Blichmann Boilermaker Question

So I've recently upgraded my brewing equipment to a blichmann top tier system. 3x 15gal pots, 3x burners, 2x pumps, all camlock fittings. I'm definitely spoiled. I'm two batches in...

I've never used a direct fire mash tun; I'm used to a cooler. I'm experiencing a pretty significant heat loss during my mash. Since I'm able to recirculate via pump, I draw off my mash tun, into the pump, out to my recirc port and use a little heat to maintain or raise the temp.

Here's the question: for folks that are doing this, are you ever stirring your mash to help even out the temp or are you just letting the liquid movement take care of this? I've been stirring a little and I'm feeling like I'm disturbing my grain bed and possibly plugging my blichmann false bottom in the process. My latest thought was to resist the temptation to stir and just monitor the blichmann thermo on my pot. Thoughts?

As an aside, with those of you using pumps, where are you controlling your recirc volume so you don't compress your grain bed, the pot ball valve or the pump output valve?

I appreciate the help.

Always the pump output valve - you don't want to restrict the flow going into the pump.

You can get insulating "blankets" for stainless mash tuns - they look like a layer of bubble wrap sandwiched between foil.

it helps to let the grain soak in the tun for about 10 min, whenever i skip this step i end up having to stir up the compacted grain bed within 3-4 minutes. it says to do this in the documentation that comes with the tower of power mash modules, i ignored it the first few times thinking it wouldn't make a difference but it does matter in my set up. i condition my malt before milling and that really helps make a nice husk filter. once i fire up the pump i control the flow on the outlet side and don't stir the mash at all, never have a problem hitting my numbers. using the mash module is mostly set and forget since i automatically monitors the temps and fires up the burner as needed. my temps stay within a degree of the set point.

I am using 1/2" silicone tubing with camlock fittings on my system. For the pieces in question, I use 90 degree elbow fittings for my connections. When I am recirculating, I put the elbow into the tun and open the valve completely on both intake and output. The elbow and tubing rests against the side of the kettle at the top of the mash and creates a whilrpool effect which does a pretty good job of keeping the temperature in equilibrium throughout the mash. During a rapid change, there are some places where the mash temp may differ by a degree or two, but for the most part I am quite happy with the way it works. If I had any complaint is't that I would prefer to automate that part of the process, which I have effectively done this past weekend.

Thanks for the tips. I have made it a habit to condition my grains but I haven't heard of letting the grains sit for a while before recirculating. It makes sense though; let the grains settle on their own, then run the pump.

So, I'm sensing its common practice to not stir the grains in a recirculating system and to control the flow of wort NOT at the pot, but at the pump.

Correct?

Correct. If you are using a March or similar pump, you'll want to control the flow by putting a valve on the pump outlet.

mn_brew said:

Here's the question: for folks that are doing this, are you ever stirring your mash to help even out the temp or are you just letting the liquid movement take care of this? I've been stirring a little and I'm feeling like I'm disturbing my grain bed and possibly plugging my blichmann false bottom in the process. My latest thought was to resist the temptation to stir and just monitor the blichmann thermo on my pot. Thoughts?

Click to expand...

bingo. a friend does this (recirc during mash when he fires the burner) and he ends up getting crystal clear wort and great efficiency because the constant recirculating of water sets a very fine grain bed. Since the water is always in motion, there's no need to stir.

The key to ^that^ is to have a manifold or false bottom that does not cause channeling, otherwise efficiency goes right down the tubes...

Cheers!

All good info. Thanks for the tips and advice. I'm planning on making a few changes for the next brew:

1. I'm going to grab some reflectix and wrap the kettle during the mash. IIRC it is not flameproof so any direct heat will melt or damage it.

2. I'm going to mash in, let the temp equalize and let the grain naturally settle. After 10+ min, I'll start the recirc. The plan is a wide open port on the kettle to the chugger, then control of the flow via the ball valve on the output of the chugger. I'll apply heat as necessary.

3. No stirring during the mash. I'm going to trust my thermo and let the recirc take care of business.

I'll try to report back any results.

mn_brew said:

All good info. Thanks for the tips and advice. I'm planning on making a few changes for the next brew:

1. I'm going to grab some reflectix and wrap the kettle during the mash. IIRC it is not flameproof so any direct heat will melt or damage it.

Click to expand...

i had it on my tun but ended up removing it. the keggle holds heat remarkably well, grain ended up getting under the reflectix and getting yucky. with direct heat i didn't think it was worth the trouble. it does shrink and melt with continual heat. what i started to do was heat the water in the hlt then add it to the tun so that the burner would only be coming on occasionally to maintain temps.

mn_brew said:

So I've recently upgraded my brewing equipment to a blichmann top tier system. 3x 15gal pots, 3x burners, 2x pumps, all camlock fittings. I'm definitely spoiled. I'm two batches in...

I've never used a direct fire mash tun; I'm used to a cooler. I'm experiencing a pretty significant heat loss during my mash. Since I'm able to recirculate via pump, I draw off my mash tun, into the pump, out to my recirc port and use a little heat to maintain or raise the temp.

Here's the question: for folks that are doing this, are you ever stirring your mash to help even out the temp or are you just letting the liquid movement take care of this? I've been stirring a little and I'm feeling like I'm disturbing my grain bed and possibly plugging my blichmann false bottom in the process. My latest thought was to resist the temptation to stir and just monitor the blichmann thermo on my pot. Thoughts?

