Question about RIMS

[waverz]

I have a small DIY RIMS system I mostly use just for clear wort and to help maintain mash temps. I have always struggled with low mash conversation efficiency and am wondering if the way I'm operating my system is the cause.

I have the thermal couple about 6" inches downstream from my small 600watt cartridges heater. One thing I noticed is while the temperature seems well maintained coming out of the tube, the temperature of the mash tun itself is usually around 5-8 degrees lower that what the actual "mash temp" should be.

I guess my question is, Should I bump up the temp on my controller so the actual mash tun is maintaining the temperature that the recipe calls for or do i set the contoller to that temp?

 

[Bellybuster]

Insulate your mash tun and hoses. That will go a long way.
8 degrees lower? That'll explain conversion issues

 

[augiedoggy]

Something is not right it sounds like one of your temp probes is not accurate. You may need to adjust your pid to correct the reading. Unless your brewing out in really cold temps 6-8 degrees is highly unlikely.. I recirculate at about 1.9 gallons per minute and see about 1-2 degree max variance. I use an uninsulated stainless MT.

 

[kh54s10]

If your mash temperature is low you will need to adjust the temperature of the Rims system to keep the mash temperature correct. I agree that something is off. You will need to check things out to find out which temperature is correct and adjust things accordingly. If that means that you just have to run the Rims 6-8 degrees higher, so be it. But it would irk me that the temperature readout was not correct.

 

[waverz]

I mash in an insulated cooler without the lid. I am wondering if my thermocouple is located too close to the heat source giving me inaccurate readings.

I could be losing a lot of heat in the non insulated lines going from the heat back to the mash tun .

I will experiment with thermocouple placement to see if it yields a better match conversion efficiency.

 

[thekraken]

How long are your lines? If you can mash with the lid it will help. What size batches are you doing? How fast are you recirculating?

 

[waverz]

The lines coming out of the tube are approximately 3 to 4 feet and are silicon.

I think measuring the temperature coming out of the hose rather than inside the tube might help.

I am doing 5 gallon batches.

 

[thekraken]

The lines coming out of the tube are approximately 3 to 4 feet and are silicon.

I think measuring the temperature coming out of the hose rather than inside the tube might help.

I am doing 5 gallon batches.

3-4 feet total, before and after the tube? I really don't think you could be losing that much heat from the lines. How fast are you recirculating?

 

[waverz]

There's a foot if line between the pump and tun and about 4 foot after. I'm doing some tests with just water at the moment and I think the solution my very well be in flow rate. I feel I may be circulating much too quickly.

 

[augiedoggy]

I mash in an insulated cooler without the lid. I am wondering if my thermocouple is located too close to the heat source giving me inaccurate readings.

I could be losing a lot of heat in the non insulated lines going from the heat back to the mash tun .

I will experiment with thermocouple placement to see if it yields a better match conversion efficiency.

if my rims probe was any closer to my element it would be touching... and thats a good thing here.

I also have about 7ft of silicone line and a flowmeter inline which doubles as a sightglass.

BTW I started with a 10" 800w cartridge heater and now use a 36" long cartridge heater.... the length insures long contact time and lower watt density so no denaturing of enzymes and poor efficiency...size matters pics are in my build thread below.

 

[thekraken]

There's a foot if line between the pump and tun and about 4 foot after. I'm doing some tests with just water at the moment and I think the solution my very well be in flow rate. I feel I may be circulating much too quickly.

Interesting. I was thinking you might be pumping too slowly. Are the temp probes you're using calibrated?

 

[waverz]

Figured it out. Decided to brew a batch and do some experimenting. I basically just have a silicon hose coming from my tube going into the mash tun . Being all the heated wort is basically running into one spot of the tun that area maintained temperature while areas in the mash away from the hose output cooled considerably. I built a manifold drip system out of some CPVC and I noe have a nice consistent heated mash.