A case for herms

[oldjiver]

I have been quite pleased with the heat retaining properties of my IGLOO mash tun, but I got a surprise while doing a mash yesterday. I usually fill the tun to the top with liquor a few degrees over strike heat and let it settle a few minutes to pre -heat. Then when at correct temp I drain it to the correct amount of liquor for the mash. I doughed in at 66c and checked after one hour, it had dropped .4c to 65.6 So I was happy. HOWEVER I then gave it a stir for no real reason and checked again. It now measured 64.5c. I hadn't realised how much difference there would be between top and bottom. Not enough to make a real problem but a good case for re-circulation.

 

[kev]

Ehhh no.

A good case for increasing your strike temp and stirring more.

K

 

[oldjiver]

Ehhh no.

A good case for increasing your strike temp and stirring more.

K

Problem is if you increase your strike temp you get a different Maltose/ Dextrose profile, and if you keep taking the lid off and stirring you lose temp.

 

[Vossy1]

I would have thought that it doesn't matter if you hit strike temps and stir properly, unless you have a 100% insulated system with no losses you'll lose heat, and by losing heat you'll create thermoclines in the medium, it can't be avoided..unless you use a heat replacing system (HERMS/RIMS)
(not that that's a reason for one of those systems, beer's been made for 1000's of years without them, it's just me thinking aloud...lol)

 

[oldjiver]

My point Vossy was that I originally thought HERMS was a lot of fuss for very little return. That was when I thought my super insulated IGLOO tun was losing .4c in an hour. Now I know that the mash has different rates of loss between top and bottom I can see the point of recirculating systems.

 

[Vossy1]

Yep, get your point oj, my comments were more to avoid it looking like I laud all things HERMS/RIMS....lol. Even the shiny thermopots show the same variance in temps through the mash, and those variances are one of the reason I use a HERMS...bit of a control issue for me...lol

 

[oldjiver]

Control freak eh?

 

[kev]

Problem is if you increase your strike temp you get a different Maltose/ Dextrose profile, and if you keep taking the lid off and stirring you lose temp.

Ah I see what you mean. You're talking about post-mash. I thought you were saying that your mash temp was far too low BEFORE you'd started the rest.

I take temp readings all over the grain and stir like a mad man until they're equal. Even after the mash I check temp in multiple locations and they're within 0.1c of each other.

What tun are you using?

K

 

[oldjiver]

I use an IGLOO tun. I pre-heat, calculated the strike heat and stir a lot until it settles at the desired 66c. I usually check after an hour and the drop measured on my digital thermometer 4 inch probe is usually between .2c and .5c. But I havent been checking deeper as I didn't want to get my wrist wet! This time I stirred the mash up again and found the average drop for the hour was 1.5c. Still within reason but not as good as I thought it was.
Heres mtylovely tun..

 

[kev]

That's weird. I'll stir up my mash after an hour this weekend and give it a go.

See what happens

K