MoreBeer's SMART Digital System Temperature Fluctuations...Help!

[BVilleggiante]

Hello,

I have the one tier 10 gallon SMART Digital System. I've started continuously circulating the mash through the heat exchanger during my mashing process due to the fact that if I wait for my temp. switch to kick in, I get pretty large fluctuations in my mash temps. since what the temp gauge is reading in one part of the kettle may not be true for the entire kettle as it sits. So, to try to avoid these temperature disparities, I've starting sparging the entire time.

So, since I continuously circulate the wort through the heat exchanger, I am still noticing I can't seem to be able to keep my mash temps where I want them. If I set my hot liqueur tank to 122 degrees for instance, my mash tun seems to hover around 120. If I set my hot liqueur tank to 154 degrees, my mash tun hovers around 151. Has anyone else with this system had this problem, and if so, how did you over come it?

 

[bruin_ale]

sorry, by "sparging" - do you really mean sparging or do you mean circulating the mash through the heat exchanger in the HLT?

Also, a loss from HLT temp to what you get in the MLT can be a few things - but one common one is that you need to stir/mix the HLT to keep the temp uniform across the heat exchanger.

 

[BVilleggiante]

Yes, sorry...not sparging but recirculating. I'll make the change in the original post.

If my MLT temp is low, wouldn't stirring decrease the temperature even more?

sorry, by "sparging" - do you really mean sparging or do you mean circulating the mash through the heat exchanger in the HLT?

Also, a loss from HLT temp to what you get in the MLT can be a few things - but one common one is that you need to stir/mix the HLT to keep the temp uniform across the heat exchanger.

 

[bruin_ale]

Recirculating the mash the entire time is pretty common. I think most of us with HERMs systems try to recirculate for as long as possible. The benefit is as you've found, the temps are more uniform because you've circulated all the wort to get it to the same temp. Also, the wort clarity is amazing - but you don't really need to circulate for an hour to get that - maybe 5-10 minutes at most.

As you run wort through the heat exchanger, the layer of water around the exchanger loses it's heat to the wort running through the exchanger. If you aren't mixing the HLT, there will be a temp differential between the overall temp of the HLT and the temp you get out of the heat exchanger. Mixing the HLT will limit this effect because it will replace the water around the heat exchanger with water that is at the HLT setpoint. Some people mix, some people just account for the loss by turning the HLT up a degree or two.

 

[bruin_ale]

I have a temp probe on the input of my mash tun telling me the temp of the incoming wort from the heat exchanger. It usually matches my HLT temp exactly. I suggest you check that temp and see if it's different than your HLT temp, if it's a couple degrees lower then it's probably as I've suggested above. If they are the same temp, then it's probably something else.

 

[BVilleggiante]

This is very good information. So...are you mixing continuously or only at certain intervals?

Also, when/if not mixing do you keep your lid on the mash tun, or keep it off?

I know, kind of stupid questions but I'm really trying to get my temps to be precise.

How precise are you able to keep your temps. with the technique you use?

Recirculating the mash the entire time is pretty common. I think most of us with HERMs systems try to recirculate for as long as possible. The benefit is as you've found, the temps are more uniform because you've circulated all the wort to get it to the same temp. Also, the wort clarity is amazing - but you don't really need to circulate for an hour to get that - maybe 5-10 minutes at most.

As you run wort through the heat exchanger, the layer of water around the exchanger loses it's heat to the wort running through the exchanger. If you aren't mixing the HLT, there will be a temp differential between the overall temp of the HLT and the temp you get out of the heat exchanger. Mixing the HLT will limit this effect because it will replace the water around the heat exchanger with water that is at the HLT setpoint. Some people mix, some people just account for the loss by turning the HLT up a degree or two.

 

[bruin_ale]

I'm referring to mixing the HLT, not the mash. I only stir my mash when I mash-in and when I put water in for my batch sparge (even then, sometimes I skip the stirring for that).

For the HLT mixing, I stir continiously with a stir motor.
Mash tun lid is on and I keep a lid on the HLT that only has an opening for the shaft of the stir motor.

As for precision, I'm about +/- 1 degree from where I'm aiming to be - usually when I measure it's less than 0.5 degree F from the setpoint.

BTW, I don't have the MoreBeer system but my electric system is similar in that it has a heat exchanger in the HLT that I recirculate my mash through. That's not a concept that MoreBeer thought up, I don't know why they made up their own acronym for it.

 

[BVilleggiante]

Thanks for this information. I'm going to check my HLT temp. vs. the temp. coming out of my sparge ring and see if there is a temp. variation or not the next time I brew. That should help me in getting on track. I appreciate your information.

I'm referring to mixing the HLT, not the mash. I only stir my mash when I mash-in and when I put water in for my batch sparge (even then, sometimes I skip the stirring for that).

For the HLT mixing, I stir continiously with a stir motor.
Mash tun lid is on and I keep a lid on the HLT that only has an opening for the shaft of the stir motor.

As for precision, I'm about +/- 1 degree from where I'm aiming to be - usually when I measure it's less than 0.5 degree F from the setpoint.

BTW, I don't have the MoreBeer system but my electric system is similar in that it has a heat exchanger in the HLT that I recirculate my mash through. That's not a concept that MoreBeer thought up, I don't know why they made up their own acronym for it.