I’m new to the forum. I recently purchased a Blichmann controller for my MT and I was just curious what other owners have experienced?
I’ve done a lot of testing with plain water but my first and so far only brew with the new controller was on a mild winter day here in Ohio with an ambient temp of about 50F. Please keep in mind this is the first RIMS I’ve used so I’m still setting my expectations. I found that the temp in the MT was about 2-3F lower than the RTD was reading. So while the controller showed it was maintaining a temperature of ±.5F the MT was low. Later I did some checking of the digital thermometer that I used to measure the MT temp and it was within -.4F of the RTD when they were both placed in the same bath. My digital therm is reading a little low but not by much. After exchanging some emails with Blichmann about this I was told that it is due to thermal losses in my system. I have since taken measures to insulate my hoses, piping and kettle. I won’t know how much help this is until I brew again, which should be in the next week or two. Has anyone else noticed this temp difference? Have you checked it? Again this is my first experience with RIMS but having some insulation seems to be important if you are brewing outside in cold temps.
I was also curious if anyone, who uses the TopLink software, has played with the “steady state offset” parameter? If you watch John’s video he suggests not messing with it but while testing my system with only hot water (after I applied the insulation) I do see a steady state error (temp difference between the set point and actual value) of about .4-.5F lower. I know this is within specs but keep in mind that these tolerances build on themselves. .5F low at the controller and 2-3F in the MT and you are way off your desired mash temp. I adjusted the steady state offset and was able to bring the steady state error to almost zero. John says this might make the system unstable however.
Anyway, any anecdotal experiences you have to share would be interesting. Regardless of the idiosyncrasies I still believe this is the most accurate system of its kind. Most people using PIDs like Love and Auber aren’t getting anything close to ±.5F. I’m just interested in learning to optimize my system for best performance.
I don’t own the system, but I’ve used it fairly recently. Based on my recollections, I don’t see how your MT temp would be lower than the system-readout. Where do you have your temperature probe?
Also, much to my chagrin, I learned that the “flashing” numbers on the Tower mean the temperature isn’t set. The system fooled us because it still worked okay, but not perfectly, until we figured out how to “set” the target temp (this was for a step mash) and thereby eliminated the flashing numbers.
My RTD is located in exactly the same place as it is in the Tower of Power. In other words, it is in the recirculation flow of the wort coming out of the MT. Here is a picture of my plumbing.
I was surprised that there was a temp difference too but I guess if you lose enough heat from the MT it will be impossible to keep the MT at the set temp unless you are heating the wort that is being recirculated back into the MT to a higher temp. That’s why I insulated the MT.
I’ve not had any problems setting the temp on the controller.
I’ve improved some things since this drawing was made but this shows how things are connected in general.
For clarity: The Blichmann setup is a Recirculating Direct Fire Mash System - RDFMS
RIMS: Recirculating Infusion Mash System
RIMS uses a RIMS tube with an electric heating element in it to infuse heat into the system. RDFMS uses an external heat source to add heat to the system
You will always lose some heat from between the mash tun and the temp probe. The temperature probe in your system is measuring the wort just after it is being hit by the heat from the external heat source. Subsequently, you are most likely measuring the temperature of the wort at the top of the mash tun. Unless this was a 100% thermally sealed system, there will always be some heat loss. I use a RIMS tube in my setup, and I typically see +/- 2F difference in temperature, depending on where I’m measuring the temperature of the wort in the system. What I aim for is an average temperature throughout the system. You can do the same or shoot for no part being at a higher maximum or lower minimum. FWIW, a degree or two difference in the mash doesn’t really make a difference. Just shoot for something and keep it the same from then on out, or try a few things and see what works best for you.
Thanks for the clarification on differences between RIMS and direct fire. So where is your sensor? Do you measure as the wort leaves the tube? Have you taken any steps to insulate? I guess with a system like you describe you could actually mash in a cooler since you aren’t applying heat directly to the MT.