Full Volume Mash 3 Vessel

[sicktght311]

Whilst cleaning and setting up my electric system over the weekend, i was looking at my HLT without the herms coil installed yet, and i had a thought, and wonder if anyone has ever tried this.....

No Sparge Full Volume Mash has become popular nowadays with the BIAB people, who see no massive reduction in efficiency, and enjoy the quicker brew day due to the lack of sparging, however with a 3 vessel system, we're heating water and controlling it's temp with an electric element in the HLT, and using the herms coil to control the temp in the MLT. Whats to say you couldn't ditch the Herms coil, use the full water volume for your brew day, and balance the sweet wort it between the HLT and MT, using the element in the HLT to maintain wort temperature as it gets recirculated between the two vessels.

Brew day starts with say 8 gallons of water in the HLT, heated to your strike temp, you transfer all of that over to the Mash Tun and dough in, let it rest for a couple minutes to soak the grains, and then start your pump to drain 3-4 gallons of wort back into your HLT, covering the element, and start a traditional recirculation between the HLT and MLT keeping an equal in/out flow to maintain the same volume in both vessels, and use your controller to fire the element to maintain a constant mash liquid temp. With the wort constantly recirculating it continuously keeps the grains at a constant mash temperature, you're vorlaufing as you go, and then when its time to mash out, you simply raise the temp, recirc for another few minutes, and then move the outlet of the HLT, to the recirc of the MLT, and the MLT outlet over to the boil kettle, and your sweet wort from both kettles filters through the grain bed and out to the BK

I'm sure i'm missing something in my thinking, and perhaps this method would hit efficiency somehow, but in my brain, it seems pretty reasonable, no?

Realistically, this could even be paired down to a 2 vessel system, and the BK can substitute as the HLT and vice versa

 

[Wizard_of_Frobozz]

I think this type of system is referred to as a "Kettle RIMS". It will work - it's basically the same as a RIMS, but the heating element is in the bottom of your kettle instead of in a tube. You just don't get the ability to change your mash thickness across different brew sessions. You might have more potential for hot side aeration, but that can be dealt with by good system design (keep your recirc return below the surface of the liquid in the kettle and in the mash tun).

I don't think that efficiency is the only concern when comparing full volume mashes to traditional mashing. Grain-to-water ratio plays a role in the conversion process. Thick mashes tend to produce more dextrinous wort, thinner mashes give you more fermentable sugars.

I chose a 2V setup (with external RIMS) over BIAB mainly because of the ability to play with mash thickness. If I want a low alcohol session beer, I'll go thicker on the mash. If I want something stronger, I'll go thinner.

 

[postalbunny]

What you're describing is more of a RIMs setup where you're using the entire HLT as a rim's tube since the "wort" will be in contact with the HLT coils to maintain it's temp. When dealing with RIMs the size of the tube affects how fast you can heat and how much larger your mash thickness needs to be to account for the extra tubing/equipment. For a HERMs you only need extra volume of water to populate the herms coil and tube, with RIMs you usually shoot for a 1.5 or 2" tube and the extra volume is only what you need to fill that. Anywhere between 1.25 and 1.5 and you really don't have issues with thickness on 5g or 10g batches in 20g kettles or 15g "keggles".

This setup with describe the HLT heating means you need enough "wort/mash" water in the HLT to cover the element. On a 20g kettle this will likely be 3-4g mark. Then you need to turn that water volume over enough to make sure you're maintain heat in the MLT and have enough water for at least 1.25 qt/g thickness. IMO ,this won't work out as well as expected on our volume (5-15g batch volumes). If you were doing larger size batches then the volume you're maintaing in the HLT wouldn't matter as much. You would probably be better off just ditching the herms/rims part and building some insulation around the MLT and doing simple plain infusion mashes until you can get the herms coil.

You also lose the ability to "sparge" ... you're water and wort would essentially already be mixed and you'd be doing a single no-sparge technique. To combat some eff loss when batch sparging you usually do 2 runs... you drain once, start heating BK and then mix your 2nd "batch" for 10-15mins and drain again. Batch spargers report slighly less eff, but not by much (80 vs 85 etc). Your efficiency would likely suffer a bit due to this, brulosophy did an episode where they did no-sparge vs batch and reported a 3% hit on the no-sparge. Another episode of fly vs batch sparge showed a 5% hit to eff on the batch sparge. I know they're not all 3 compared in the same episode, but you could expect 8-10% eff drop between a fly sparge and a no-sparge. This isn't the end of the world, you can always just add more grain and calc yoru recipes based on the actual eff you get; but if you're going to spend money on kettles/elements/etc I don't think i'd give up that eff unless you were trading something valuable for it. I think you're going for less complicated by having no herms coil, but in the end i think you'll realize this setup doesn't exist much in the wild because it's actually more complicated.

You'll also lose the big advantage HERMS and RIMS has over other setups in that the HLT is always clean... and by running sparge water through the coil it stays pretty clean as well. When cleaning I usually only have to run pbw/acid through my MLT and BK on brew days. I simply drain the HLT and dry, every 3-6mo run some PBW through just to catch any build up i may have missed.

You can still play with this setup even if the coil exists, just to see what happens. My bet is that the mash ends up in 60-70% eff range vs the 80-85% due to the extra water flying around and less contact time with grain. Then you have to clean both the HLT and MLT since you got sticky wort touching everything. The savings in money on the coil, and complication of 2 compression fittings will likely be negated by the negative brewing experience of extra cleaning and bad efficiency.

