Question Maintaining Mash Temp in a Direct Fired RIMS?

[Rudeboy]

After two plus years using a converted cooler and the stove top for AG I just got two 10 Boilermakers and Camp Chef burners to go outside.

I use one of the Boilermakers with a false bottom as my MLT. First brew last weekend I initially hit my strike temp spot on (with BeerSmith’s help) but found I was losing close to a degree a minute I added some heat and turned on the pump for the RIMS part but I overshot the mash temp a bit even on lowest setting so I turned off the heat and pump. On-off, on-off for the whole 90 minute mash. So my question is two fold.

First is there a better way to avoid yo-yoing around the exact mash temp with a direct fired RIMS?

Second is there an easier way to do this. I guess I was spoiled but with my Coleman Xtreme I never lost more than a degree an hour. I’d strike in and come back an hour later to vouralouf. Am I just going to have to always babysit the direct fired RIMS system for the whole mash? What do people do when they have no pump, ie. Gravity fed pot-style MLT (like a More Beer 500 system)?

Thanks Rudeboy.

 

[Catt22]

1. IMO, it is nearly impossible to manually operate a direct fired RIMS. My experience doing so was nearly exactly the same as what you described with constant babysitting required and a lot of lighting and extinguishing the burner, yet still overshooting and undershooting the target temps. My solution was to automate the burner with addition of a gas solenoid valve operated with a Johinson A419 digital controller. This made all the difference. I mounted the valve directly on my low pressure Camp Chef burner and I have the controller probe monitoring the wort temperature on the output side of the pump. I also have a digital thermocouple thermometer with the probe positioned half way deep in the grainbed and half way from the center to the side of the MT. I use the thermometer to govern and adjust the controller as needed using a 1 degree offset. This has been working very well for me. I circulate the wort as fast as I possibly can and continuously for the entire duration of the mash.

2. Yes, there is an easier way to do it and that's using a cooler or some kind of insulated MT as you previously did. You won't have as much flexibility as with the RIMS, but it is much easier if that's what you are after. I started out with a direct fired MT and no pump. I manually circulated by draining the wort into a 2 liter SS measuring cup and pouring it back into the top of the MT while frequently turning the burner on and off. This was a lot of work and the main reason I bought a pump. The pump opened up a whole new world of problems and operating the RIMS manually with the pump was somewhat better, but still a lot of work and it required constant babysitting.

I've got my direct fired RIMS running smoothly now, but it took me a very long time to get to this point. Automating the burner was the biggest improvement. I highly recommend doing so with yours.

 

[JuanMoore]

Insulating the MLT and lid with relectix or other insulation also helps a lot. It may not look as pretty, but it will help keep temps even and hold temp much better.

 

[Lonnie Mac]

I would agree with Catt (to some degree)... Automating the temp control will be a great upgrade. But I must challenge the premise that you are loosing one degree per minute, or even close to that. That is impossible my friend, even in Alberta! If you heated your mash to 152 or so, even left unattended in Siberia at sub zero, you would not loose one degree per minute... This tells me that you are having trouble with your temp measurements, your temp gauge itself, or the process by witch you are taking your measurements. It would be good to get a handle on that. With thermal mass in account, and my thin (very thin) pots and my 99 degree heat in the garage, My mash pretty much will hold my strike temp for an hour by itself. I rarely recirculate unless I have to... I think I have misstated my process on my website... If I DONT have to expend the energy, and there is no reason to recirculate, I don't feel the need...

As for taking the temp in the center of the mash, (substitute the word mass here), It is the last place in your mash (mass) that feels the heat you are trying to apply. So the rest of the mash above has already exceeded your desired set temp, the mash below has not reached it, and your burner is off, thinking it has done it's job. I have really sucked at trying to explain why it is important to take the recirculation temp reading at the source of the heat, that way your mash (while having to play catch-up) can NEVER exceed your set point.

 

[ScubaSteve]

It IS possible to lose right around 1 degree a minute. Sorry Lonnie, that Texas weather has spoiled you! A vessel at 160F can easily get to 100F in 60 mins in the dead of winter. I live in Chicago and have been in several situations where the maintaining the mash in an uninsulated keg is utterly hopeless. Hell, engine blocks can crack in this weather! Blankets make a huge difference; reflectix is prettier.

Honestly, for RIMS, I think an electric version might give you the control you're after. Insulation of your lines and vessel are key.

 

[Lonnie Mac]

You dang cold weather people!

