Robobrew Temperature Trend Data

[micraftbeer]

I recently spent some time with a Robobrew electric unit, trying it out. I made 2 batches of beer and found some significant temperature discrepancies between what the unit was reading and what I measured with my lollipop digital thermometer. So I did a couple of experiments heating strike water to different temperatures and I recorded the temperature with my thermometer and compared it to what the Robobrew was reading.

I found that there were some significant differences, but the unit held temperature very steady at a set point. The controller was intelligent enough to just turn on the 500W element, even though the switch was on allowing it to use either the 1000W, 500W, or both combined. So it had gradual temperature control as I kept in recirculation (with the recirc pipe valve 1/2 open).

With these kind of numbers, although I'd have to do some mental math and adjust set the controller to a higher set point than what I wanted in the rest of the mash, I could still use the system and controller as they were to provide good control. I'm not sure I'd even bother with insulation either since the level of temperature control while recirculating was pretty impressive (within 1 degree and very stable).

Have any other Robobrew users done any similar temperature measurements or messed around with insulation?

Full review is here: http://www.homebrewfinds.com/2017/10/hands-on-review-robobrew-all-grain-brewing-system.html

 

[EventHorizonBrewing]

Yikes. Where in the world is their thermocouple at?

 

[micraftbeer]

Thermocouple is in the bottom of the main vessel. So it will see the hottest wort, which is next to the heating coils. Keg King's preference of locating it there is that they can protect you against a scorched bottom, which is true. So I'm thinking that as long as I keep the wort circulating, I can just use a mapped out temperature correlation to what the temperature is up above in the main body of the mash. I then control the temperature I want where I want it, and if for some reason I get a glob of grain or hop matter that sticks to the bottom and starts burning, the temperature sensor will still detect it and turn off the heating elements as I go over the target temperature.

 

[jlinz]

I have a Robobrew. I take the discrepancy as inherent to any electric system. I suppose you could use two thermocouples, but that would be a whole new set of problems. One temp probe has to either be near the heating element or away from it...

 

[TexasWine]

I take the discrepancy as inherent to any electric system.

Don't know that I would make this assumption. I've been running my electric system in a counterflow HERMs configuration the past several brew days. After a few volume changes of the mash tun the temp probe reading, which is on the wort return to the MT, reads the same as the probe I stick in the grain bed. Even as I ramp temps, they stay within two degrees of each other.

It'd bother me to no end to have the offset displayed in these graphs.

 

[micraftbeer]

It bothered me a lot at first. On brew day when I had reached my target temperature with the controller and I stuck my thermometer in just for a quick check, I was shocked to see a big discrepancy. Being that far off threw my brew session out of whack and I scrambled to make sense of it on the fly.

On my second brew session, I tried to compensate by just taking the ~7 degree difference I saw and applying that to everything. But since I was trying to do a multi-step mash starting at 100F, the 7 degrees didn't work for me and I found myself off in the weeds again.

I haven't brewed since I did these temperature characterizations, but I feel I've got a better understanding of the characteristic and how I'd approach it. I'd use the trend data to pick an appropriate offset based on the target temperature I'm after. And seeing how steady it held a set point temperature, I'd be comfortable working with the offset I saw at saccharifaction rests and knowing it would hold steady there running on recirculation.

Of course, I'd love to not have to do the manual math adjustments, but I think it would be workable for me. Or I'd just use the offset I saw at sachharification rest temperatures and just apply that across the board. Then I'd be where I wanted at that key mash step temperature and a few degrees off at other steps which aren't as temperature critical.

 

[jlinz]

Don't know that I would make this assumption. I've been running my electric system in a counterflow HERMs configuration the past several brew days. After a few volume changes of the mash tun the temp probe reading, which is on the wort return to the MT, reads the same as the probe I stick in the grain bed. Even as I ramp temps, they stay within two degrees of each other.

It'd bother me to no end to have the offset displayed in these graphs.

I meant any of these urn type systems.