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Joshua618

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I recently built a RIMS with a PID to contol it . I have a couple of questions about mashout. I am using a keg with a false bottom as a MLT and a March pump. The heat exchanger is a 4500W heating element running on 110 VAC. After recirculating the mash for one hour I would like to raise the temperature of the mash to 168-170 before sparging. After the recirculating, I turned up the temperature on the PID and it took a long time to get the actual mash temperature to rise. This was on a 5 gallon batch. I have a thermometer measuring the temperature in the MLT. The sensor for the PID is located immediately after the heating element, before returning to the MLT.

Should I set the PID to 168-170 or higher?

Would reducing the flow through the heat exchanger heat the water better? Should I leave the valves wide open during this step?

Any suggestions to get the RIMS to mashout better would be greatly appreciated. Thanks.
 

missing link

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I run my system the same as you do but with a 1500 Watt element. If I do a 50 minute Mash and a 15 minute mashout, I only get to 160, and this is with my valves wide open. Slowing the flow will slow the heating.

I sparge with 180 degree water and by the end of the sparge my grain is at 168 - 170 which tells me I have rinsed with the proper water temp.

Linc
 
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Joshua618

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Those numbers look similar to what I got during my first brew session. Sparging with water around 180 degrees is what I had in mind too. I was kind of surprised how slowly the heat exchanger raised the mash temperature to mash out. Does anýone else have any other suggestions?
 

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The bottom line is that it's only enough power to really maintain temps. How well is your MLT insulated? The more the better obviously but I don't think it will give you what you want. You'll really need to run 240v for quick stepping.
 
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Joshua618

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Thanks for the replies. I will stick to using the high temperature sparge water to raise the mash temperature to mash out. I am using two layers of the shiny insulation from home depot that covers the entire sides of the keg MLT.

Should I still increase the temp on the heat exchanger and let it run for a bit after the full hour to get it up to 160ish before sparging?
 
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Joshua618

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I don't know if I should start a new thread for this or not...

What water/grist ratio should I be using with a RIMS system? I have been using a 1.25 quarts per pound of grain ratio when I was batch sparging at it worked well. Since there is water that is recirculating in the system, do I need to change the water/grist ratio?

Your help is greatly appreciated.
 

The Pol

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This is the issue with HERMS and RIMS. IT IS NOT FOR QUICK STEPPING TEMPS. You do NOT want to overheat your mash water through the HERMS or RIMS heater to ramp up quicker.

Meaning, it does not matter how large your element is... 1500W will step up just as fast as 4500W. Why? The wort leaving the heater will only be 168F if you are mashing out anyway. You should not set a higher temp than you are targeting. Do not set 180F when you have a target of 168F... because now you are just overheating the top half of your mash (return line) while the bottom of the mash is still cold. DO NOT set 160F if your target is 150F... again, you are heating half your mash to 160F while the rest is still cold.

You are limited by your temp setting, not your element. For this reason, RIMS and HERMS are not useful for quick steps. If I mash at 153F, it takes me 20 minutes of recirculating to get to 168F in my HERMS, that is just the limitation of the system.

I personally mash with 1.5-2.0 qts/lb
 

Ryan_PA

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You do have to overshoot the HEX temp slightly to compensate for temp loss between the probe and the grain.
 

The Pol

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You do have to overshoot the HEX temp slightly to compensate for temp loss between the probe and the grain.

Agreed, in my system though this ammounts to 3F....

My point again was temp ramping. You cannot ramp up faster by overshooting your target temp to do so. Youd have to overshoot it by a wide margin to get a noticeable reduction in ramp time. In doing so, you are introducing an undesireable variable into your process.

There seems to be this idea that a larger element in a RIMS heater will speed your temp steps, and it wont by a large margin, if at all. The limitation is not the element as much as it is the process by which you are heating. Raising a mash to 168F with 173F water takes a long time. There is a lot of thermal mass there to change, and if you are using a SS kettle, you are losing a TON of heat... just touch the side of the kettle, is it hot? That is waste heat.
 

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Pol, one thing I think you're not considering (I may be wrong of course) is that if you have a flow rate such that even at a set temp of 168, the wort is actually leaving at say 163F, you CAN benefit from a higher wattage in the RIMS tube if you're looking for a slightly quicker ramp. I'm not assuming this is Joshua's issue at all.

If you have a way to increase flow, that will help. If the flow is too fast for the given element to hit 172F or son on the output, you can use a higher wattage.
 

missing link

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Pol, one thing I think you're not considering (I may be wrong of course) is that if you have a flow rate such that even at a set temp of 168, the wort is actually leaving at say 163F, you CAN benefit from a higher wattage in the RIMS tube if you're looking for a slightly quicker ramp. I'm not assuming this is Joshua's issue at all.