 

[ScubaSteve]

Yeah, it's a slippery slope. The chill water is wicked cold, but so is the ambient temp. It's a huge reason why I'm building an electric rig....not to mention that the wife will nag less if I'm not in the garage for 6 hours

In the winter months, "no-chill" is pretty easy. I get a hell of a cold break just leaving the kettle on my garage floor

 

[Bobby_M]

That's why I'm hesitant to recommend a direct fired uninsulated RIMS system and it is true that location matters. I regularly brew in 40F ambient in my uninsulated garage.

The direct fire capability is great for heating strike and making step mash/mash out movements, but it's a little sketchy for heat maintenance. Even if you direct fire it for those reasons, the automated "temp hold" is much easier using a RIMS tube on a controller. Another alternative I've been toying with is electric heat tape between the tun and insulation.

 

[Catt22]

As for taking the temp in the center of the mash, (substitute the word mass here), It is the last place in your mash (mass) that feels the heat you are trying to apply. So the rest of the mash above has already exceeded your desired set temp, the mash below has not reached it, and your burner is off, thinking it has done it's job. I have really sucked at trying to explain why it is important to take the recirculation temp reading at the source of the heat, that way your mash (while having to play catch-up) can NEVER exceed your set point.

I generally don't agree on this. I also did not suggest taking the temperature in the center of the grain bed. I said half way down and half way between the center and the outside wall. Yes, the actual center will be hotter than near the outside wall and the top portion will also be warmer than the bottom when circulating. I believe that the best we can shoot for is the average grain bed temperature. I also believe that continuous circulation will help to maintain a more uniform grain bed temperature. I set the controller according to what the thermometer in the grain bed shows. There's a big difference between ramping up temperatures vs simply maintaining the grain bed temp. I manually adjust both the flow rate and the burner flame level differently for each operation.

Yes, obviously the ambient temps have a lot to do with the MT heat loss and so does the batch size. The temperature drops will also not be anywhere close to uniform throughout the grain bed if not circulating the wort. In that case, it's anybody's guess what the true average grain temperature might be.

 

[Lonnie Mac]

Actually I would have to differ with that one... I brew every two weeks year round; that's guaranteed... It gets well below freezing here in the winter believe it or not. Funny. there is little in-between here. Either I am freezing my butt off, or dyeing in 100 degree heat. It is a matter of mechanics and simple as that... It don't matter a tube or direct fired. The mash has no idea where it is getting the heat from. What matters is how you use it...

 

[bobbytuck]

I realize this will cause some consternation for my suggesting it, but remember -- there's also HERMS. I don't know your setup -- and I don't know how much configuration you've already done -- but the indirect heat from HERMS seems (to me, at least -- and I know this is controversial) far preferable (and far easier to maintain a constant mash temp) than any RIMS solution -- especially in the colder months.

I know, this is discussion about RIMS -- but I'm just sayin' ...

After brewing on several RIMS systems locally, I'm surprised more people aren't turned on to HERMS. I think folks think it's overly complex, but it's pretty simple to me -- and with my setup, I set my HLT to 2 degrees above my MLT, recirc for the whole mash, and get rock solid temperatures that *do not* deviate over the course of the mash. If i want 154 in the mash, I will get 154 in the mash.

My plan for next month is to install a Ranco probe at my HEX-out (right now it's in my HLT -- which is why I know that there's a 2 degree differential between the HLT temp and my target mash temp). All I care about is the HEX-out temperature. I don't care about the HLT, and I don't care about the internal temp of the mash (at the top, middle, bottom, etc.). Once I do that, I won't even have to worry about the temp differential. I just tell it to monitor the HEX-out and adjust my heating coil accordingly. The mash will never go above my HEX-out, and because I recirc the HLT with my second march pump, the differential will always be 1 or 2 degrees -- enough for my 5500W HLT element to make nearly instant (one or two minute) temp adjustments. This should also provide rock solid temp control no matter the weather.

 

[Rudeboy]

Thanks everyone.

Last weekend was around 20 C ambiant (68 F) so it wasn't that bad. I might have exagerated the heat loss a little, but only a little. Definately over 5 degrees F in 10 minutes.

It might be the temperature probe a bit. It was my first brew on the Blichmman 10 Gallon Boilermakers. It was JZ's Cream ale so a pretty small amount of grist and the boilermaker probe was submerged but only barely. So it might have been more abt to temp swings than dead centre of the mash.

I'm not sure if I'm up for the auto RIMS but a manual HERMS might be in the works.

On the temps here I'll only be able to brew outside until November because of, ironically, cooling issues. You have to make sure to drain and purge all outside taps and hoses or they'll burst in the winter. I suppose I could pull out hoses every brew session to run the IC and then drain and purge them after every go round but that seems like a lot of water work at 40 below.

I'm going to keep working the problem but right now the thought of just striking into my cooler and going to watch "The NFL Today" for an hour seems pretty attractive.

Rudeboy