2 pot Contra-Flow RIMS?

Hi all,

I'm a newbie to brewing but have been doing lots of research on All-Grain brew systems so i can eventually build my own. I have come up with some ideas that should reduce the number of pots and therefore space required for the system to operate at the same time as keeping efficiency as high as possible and I'd like some feed back from you chaps!

Basically there are 2 pots, a boiler to heat the liquor and do the wort boil and a mash tun with a recirculating pump that will work backwards during the mash ie take wort from the top of the grain and put it back in though the false bottom.

Heres how i envisage the set up working in more detail- (pls excuse my metric-ness!)

1 - Lets assume for example; i want 25 liters of boiled wort for the FV, 5 liters will be lost to the grain and 5 liters will be lost to the boil (closer amounts will be calculated when i done some practice runs). i fill the boiler to the 35litre mark and heat it to circa 80degreesC (some experimentation needed here).

2 - I then pump the whole 35liters into the Mash Tun add the grain and check it is at the 66degress or so i am looking for. The idea behind adding the whole amount of liquor now rather than keeping some back for sparging is that by keeping the sugars moving and the dilution higher, one should be able to extract more of the sugars i.e. keep the efficiency high, it also should help me be sure i will have the right volume in the FV after the mashing and boiling.

3 - I then start the recirculation pump; this will take wort from the top of the grain mass (via a simple filter) and return it to the false bottom. The idea behind this is to keep the finer bits of mash away from the false bottom and thereby aid the clarity of the wort to the FV and prevent blockages of the false bottom screen. Also by not sparging in a traditional manor, i am able to use the boiler after the mash for the boil. I am thinking about having half the mash time recirculating backwards and then reverting to bottom to top recirc in preparation for draining and cooling.

4 – After the mash, I pump the wort back to the boiler for the boil.

Simples!

I would appreciate feedback guys! Am i heading for a fall here? Or do i sound like i might have something worth trying?

Cheers guys!

Steve

I think you will only do slightly better than a single batch sparge because you are recirculating. Honestly though, I don't see the benefit of recirculating from top to bottom. If you push up you are going to free all of the fine bits that have been compacted into the grain bed and suck them out the top. I imagine you would have a gigantic mess under your false bottom by the time you are done recirculalting.

I haven't had my RIMS system stick a sparge yet, and if I suspect it might I would add rice hulls. I just start slow and allow the grain bed to set up and compact. After several minutes I can crank it wide open with no issues. Generally I leave it at about 40% because my RIMS heater seems to like it there.

minus the reverse circulation it is very close to the Brutus 20. The only difference is a portion of the volume is left in the boil kettle so you can hit your temps during mashout.

Actually any batch sparge is going to be more efficient than no sparge, all things being equal. Any equilibrium of sugar water that is drained will leave behind sugar in the grain itself. That amount works out to about 1/2 quart per pound of malt. The amount of sugar left behind depends on the malt bill.

Example: 20lbs malt would produce about (20x35) 700 gravity points. If you mashed with 10 gallons, the wort would be 1.070 in the tun. However, upon draining, about 10 quarts of that wort would remain locked up in the grist. The total gravity points in that wort is 175 (or 2.5 gallons of 1.070 wort). It doesn't matter how well the circulation went on. That's the math.

Contrast that with a batch sparge:
20lb mashed with 6 gallons (wort is still full of 700 gravity points). However, it's at 1.116 concentration. You'll drain out about 3.5 gallons and leave 290 gravity points in the grist. However, now you put 4 gallons of sparge in there and stir to equilibrium. Now the concentration is at 1.044 (that's 290 GU divided by 6.5 which is the absorbed plus sparge volume). When you drain that, you'll get 4 gallons of 1.044 out and leave only 2.5 gallons behind. 2.5g x 44GU is 110.

It's certainly not a huge difference, but you should be aware of what you can expect out of a no sparge system. The recirculation aspect is great for temperature and clarity, but not much for efficiency.