If you have a way to increase flow, that will help. If the flow is too fast for the given element to hit 172F or son on the output, you can use a higher wattage.
This is exactly right. In a 5 gallon batch with a 1500 watt element, I can mash at 152 for 50 minutes. When I adjust my set temp to 168, my HEX does not instantly reach 168. The element turns on and stays on while the temp exiting the HEX slowly increases as the mash tun temp increases.

So if I am at 152 and adjust my set point to 168 and have my pumps flowing as fast as possible, after 10 minutes I'll see 160 at the exit of my mash tun and 164 at the exit of the HEX. I'll generally see a 4 degree difference top to bottom as I try to heat the mash. Once the HEX reaches the set point I see less than 1 degree variation from top to bottom.

I have thought about adjusting my plumbing with some valves so that during mashout I could flip some valves and use the HEX for HLT and HEX for MLT in series with both set to 168 degrees to halve my time to get to 168.

Linc
 

The Pol

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Pol, one thing I think you're not considering (I may be wrong of course) is that if you have a flow rate such that even at a set temp of 168, the wort is actually leaving at say 163F, you CAN benefit from a higher wattage in the RIMS tube if you're looking for a slightly quicker ramp. I'm not assuming this is Joshua's issue at all.

If you have a way to increase flow, that will help. If the flow is too fast for the given element to hit 172F or son on the output, you can use a higher wattage.
I am considering this... but like I said, I dont think you'd see much, if any, decrease in time to heat. This is more for a RIMS than HERMS... in a HERMS you are heating a large qty of water, so a larger element will help to a larger degree since you are first heating 5-10 gallons of water.

In a RIMS you are heating a small volume in an enclosed tube. Yes, flow matters and if you overwhelm the element, youare right, you wont get 168F out of the RIMS heater. My point is that the largest limiting factor is that you are heating small volumes of water at a time to raise the temp of 7-12 gallons of thermal mass in a poorly insulated vessel. A SS kettle with little or no insulation and no lid, will hemorrage heat. These systems have never been designed to ramp quickly, they are much too limited.

I dont care how large your element is, you will not get a HERMS or a RIMS to ramp up as quickly as an AG brewer would like. Mashout takes a while, step mashing without infusion would be almost impossible, if not impossible.
 

missing link

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If your recircing at a rate of say 3 gallons per minute and you are able to get the exit of the HEX to reach 168 and hold that when the mash is at 152, I would think it would take very little time to bring all of the liquid in the mash tun up to 168 if there is only 5 or 6 gallons in the tun. Every 2 minutes you are theoretically turning over the entire volume.

Though I am not able to do that with my system so I can't say if that theory is true.

Linc
 

The Pol

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If your recircing at a rate of say 3 gallons per minute and you are able to get the exit of the HEX to reach 168 and hold that when the mash is at 152, I would think it would take very little time to bring all of the liquid in the mash tun up to 168 if there is only 5 or 6 gallons in the tun. Every 2 minutes you are theoretically turning over the entire volume.

Though I am not able to do that with my system so I can't say if that theory is true.

Linc
Recirculating at 3 gallons/minute is SUPER fast. Yes, in theory it would heat the mash much faster, but I dont think a RIMS and definately not a HERMS will heat to 168F at 3gal/min.

Also, dont forget, you are only heating the WATER... then that water goes into the MLT and the grain saps the heat out of it. The grain has a lot of thermal mass and you are heating it passively...

So in theory if you can find some way (which I cannot fathom) to heat 3 gallons/min to 168F it would heat fairly fast. Though, the larger your grain bill, the more grain thermal mass you have to change as well, which takes time since you are passively heating it.

Again you are limited since I have never seen anyone operate a RIMS with 4500W for fear of scorching the wort... that being said, you wont get 168F through a RIMS tube with 3gal/min with a low wattage element.

In theory, many things are "possible", but the limitations of the process itself are hard to overcome.
 

missing link

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Recirculating at 3 gallons/minute is SUPER fast. Yes, in theory it would heat the mash much faster, but I dont think a RIMS and definately not a HERMS will heat to 168F at 3gal/min.

Also, dont forget, you are only heating the WATER... then that water goes into the MLT and the grain saps the heat out of it. The grain has a lot of thermal mass and you are heating it passively...

So in theory if you can find some way (which I cannot fathom) to heat 3 gallons/min to 168F it would heat fairly fast. Though, the larger your grain bill, the more grain thermal mass you have to change as well, which takes time since you are passively heating it.
I didn't think about the thermal mass of the grain. I receirc as fast as the pump will go, so whatever that flow rate is.

