step was 70C and again this took 10 minutes to reach temperature. and was held for 30 minutes as well.
I usually don't worry about a mash out but with direct heat it was a breeze. 75C for 10 minutes and then start the sparge.
The runoff was very clean and my efficiency is up by about 4% using my normal batch sparge.
My biggest concern was burning the mash but with a small gas flame and the Aluminium pot for heat distribution I didn't have any problems.
I use Sodium Met in my mash so the extra movement of the mash won't cause any problems.
As an aside the extra efficiency is probably due to the stirring of the mash as the temperature is raised.
Steve