Bobby_M said:

Example: 20lbs malt would produce about (20x35) 700 gravity points. If you mashed with 10 gallons, the wort would be 1.070 in the tun. However, upon draining, about 10 quarts of that wort would remain locked up in the grist. The total gravity points in that wort is 175 (or 2.5 gallons of 1.070 wort). It doesn't matter how well the circulation went on. That's the math.

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The problem with that math is NO grist holds 25% to absorption. Additionally, even if it somehow did, you've still got 30 quarts of 1.070 wort.

EccentricDyslexic said:

3 - I then start the recirculation pump; this will take wort from the top of the grain mass (via a simple filter) and return it to the false bottom. The idea behind this is to keep the finer bits of mash away from the false bottom and thereby aid the clarity of the wort to the FV and prevent blockages of the false bottom screen. Also by not sparging in a traditional manor, i am able to use the boiler after the mash for the boil. I am thinking about having half the mash time recirculating backwards and then reverting to bottom to top recirc in preparation for draining and cooling.

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This sounds totally bass ackwards. Why would you want to keep he finer bits from the false bottom? You do realize that by recirculating from under the falsie and returning the wort to the top, within 10 minutes you will have crystal clear wort, right?

How would doing a normal recirc cause a blockage of the false bottom? This is the same way that you sparge, by running the wort out through the false bottom.

There is absolutley no reason, or benefit, to pulling wort from the top of the grain bed and pushing it up under the false bottom. What you will gain though is an overly complicated brewing rig, with more steps in the process for no net gain.

Jkarp, Your grain doesn't absorb 1/2 quart per pound? What are your numbers? Most people that quote their absorption rate have said .125 gallons per pound and that's what I measure regularly on my system.

Also, I'm not suggesting any merit in either sparging or not but just correcting the statement that a no sparge system is more efficient than sparging.

Bobby_M said:

Your grain doesn't absorb 1/2 quart per pound? What are your numbers?

Also, I'm not suggesting any merit in either sparging or not but just correcting the statement that a no sparge system is more efficient than sparging.

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Mine absorbs 1/2 qt per pound...

I just re-read the OP...

You plan to do half the mash with a reverse recirc, and the other half with a conventional recirc? If I understand that correctly. That makes no sense to me, although I am a simpleton... it seems if recircing in the opposite direction has any value, that doing it only half the mash would negate any gain that you presume you will get.

Also, I have to ask what you are considering "high efficiency"? With a no sparge, simply diluting the mash with the full volume and no sparging, you will probably see a max of 70% eff... others may have better #s, but I cannot imagine anything higher than 70%. This is pretty average.

I dont see a single gain in this setup on the fronts of simplicity or efficiency. Bonus would be the 2 kettle system... but that is the only gain I see from this. This would be like a Brutus 20, right?

Hi all, many thanks for all the reply s, as i said, I'm a newbie and am just floating ideas about. I thought the revers flow would help keep the wort moving through the grain and help extraction by removing the sugar from in between the grains rather than letting it sit there. I thought that by doing this and keeping the wort between the grain more dilute, this would promote more infusion of sugars from the grain? I hadn't really considered the issue of turbidity of the final wort, so that defo is an issue.

Ok lets scrap the reverse flow and stick to RIMS but with the full amount of water in as strike. I am still not understanding why sparging is so important...surely the recirculation is doing the sparge job only not just for 20mins?

To achieve strike-like functionality, how about raising the temp of the recirc wort to sparge temp for 20mins following the 1hour mash time?

Please continue to point out the errors in my thinking!

Thanks for all the advice guys!

Steve

EccentricDyslexic said:

Hi all, many thanks for all the reply s, as i said, I'm a newbie and am just floating ideas about. I thought the revers flow would help keep the wort moving through the grain and help extraction by removing the sugar from in between the grains rather than letting it sit there. I thought that by doing this and keeping the wort between the grain more dilute, this would promote more infusion of sugars from the grain? I hadn't really considered the issue of turbidity of the final wort, so that defo is an issue.

Ok lets scrap the reverse flow and stick to RIMS but with the full amount of water in as strike. I am still not understanding why sparging is so important...surely the recirculation is doing the sparge job only not just for 20mins?
To achieve strike-like functionality, how about raising the temp of the recirc wort to sparge temp for 20mins following the 1hour mash time?

