Sully: What temp do you keep the water in the HE at and do you pump the wort through until you reach the desired temp in the MT. My thoughts were to hold the water temp in the HE at just under boiling IE: 95C and keep circulating to raise temps in MT until I hit the desired temp not withstanding overshoot of course which would need to be ironed out during setting up.
Cheers
Regarding HE water temp. My HE temp adjusts to whatever the temp needs to be to have the wort exiting the coil at my exact desired temperature. I actually measure and control my temp from just above my sparge arm as it enters back into the mash tun which isn't very far from the HE coil exit anyway). Frankly I dont care, nor need to know what the HE water temp is as long as my wort coming out of that coil is exactly where I want it to be, which is my set point. If that means my HE is boiling well that's fine because my wort temp is still only at 65C or whatever the temp is set at. The reality is that my HE temp is usually at my set point temp, maybe a degree above. if I want to raise temp I change the set point value on the controller and a minute or two later the temp exiting the HE is at the new temp (assuming the jump isn't too high). I have a very small volume of water in my HE (4L) and use a 1200W element with stirring and it works fine and responds
very quickly because it's such a small volume (300W/L). Sounds small but that 300W/L is actually better than a 2400W element in 10L (240W/L), well the results seem to follow that logic anyway :unsure: . But I do also only use my HE to maintain temp and mash out, I dont bother to step mash and if I did I'd probably employ the additional help of my hand held element to make things fast and easy. Having said that it will raise the temp just fine as I use it to mash out.
What I do in initial set up is get my HE going, mash water volume corrent and pumping around until I have everything sitting at my desired strike temp. Then I turn the pump off and HE element, set my PV (set controller to my desired temp) and
then start doughing in. By the time I've doughed in, mixed it thoroughly, allowed a minute to settle, then I start opening the valve slowly to start drawing liquid through and set the bed for the mash my HE has usually dropped a degree or two and with the first running it pulls the HE water temp down to the desired temp. That sounds way more complicated than it is but it has worked great and because there is only 4L of water in there it doesn't take much for it to auto correct to the necessary temp.
RE setting the HE temp at 95C, not a real good idea IMHO. If you are holding your HE water at 95C that means if your heat exchanger is any good then the wort exiting the coil is going to be 95 also (if it can pick up temp that fast which it should get pretty close I'd say, but that is a big temp differential). In the meantime you will be creaming those enzymes going through the heat exchanger, and probably quite quickly too (the higher the temp the faster denaturing occurs). This is not really the idea of a herms if you ask me. It may work(?) but I wouldn't do it that way.
I'll also second Jimmyjacks comments, insulate your HE cause you might as well. In fact for the best results I'd insulate your hoses too if you can. Silly to pull hot liquid out, allow it to cool, heat it up again, let it cool and put it back from where it came at the same temp at what it would have been if you just left it there. Insulation on your HE will have nothing to do with temp overshoot unless you need to shed temp from you HE because you are already over temp, which indicates a problem in how you've set up your control system and running your system. I suspect that overshoot problem mentioned above was because the HE water temp was hotter than it needed to be before the wort was pumped through and hence it needed to loose heat to get back to the required temp. The lack of insulation would speed that up. That's why I pump everything round for a while until the system is in equilibrium and stable before I let grain hit the system. Given how quick conversion is done, if you are spending 15-20 mins fiddling trying to hit your temp then you blew it IMO and a heap of the conversion is already done. Dont belive me, do an iodine test at 15mins and see what it reveals. This depends on grain bill of course but if you dont have large amounts of adjuncts or highly kilned malts it will churn through that starch in no time.
Good luck with it. Ok, tired of rambling on and spewing my thoughts. Hope it might give some help.
Justin
I guess it makes my opinions invalid lol