 

[sicktght311]

For the record, i'm absolutely not doing this kind of setup as i'm fully on board for 3 vessel herms haha. My herms coil should be here today or tomorrow, and i've already got everything else on order, or plumbed. I was just thinking out loud as I thought of the idea

 

[postalbunny]

Gotcha... well, then carry on Always good to ask questions....

 

[Elky]

Brew day starts with say 8 gallons of water in the HLT, heated to your strike temp, you transfer all of that over to the Mash Tun and dough in, let it rest for a couple minutes to soak the grains, and then start your pump to drain 3-4 gallons of wort back into your HLT, covering the element, and start a traditional recirculation between the HLT and MLT keeping an equal in/out flow to maintain the same volume in both vessels, and use your controller to fire the element to maintain a constant mash liquid temp. With the wort constantly recirculating it continuously keeps the grains at a constant mash temperature, you're vorlaufing as you go, and then when its time to mash out, you simply raise the temp, recirc for another few minutes, and then move the outlet of the HLT, to the recirc of the MLT, and the MLT outlet over to the boil kettle, and your sweet wort from both kettles filters through the grain bed and out to the BK

You just accurately descrbed a kettle-RIMS, with one point missing. When you're doing Kettle RIMS, you don't need a third vessel. The 'HLT' that your heating element is in doubles as your boil kettle. When you're done with your mash, you just kill the pump going back to the mash tun so that the mash tun drains into the kettle and boom, you're ready to start your boil.

I just built one of these a few months ago and I love it. I decided that the cost savings, the smaller footprint, and the shorter brew day was worth the minor tradeoffs from a 3 vessel system.

You'll also lose the big advantage HERMS and RIMS has over other setups in that the HLT is always clean... and by running sparge water through the coil it stays pretty clean as well. When cleaning I usually only have to run pbw/acid through my MLT and BK on brew days. I simply drain the HLT and dry, every 3-6mo run some PBW through just to catch any build up i may have missed.

You can still play with this setup even if the coil exists, just to see what happens. My bet is that the mash ends up in 60-70% eff range vs the 80-85% due to the extra water flying around and less contact time with grain. Then you have to clean both the HLT and MLT since you got sticky wort touching everything. The savings in money on the coil, and complication of 2 compression fittings will likely be negated by the negative brewing experience of extra cleaning and bad efficiency.

FWIW, since you don't actually need a 3rd vessel you don't have anything extra to clean, just the MLT and the HLT/BK. Also, I'm only 3 batches in but I'm getting about 75% efficiency on mine. Not as high as the 80-83% I had with a cooler mash tun and single batch sparge, but high enough that I'd not spending any significant amount more on my grain and I expect to bring that number up as I further dial things in. As long as it's consistent I'll be happy.

 

[postalbunny]

Good point... if you go down to 2 vessel setup there wouldn't be an "HLT" to clean if you use it as the BK. Then the only issue would be having enough volume to cover an element in the hlt/bk. If you're only down to 75% eff as a result of an unltra thin mash then it may be worth the trade off since you'd be saving an entire kettle's cost and not just the herms coil cost. I can't speak to how the efficiency would suffer due to mash geometry changes and basically no-sparging. It's interesting to hear Elky still able to get 75%. I may try a round on my next beer of just mashing with the full volume and straight no-sparge to see what the eff is.

Of course, without that 3rd kettle you can't double batch or keep any spare hot water around. But most homebrewers probably don't bother double batching; i do it often to test two variables like mash temp or boil addition timing.

 

[Elky]

Good point... if you go down to 2 vessel setup there wouldn't be an "HLT" to clean if you use it as the BK. Then the only issue would be having enough volume to cover an element in the hlt/bk. If you're only down to 75% eff as a result of an unltra thin mash then it may be worth the trade off since you'd be saving an entire kettle's cost and not just the herms coil cost. I can't speak to how the efficiency would suffer due to mash geometry changes and basically no-sparging. It's interesting to hear Elky still able to get 75%. I may try a round on my next beer of just mashing with the full volume and straight no-sparge to see what the eff is.

Of course, without that 3rd kettle you can't double batch or keep any spare hot water around. But most homebrewers probably don't bother double batching; i do it often to test two variables like mash temp or boil addition timing.

Yeah, you do lose some flexibility when it comes to double batching, but I thought about it and realized that I've only ever done it twice in 10 years of brewing before going electric, and that was when I was brewing 5 gallon batches. I'm lucky that I have a hot water line right over my brewing area so I just Tee'd into it and can fill an extra bucket/pot with 140 degree water if I need it for cleaning.

I've been able to get 75% by conditioning my malt and making sure to have a mashout step before taking everything to the boil kettle. It shouldn't be very surprising, people have been getting pretty solid efficiency with BIAB when recirculating, and with a K-RIMS you actually keep the proper/traditional grist ratio in the mash tun which I've heard is really what matters.

 

[augiedoggy]

More than 80-85% is entirely possible with a 3 vessel system. I average 91%. While I agree the brewing costs aren't significantly different it really all depends on the brewers point of view... I hear some brewers turn down even considering electric because of cost. At least with equipment its a one time cost and your done. if someone brewed every other week that 15% efficiency would add up in a year. Of course if I didnt have the space to leave my equipment setup I would likely also be using some form of biab myself.