I usually recirculate my mash by pumping from the valve on my mash tun and pump over the grain bed that is usually covered in a few inches of wort. This sometimes creates a compacted mash, and I worry that I'm not extracting as much as I could. I've been thinking of reversing the flow of the recirculation. By pushing liquid from the bottom of mash through my manifold I would keep all the grains suspended in liquid. On top I would use another manifold to suck in just liquid. Before the sparge I would the reverse flow and set the grain bed and proceed with a fly sparge. Does anybody do this, and has it worked out ok?
Recirculating mash question
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McKnuckle
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Google the Speidel Braumeister and watch a couple of videos of it in action after mash-in. It is designed to do exactly that (it's really cool). Only difference from what you describe is that the flow does not reverse at the end. The grain bed is very nicely set and you just pull the malt pipe (as they call it) out of the kettle for draining and an optional sparge.
Brewvy
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I'll lay my old manifold on top to filter out the grains.
brewmadness
Well-Known Member
I've always wondered how recirculating doesn't compact the grain bed so tight it restricts or blocks flow as well. I get a pretty firm compaction just doing a batch sparge!
I have a 2 Vessel electric system where I do a full volume mash and I gravity drain from the mash tun. I just have a line of tubing that goes around the top of the grain bed and keep's the top couple of inches moving and haven't had any issues. My false bottom also only covers a portion of my mash tun and not the entire thing. I still get clear wort into the kettle after recirculating for an hour.
HTH1975
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Unless you have the valve fully open, you shouldn’t get a compacted mash. Maybe try knocking back your flow rate.
The problem with reversing the flow is you will disturb the grainbed that has formed in the mash and your wort will run cloudy with bits of grain. I don’t see any benefit in doing this.
I've actually never had a stuck mash. I'm just very slow and careful during recirc, and at the beginning of runoff.
Brewvy
Well-Known Member
I guess I'm wondering if the extraction would be greater by circulating the mash liquid in a manner that would keep the grain more in the solution rather than setting up a grain bed. I don't get stuck sparges, but I'm wondering if the flow of liquid channels through thetgrain bed and doesn't givee the greatest extraction. I usually get between 70-75%efficiancy.
I would expect the fluidity of the grain bed would immediately lead to a plugged manifold. It is exactly why one should let the mash rest for at least a few minutes after dough-in to allow the bed to settle and build the "scaffold" that forms the filtering that leads to clear wort. A highly fluid bed is unlikely to build the structure that leads to effective filtering, and manifolds are prone to plugging given the dramatically lower open area compared to a false bottom...
Cheers!
Cheers!
Best thing I did when I started (20+ years ago, though a lengthy hiatus till couple years ago) was to get very finicky about an exceedingly slow runoff. My 10 gallon batches take about 90 minutes. I start at the tiniest trickle and increase as the wort begins to lighten up. This aids in avoiding not only compression and a stuck mash, but localized channeling as well; all of which tank efficiency, as you know. My runoffs are always very clear and my extract is high enough for me. Just looking at my last brew, I got 90%.
I also run a long "Granton-edge slicer" (just a knife, used for thin slicing e.g., smoked salmon) through the mash, "knifing" I think it's called, which is my best means to approximate a mash rake. At our level I'm not sure how much it helps but I do sense a "lifting" of the grain of bed, and see an even bed throughout, no channels. You have to be sure to stay well off the bottom in my experience, or you'll disturb the lauter and get cloudy runoff. I typically just go slowly down, straight, then pull back about 3". Then I run very even, steady slices at 90 deg., something like the strip crust of a French apple pie.
Oops, I missed the manifold. I've never used them but they can be tough, from what some friends have told me. Thanks for the explanation trippr. Fascinating.
Edit: By dough-in, you're talking about the traditional dough-on to get the grain solubilized, or the entire mash mixed in and settle? (I never do a dough-in like, say, explained by Greg Noonan. So am not familiar with how people use the term).
Also, with a manifold, is there any use to - can't remember the term, not underletting as in during a stuck mash but the small amount of water added before adding grist to "float" the initial mash?
Dough-in is the simple act of mixing water and grain in the tun. There are a few ways of accomplishing that - add the strike volume first then mix in the grain, add the grain first then pour the strike volume on top, and finally adding the grain then underletting the strike volume (which is what I do).
The term I think you're referring to is "foundation water", which traditionally meant filling the mash tun with just enough of the strike water to cover the false bottom, before adding grain and then introducing the rest of the strike volume. This was intended to prevent grain dust from caking over the false bottom like a batter, and the technique might well work with manifolds used in the traditional manner...
Cheers!
The term I think you're referring to is "foundation water", which traditionally meant filling the mash tun with just enough of the strike water to cover the false bottom, before adding grain and then introducing the rest of the strike volume. This was intended to prevent grain dust from caking over the false bottom like a batter, and the technique might well work with manifolds used in the traditional manner...
Cheers!
Thanks Trippr. Foundation water, that's it. On the doughing in, I think I saw it in Noonan or somewhere, a truly arduous task where you're adding only enough water to literally make dough, you work it to make sure it's fully wettened before adding the remainder of your strike water. I think it might be a traditional German thing to avoid dough balling up. But this is all very sketchy. I've just never had a problem with balls, just keep working in until everything is mixed as far as I can tell, and temps are usually great.
Edit: Yeah, it was Noonan. Basically your grist goes in a separate vessel. You add the grist in, then begin sprinkling some water in, kneading it in, repeat, until the grist is saturated and cannot take on more water. You are trying to avoid balling but more, you're trying to evenly solubilize the enzymes, "fully dissolve the endosperm including the enzyme-rich particles of the aleurone layer."
Various regimes described, important to remain thick, with the hotter the water you use, the more careful you need to be to dough in properly.
I've seen a lot of descriptions that talk of basically mashing in fully at some sort of an acid/phytase rest. But that's not what I remember as "doughing-in." I don't know that an acid rest is needed in any malt anywhere anymore, is it?
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augiedoggy
Well-Known Member
I believe gravity is also working against you in the same fashion as it works for you meaning the wort may not consistently flow upward evenly throughout the grainbed but rather channel.. Honestly I may be wrong on that though.. Its similiar to how a phosphate (or any) reactor in a salt water aquarium works.
one caveat to underletting is it doesnt seem to work too well in larger systems.. We have tried it multiple times on our 3 bbl setup and the mash temps at the top end up being as much as 10-12 degrees lower on the top as they are on the bottom of the mashtun due to the strike water continuously cooling from the grain bringing it down as it travels through it up to the top. Otherwise it works great. This wont be an issue when homebrewing and makes it an excellent choice for smaller batch brewing.
augiedoggy
Well-Known Member
What is your flowrate? your kinda guessing unless youve somehow measured it, flow meters are great for this and there are inexpensive ones which will show you when you have flow issues or how much restriction things like oats or wheat are adding to change your flow rate. I use one and recirculate at between 1.5 and 1.8 gpm consistently and average 91% brewhouse efficiency on my 3 vessel setup. I never use rice hulls either.
I've been using the underletting method for over a year now, and won't go back. Strike goes in at 168-170, and I consistently get mash temps of 152-154. I let it sit for 50 minutes after dough-in, and only recirculate for the last 10 minutes of the mash. I've got a ball valve on the tun and only open it about 1/3 of the way for lautering and first runnings, don't open it full flow until draining out the sparge. Haven't had a stuck mash yet with this method, and I'm getting pretty clear wort out of it. My tun is a repurposed 16g extract barrel with a pex-pipe sparge arm attached to the lid with holes drilled in it, works great.
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