I think even the pro-brewers plan for 15-30 minutes for mash-out don't they?

Linc
 

The Pol

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I didn't think about the thermal mass of the grain. I receirc as fast as the pump will go, so whatever that flow rate is.

I think even the pro-brewers plan for 15-30 minutes for mash-out don't they?

Linc
I dunno... but I get there in about 20 min, that is what I use. It is good for a mashout, but not for step mashing. For step mashing I have a fairly complex spreadsheet that calculates my volumes, HEX temps and heating times to manage the entire process for infusion mashing.
 

N5629

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Could some of this be rectified by placing the PID sensor at the outflow of the MLT rather than the HEX out?
 

The Pol

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What about a direct fired RIMS? I know I should be going for max flow (as much as possible without over compacting the bed), but how much heat should I be applying to the bottom of the MLT?
That is a good question... how can you quantify the ammount of heat you are applying? If you cannot measure it, you will really never know how much you ARE applying, so the question of how much SHOULD you apply is a moot point.
 

The Pol

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Could some of this be rectified by placing the PID sensor at the outflow of the MLT rather than the HEX out?

Bad idea.... this has been debated to death, with a few HBT members having some horrible brew sessions and finally moving the temp sensor to the RIMS or HERMS outlet.

If the PID only "sees" the MLT outlet, it has no idea how hot it is getting te HERMS or RIMS outlet wort... that could be 180F, and that is bad. But, the PID wont see it if you are measuring the coldest point in the process.
 

FSR402

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What about a direct fired RIMS? I know I should be going for max flow (as much as possible without over compacting the bed), but how much heat should I be applying to the bottom of the MLT?
This is what I'm planning to do. My plan is to use my flash boiler at a low flame and a high flow to mashout. I know that at full flame and and 2 gal/min I can get a 40* increase so by running the flow at max my pump and manifold/grainbed will alow I'll contol the flame to get the temp I need.

I will give it the first try on my next brew when I will have 60+ pounds of grain in the tun.
 

JVD_X

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Well - what is an acceptable ramp-up time? Is ramping over 20 minutes affect the mash significantly differently than ramping over 10?
 

The Pol

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Well - what is an acceptable ramp-up time? Is ramping over 20 minutes affect the mash significantly differently than ramping over 10?
I would think that ramping over 20 minutes from protien to sacc. rest would be a little excessive due to the ammount of time (conversion) that takes place during that time.
 

N5629

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What about using a double RIMS chamber - a split feed, two elements and the thermocouple at the joined outflow. You'd get the heating of two elements, but you'd also have to deal with the power requirements of the two. Could this decrease ramp time and make step-mashing feasible?

This is off-topic and I apologize, but...Pol, where did you get the geared motor for your HLT stirrer?
 

The Pol

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What about using a double RIMS chamber - a split feed, two elements and the thermocouple at the joined outflow. You'd get the heating of two elements, but you'd also have to deal with the power requirements of the two. Could this decrease ramp time and make step-mashing feasible?

This is off-topic and I apologize, but...Pol, where did you get the geared motor for your HLT stirrer?
I have never heard of a dual heating chamber, but if you can double the heat and the volume, it would be faster. How fast? Someone would have to build it to try it.

My stirrer came from McMaster Carr. If you sift through my HERMS build thread, you will see the motor, coupler and stirrer part #'s there.
 

JVD_X

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I am using the same RIMS system as Linc and it takes me about 20 minutes to get to mashout temp. I am thinking - in general - that we lose a lot of efficiency between when the fluid leaves the mashtun to the time it re-enters the mashtun.

If the original poster could insulate and physically shorten that process, more heat could be conserved.

Also - I SPECULATE - that a series or parallel system of lower wattage HEX/PIDS independently controlled could reach target temps much quicker than just a single unit high watt HEX.
 

N5629

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Well that is that then. This summer, when I am not occupied with trying to be a good and financially sound college student, I will build one of these dual chamber suckers and see what good it does. If somebody else gets it in mind to do this before me, I won't be annoyed, after all, the laboratory mouse is always glad when the guinea pig offers to take that random injection in his place. Or something.
 

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Another idea would be to place the heating chambers in series. I think the end result would be the same, more energy over a larger thermal area, but only one PID would be nessessary.
 

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I use the same rims system but have a propane burner under my mlt also. I reach temp changes in a few minutes.
 

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I was able to step from 122 to 158 over 20 minutes with a direct fired RIMS (10 gallon recipe). Jamil's Belgian Wit directions say to do it in 15 minutes. If you can do 20 minutes through a RIMS, that would be fine with me.