As an aside, with those of you using pumps, where are you controlling your recirc volume so you don't compress your grain bed, the pot ball valve or the pump output valve?

I appreciate the help.

Click to expand...

I don't think stirring the top layer of your mash is going to be a problem. If you look at Blichmann's Manual for their Autosparge it says:

"Tip: We do recommend that you periodically rake the top 1/3 of the mash during lauter about every 15 min to maintain a smooth efficient lauter process. Raking the top of the mash will not disturb the lower
part of the grain bed and the wort will remain clear throughout the lauter."

Definetly control your flow from your pump output valve as recommended above. I have a Tower of Power and Blichmann recommends you wait 10 mins (as eastoak stated above) after doughing in before you start recirculating. I know all to well from experience, if you don't do this, you will get a hoplessly stuck mash. If you are using their false bottom, they have recommended max recircluation rates. For the 15 gal pot it is 1 gpm. If you don't have a flow meter you can run a test and determine where the handle on your valve needs to be to give you the 1 gpm flow rate. Of course this is just an approximation. One of the ways to monitor your mash as you are recirculating is to monitor your sight guage on your boil pot. If the liquid level starts falling too far to the bottom of the sight guage, your are probably recirculating too fast. I try to keep mine in the top third of the sight guage.

I use the a Blichmann Pot for my mash tun. Once I dough in, I now actually wrap the mash tun in 4 layers of reflectix and wait 10-15 minutes. Usually the temp doesn't move more than .5 degrees. At the end of 10-15 minutes, I start recirculating with heat. Of course you have to remove the reflectix before you turn the burner on.

My two cents.

eastoak said:

i had it on my tun but ended up removing it. the keggle holds heat remarkably well, grain ended up getting under the reflectix and getting yucky. with direct heat i didn't think it was worth the trouble. it does shrink and melt with continual heat. what i started to do was heat the water in the hlt then add it to the tun so that the burner would only be coming on occasionally to maintain temps.

Click to expand...

I made a jacket with 3 layers of the reflectix insulation and used the aluminum? tape to hold the jacket together and velcro to secure it to the MLT so I could remove when I wanted. I folded the tape over the top edge so no liquid or wet grain could get between the layers and get funky

Recirculation during the mash does have an inherent cooling effect. Using a direct fire configuration I would monitor the grain bed temp and the output of your pump during recirculation to determine average wort temp between the two. During a 60 min mash I will do a thorough stir at 30 min as I have found it helps increase my efficiency. 30 min is plenty of time to re-set grain bed and get crystal clear wort. I recirculate the entire mash and add heat via a HERMS. I’ve found I get best overall results by keeping the rate at 1gpm or so with the keggle and false bottom and 2.5gpm on my 40 gallon mash tun.

Alright - here's what happened:


1) I always condition my grains; I used to use a HLT to warm all water for the brew day. I decided to warm the mash water in the mash tun to reduce the equalization time (to warm the metal kettle).

2) I doughed in and let the grain settle for at least 15 mins before activating the pump. Since I preheated the MT, the drop in temp was much more predictable. I was experiencing a 1deg loss in temp for every 10 mins or so. Really, since I overshot my target temp by 2 degrees and I waited until I was short of my target by 2 degrees before heat and recirc; I didn't touch the mash for 40 min.

3) After recirculating for the last 20 mins or so, I transferred to my BK. When I scooped out my grains from the MT, it was a very fluffy grain bed - perhaps the lightest I've ever seen. I was recirculating wide open on my ball valve and wide open on my pump output valve.

4) All flow was controlled from the pump output valve. This worked very well.

So...thanks for the tips, they worked flawlessly. I'm very happy with my new processes - I've done two batches hitting my numbers exactly and with the same mash texture both times.

Thanks HBT for all the help.

Does anybody else get a whining loud pitch sound from their pump during the boil? I’ve recently started getting one. Seems to stop if I slow the flow rate way down through the pump but has on occasion persisted to where I’ve had to cut my boil short.

If you are trying to recirculate during an actual boil, the pressure drop induced by the pump can actually cause hot wort to emit steam where it causes pump head cavitation and if bad enough a total stall.

If you're determined to recirculate during a boil you have to dial down the flow rate to avoid that negative pressure on the kettle output.
fwiw, once my BK is within a few degrees of 212°F I shut down the pump as there's not really any good reason to recirculate during the boil and if I were to persist the pump would eventually complain loudly as its rotor cavitates...

Cheers!

That makes sense. I always heard it’s good to run the pump in the last 10 min of the boil to sterilize the plate chiller. If you aren’t running the pump to do this, do you worry about contamination?

When I use my PC I hook it up while I'm heating my strike water in my boil kettle (sparge liquor is heated separately in the hlt). As I'm bringing the strike water temperature up to around 165°F the PC would be exposed to sanitizing temperatures and time well in excess of that dictated by pasteurization temp vs time charts. So that's a done deal before I've even struck the mash

fwiw, for my IC (which sees way more use these days than my PC) I drop it in the kettle in the last minute or so of the boil. The pasteurization time at 212°F takes a fraction of a second, so giving it a minute or two to fully heat up to boiling temperature is plenty...

Cheers!