Herms temp drop

[IPAPatty]

I'm having big issues with my Herms system .. after i mash in my temp drops witch is expected but as i start running wort through the herms the temp drops about 15 deg and sometimes 20deg and i cant get it to rise no matter what .. also im getting stuck sparges and run off to the boil kettle. I checked my grain crush and its fine my question is .. am i not letting rest long enough ? is the pump sucking so hard that its compacting the grain bed or posibly is my false bottom to small ... i didnt think i needed to insulate my 55g mash drum for this system or insulate my hoses but would that help ?
Cheers

 

[helterscelter]

I'm having big issues with my Herms system .. after i mash in my temp drops witch is expected but as i start running wort through the herms the temp drops about 15 deg and sometimes 20deg and i cant get it to rise no matter what .. also im getting stuck sparges and run off to the boil kettle. I checked my grain crush and its fine my question is .. am i not letting rest long enough ? is the pump sucking so hard that its compacting the grain bed or posibly is my false bottom to small ... i didnt think i needed to insulate my 55g mash drum for this system or insulate my hoses but would that help ?
Cheers

lots of things going on here. :rockin:

I'm no expert, so take with a grain of salt.

it is definitely a possibility that you could have many contributing factors going on.

since you're getting stuck sparges your mash temp controll problem could be due to a lack of flow through the HERMS coil. if you cannot circulate enough wort through the HERMS to overcome the heat losses from your uninsulated mash/hoses/etc then your temps could definitely drop and have a very hard time coming back up.

it is completely possible for your pump to be compacting your grain bed due to too much flow and/or an improperly sized false bottom. on a 55G drum, I would expect the false bottom to be a raised/flat affair that basically cover the entire bottom of the drum; you may be able to use a domed false bottom as well I suppose.

while you're circulating through your HERMS, what does the flow actually look like? are you running full-bore on the pump and does it look like the sort of flow you would expect from your pump? does the flow start great and then slow down?

what does your system look like? you mentioned a 55G drum mash tun, but what does the HERMS side look like? What size is your coil? what size is the water bath? do you have any trouble maintaining the HERMS water temp? (and what do you typically set it to?)

insulation definitely helps, at least around the mash tun. you shouldn't need insulation on your hoses, but it definitely doesn't hurt.

 

[IslandLizard]

What he said. ^

That's a huge vessel!

How big a batch do you mash in that drum? Huge headspace is another reason of temp drops. Definitely check your flow rate. How hot is your HERMS vessel? Long enough coil?

 

[IPAPatty]

Today I did some testing and insulated the hoses with pipe foam wrap and calibrated the PID's and stats to within 1 degree ..hard to do when the control temp fluctuates but very close ... I did notice a closer temp difference once I ran the herms system ... I'm going to brew a batch tomorrow give the mash an uninterrupted rest and run pumps half open to see if I can raise temps .. also going to try rice hulls .. here is a couple pics of the equipment.

 

[day_trippr]

That rapid a temperature drop suggests the hlt bath wasn't up to mash temperature.
Also, with a hlt that big you might want to try recirculation or a stirrer to keep the bath temperature even.
Finally, conditioning the grain before milling will go a long way to improving flow rates and avoiding stuck mashes...

Cheers!

 

[Dcpcooks]

How big is your coil? I use a 50' in a 30 gallon kettle and it's enough to ramp at 1 degree a min. I do recirculate the HLT liquor around the coil. If that pump is off I see about a six to eight degree drop in wort temp coming out of the coil. I use that to my advantage. I can have extra heat in the HLT that I can use when I need it.

You may want to try setting your dough in temp and letting everything stabilize at that temp with all pumps running. Then turnoff the pumps and dough in. Let it sit for 20 min and then begin to recirculate your wort.

I'd also suggest you relook at your pickup tube. You probably want a false bottom. Your going to be pulling wort from a very small localized area with that set up. I use the blichmann false bottom and it's the bomb.

 

[Dcpcooks]

Now that I've looked at it a few times it's definitely your lack of a false bottom.

 

[IPAPatty]

That's what I thought and I have a new false bottom coming made for this system..

 

[Dcpcooks]

That's what I thought and I have a new false bottom coming made for this system..

That'll fix it for you!