The point I was trying to make is that the faster you can flow through the RIMS tube, the more wattage you can make use of. Hypothetically if you flow 2gpm and your wattage only gets you a 5F temp rise between the in/out of the RIMS, doubling the wattage conceivably gets you a 10F rise instead. It wouldn't help you reach mashout in half the time, but it has to be worth the effort. No matter what, I'd want the output of my RIMS to be at my set temp at whatever my max flow rate was.

This would be the ideal situation but small departures from it wouldn't be that big of a deal either.
 

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We could increase the pipe size from the usual 1/2" to [a larger size] to increase the flow rate. I am also interested if a low-density element of identical wattage as a high density element heats at different rates because of exposed area.
 

The Pol

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Compare the BTU output of a burner on a direct fired unit, to the BTU of a heating element in a RIMS heater.

5500W = approx. 19,000 BTU... how many BTUs is your burner?

So if you had THREE 5500W elements running at 5500W each, you would have just under 60k BTU.

Typical RIMS heating element:

1500W = approx. 5,200 BTU
 
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Joshua618

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It is relieving to hear that I am not the only one with slow ramp-up times to mash out on a RIMS.

What water/grist ratios are you guys using on a RIMS system?
 

JVD_X

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I have been using 1.25 but recently moved up to 2.0 because of a recent thread. I actually saw a decrease in my efficiency with a thinner mash, which leads me to believe that - at least in my personal RIMS system - a thinner mash doesn't work as well as a thicker mash. I'm still confused as to why it is an issue moving from 150 to 170 over 20 minutes rather than 10. If the conversion is done, the conversion is done right?
 

The Pol

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I have been using 1.25 but recently moved up to 2.0 because of a recent thread. I actually saw a decrease in my efficiency with a thinner mash, which leads me to believe that - at least in my personal RIMS system - a thinner mash doesn't work as well as a thicker mash. I'm still confused as to why it is an issue moving from 150 to 170 over 20 minutes rather than 10. If the conversion is done, the conversion is done right?
I dont think anyone said that there was a problem with ramping up to mashout over 20 mins... it just takes a long time, lengthening the brew day. It shouldnt affect the beer in any way, I dont think that was the point of the thread.

Now in a previous post we were talking about ramping up from say 122-158... that could be a problem, because conversion is not complete and you will be converting sugars for a long period during the ramp, instead of at your target temp.
 

JVD_X

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I recently built a RIMS with a PID to contol it . I have a couple of questions about mashout. I am using a keg with a false bottom as a MLT and a March pump. The heat exchanger is a 4500W heating element running on 110 VAC. After recirculating the mash for one hour I would like to raise the temperature of the mash to 168-170 before sparging. After the recirculating, I turned up the temperature on the PID and it took a long time to get the actual mash temperature to rise. This was on a 5 gallon batch. I have a thermometer measuring the temperature in the MLT. The sensor for the PID is located immediately after the heating element, before returning to the MLT.

Should I set the PID to 168-170 or higher?

Would reducing the flow through the heat exchanger heat the water better? Should I leave the valves wide open during this step?

Any suggestions to get the RIMS to mashout better would be greatly appreciated. Thanks.
It just occurred to me... did you run the autocalibration routine on the PID? This might explain you long ramp times.
 

Bobby_M

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You could argue that step mashing doesn't really require instantaneous adjustments anyway. This is an organic thing where activation of the enzymes that favor the next temp range and the denaturing of the previous has an overlap anyway. You could plan your ramp up to start a little sooner and you can achieve repeatability. This is especially true due to lower temp enzymes being slower.
 

The Pol

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I would have to assume though that if it takes 20 minutes to ramp to mashout temps... so 153-168F, that it would take nearly 40 minutes to ramp from a protein rest to sacc. rest. That to me seems like it would be very long. It would no longer be a step mash, but simply a ramp mash.

Again, if you have a direct fired RIMS you have more capability than the guy heating with 5,000 BTU in a little RIMS heater. You have what, 60k or 100k BTU at your disposal? Of course it takes him 20 minutes to mash out, the math supports it, it has nothing to do with his PID or any other variable. You have a finite ammount of heat introduced and a HUGE thermal mass to change.

How many BTU is a stove top? 9,000? How many of you can reach a boil on a stove top with 5 gallons? Now take his 5,000 BTU in his RIMS heater and try increasing the temp of a 7 gallon mash.

Direct fire, or infusion is about the only way to have a short step time. Though, back to the OP, 20 minutes is normal with 5,000 BTU at your disposal and should not affect the beer.
 
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