Please continue to point out the errors in my thinking!

Thanks for all the advice guys!

Steve

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You are wrong here.

Compare your mash, to a sink full of soapy laundry. The soapy water is your sugar wort, the laundry is the grain bed.

Now imagine simply draining the soapy water from your laundry, no rinse, just drain. How much soap do you imagine is in your laundry compared to rinsing it?

There is absolutely no comparison between a diluted mash, and a sprage, when it comes to rinsing sugars from the grain bed.

Recirculation, also doesnt change eff. really... it simply hellps keep temps homogenous and clarifies the wort. Recirculating also does not rinse your grain bed, it just recirculates your "soapy water" through your "laundry"

Ok, so a sparge is a rinse in effect?...so it doesnt remove any more sugars from the grains just from the gaps around the grains? is that correct?

Ok, there seems some sense in that. How about(still trying to stick with the 2 pot system here) mashing for an hour at 151degreesF with enough liquior to cover the grains by an inch, then recirculating to just till the wort is running clear, then(after an hour has passed) pumping the sparge liquor (which i will have heated to about 176DegreesF) on to the top of the grain bed without disturbing it. Then run off the first runnings over a period of 20 mins or so, the sparge water will slowly filtrate through the mash sparging as it goes. Will this emulate normal sparging?


Steve

Bobby_M said:

Jkarp, Your grain doesn't absorb 1/2 quart per pound? What are your numbers? Most people that quote their absorption rate have said .125 gallons per pound and that's what I measure regularly on my system.

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You're right, of course. Ignore me. I was drinking. :cross:

I do all my calculations in gallons and the quarts bit threw my impaired mind. My absorption is also around .125 gal/lb.

As much as I hate to admit it. Pol's analogy is dead on. The sparge step can not be omitted if you want to take all the sugars from the grain. Sparging is a centuries old, time tested method of rinsing all the sugars from the grain. Every commercial and almost all homebrewers do some sort of final rinse of the grain to get as much of the sugars out as possible. If you don't believe us, build your system and try brewing a beer.

you should look at this build sizz built a 2 pot system and he can still sparge.

Shameless self promotion:
Check out the last post on the second page and the first post on the third page of this post.
Also, this thread. It's all theoretical, but it sounds like that's the stage you're at as well.

Steve, my first post explains why sparging takes more sugar. Grain absorbs liquid, whether it's water or wort, at a rate of about .125 gallons per pound. I don't know what that is in liters/kg. When you have your mash or recirculated no sparge mass of grain and wort all homogeneous, the grain has a pretty substantial portion of wort locked up. All sparges work because of the principal of diffusion. Try this analogy.

Dunk a dry sponge into a pot of sugar water. Remove the sponge and drop it in a pot of regular water. Given enough time, the sugar concentration of the water in the pot and the water that was in the cells of the sponge will reach equilibrium. That's a sparge.

People always want to change the status quo...

There are some things that are difficult to improve upon though, like sparging.

I have nothing to add, just build it, let us know how it all turns out.

The Pol said:

People always want to change the status quo...

There are some things that are difficult to improve upon though, like sparging.

I have nothing to add, just build it, let us know how it all turns out.

Click to expand...

whoa brother. Can't imagine what you thought of my electro magnet stir plate idea (which I am going to build for giggles) :cross:

Just ignore my 48 bottle force carbonation rig build thread coming up. j/k

Still plan on building it, and maybe play around with contra flow, see what happens.

No one has given their thoughts on the idea of doing the mash then topping up the MLT with the sparge volume at the slightly higher temp and then staring the mash out very slowly. Basicaly you would be positioning the sparge volume above the mash and slowly draw it through, just like a sparge does, just all in one go. Any thoughts on this?

Steve

The extra weight of all that water MAY compact the grain bed a little more than usual. Give it a try.

Bobby_M said:

The extra weight of all that water MAY compact the grain bed a little more than usual. Give it a try.

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yeah, I would be interested in seeing how that works out. Would be a good solution to my sparging solution.

btw, thanks for clarifying the difference between batch sparging and no sparging. I was the one who started that tangent.