Corn mash + false bottom. Bad idea?

[Prospekt]

I'd like to convert one of my kegs into a brew kettle. Ideally with a false bottom/screen and a ball valve so I can cook, mash, and drain off the corn worts in the same vessel. And, yes, this means I'm moving away from fermenting on-grain.

Has anyone tried using a standard perforated SS false bottom screen with a dip tube for all-corn-mashes? I suspect there will be problems...not only with heating, scorching, and gumming at the false bottom when boiling up the corn before malt addition, but with the grain bed getting stuck as well.

[Boda Getta]

I've thought thing, I would think the risk of scorching would be lessened because the solids would be held off the bottom at the heat source Do you have an idea of what to use as the screen? Brew shops sell SS perperated screens for mash tuns but they are pricey
BG

[shadylane]

My experience with a false bottom is the grain bed getting stuck almost instantly.
Haven't tried putting a fire under the mash tun with a false bottom in place.

[Jimbo]

Windy City has done this with bourbons and oat stuff. Doing constant recirc with a pump and mash heater. He had great luck, couldnt believe it. Maybe he'll chime in with some details.

[Prospekt]

I was thinking that I might need to recirculate with some kind of chugger pump. The problem though I think would be that the pump might not be able to handle the gravy-like consistency of the corn before the enzyme addition.

[Prospekt]

My experience with a false bottom is the grain bed getting stuck almost instantly.
Haven't tried putting a fire under the mash tun with a false bottom in place.

Shady, were you using a fine grist or cracked corn? I'm generally using feed corn which is pretty chunky, but I run it through the mill once to get some of the large pieces to open up a bit.

BG, I think I can source a "sample" perf SS sheet from a local shop for a bit cheaper than the false bottom kits. I'd have to cut it nice and round and put legs on it, but they have the hole-size I've seen advertised in keg conversion kits.

[MitchyBourbon]

Windy City has done this with bourbons and oat stuff. Doing constant recirc with a pump and mash heater. He had great luck, couldnt believe it. Maybe he'll chime in with some details.

This is exactly what I do. I have a 10 gallon blichmann boilermaker, March pump and blichmann chiller. When mashing just the corn (before adding malt) there is absolutely positively no way to recirculate. It is just plain too thick. Once you add the malt and it thins out a bit it is possible. I mash with 2 lbs cracked corn (no extra grinding) per gallon of water. I use a 2000 watt hot plate to maintain a boil and a 25 gallon milk can with 5500 watt internal heating coil to produce my strike water. The amount of malt I use varies from recipe to recipe. On average it totals to about 2.5 lbs of grain per gallon water. I still squeeze the grain after mashing my last batch of the day using a janitors mop bucket. I sparge the other batches and use the spare water for the next batch. I typically do three batches, it makes for a long day but my results are always very consistent.

I have considered using rice hulls but once the corn gets thick it can't be circulated. You have to stir it and the rice hulls would just get mixed in with the corn.

[Windy City]

I am using a modified 55 gal Blichman pot. I modified it by installing a 3/4" pick up instead of the stupid 3/8" they supply with the pot. I also had about 20 1" tall legs welded to the underside of the false bottom to increase my liquid level and reduce the risk of boiling or scorching. My electric brewery is not complete yet so I am heating the mash tun on a banjo burner and am recirculating with a march nano brewery pump.
I recently made some breakfast bourbon (52% flaked maize and 48% rolled oats) I added 3 pounds of rice hulls per 100 pounds of grain, if I recall correctly I think I used about 110 pounds of grain in this recipie. I am converting my grain bill with Specialty Enzymes high temp and low temp enzymes.
I heat my strike water to about 205 f, stir in my grains and then add the Sebbrew HT. At this point if I wasn't to pokey I should be at 190f. I will let it sit till it drops to about 185f give it a stir with a long paddle to loosen up the bottom then turn on the pump and slowly open the valve until I get the flow I want. Once I have a good flow I will start the burner on very low (it really doesn't need much). Nothing is automated at this time so I really need to keep an eye on it. The enzymes work pretty fast and do a great job of chewing up the starches making it even easier to pump as time passes. Approximately every half hour my flow will start to slow down and I have to mix up the bottom with the paddle to restore full flow. When I am done with the high temp I throw an immersion chiller in until I reach 146f and then add the Seb Malt Super. Again I let it do its work and then with the chiller I crash down to pitching temp
I do ferment on the grain so when I am done I pump the wort into my fermenter and then scoop and dump the grain in.
A note about this. The rice hulls help a lot but the enzymes are really key to loosening everything up. Also when I first modified The false bottom (raising it) it crated a small gap around the perimeter which caused all sorts of problems. I fixed this with Jimbo's help (thanks) by attaching stainless mesh around the perimeter. It is now as tight at a ducks butt and no grain can pass through
Hope this helps
Windy City

[shadylane]

My experience with a false bottom is the grain bed getting stuck almost instantly.
Haven't tried putting a fire under the mash tun with a false bottom in place.

Shady, were you using a fine grist or cracked corn? I'm generally using feed corn which is pretty chunky, but I run it through the mill once to get some of the large pieces to open up a bit.
.

Using cracked corn that was run through a bur grinder to make a coarse corn meal.

[Prospekt]

Wow, thanks for the feedback guys. I was away over the weekend and so I didn't get a chance to check on the thread.

I think this is going to be a winter project for me. From what I gather, I might have success recirculating after the malt addition. What I might try is to build a raised false bottom as per Windy City's advice. I guess the idea is to create a fairly large reservoir of liquid below the grains. And no recirculation until after the malt addition.

Once I start working on this I'll try to document it with lots of pics.

[ltrmoore]

I just did a batch of cracked corn on my system. I have a continuous mash recirculating chugger pump system. I did not start the pump until starch conversion was complete and the mash was watery again. I used like 10 gal of water and 17 lbs of cracked corn. I don't know if this would work if I crushd the corn down more through my grain crusher. I would like to because I think I would get more access to starches in a finer grind, but I'm afraid of getting a stuck sparge. I'll have to experiment

[woodshed]

Make a false bottom that pulls up off the bottom instead of through the screen out of copper pipe. Been running this way for years.
Never a stuck mash and no recirc. Easy to do. Lower costs equals happier shed.

[Fills Jars Slowly]

I think what Woodshed is referring to is what brewing texts like John Palmer's "How to Brew" (available online, but do yourself a favor and buy the revised and updated print version), call a manifold. The print version that I own has a whole appendix on manifold design as well as false bottoms and other lautering techniques. The manifold I built is 1/2 inch copper tubing all put together in a grid of sorts that sits on the bottom of the mash tun. It has slots in the underside of the tubing that filter grain from wort at the lowest point in the pot, and connects to the mash tun outlet. The difference between a manifold and a false bottom is that a manifold is much more resistant to a stuck mash. I have used one for beer brewing for years. I have not used it on my all grain distiller's beers (other than single malt) due to warnings on this forum that "you can't lauter a bourbon mash" and my fascination with a new way of doing things. To me, my Booner's mash using corn meal and enzymes looks so liquidy that I think it might go through my manifold grains and all. Will have to try it and see. The worst part of all grain distilling continues to be separating fermented wash from grains, hands down.

[woodshed]

I'll go with manifold I guess but whatever you call it bottom line it works, properly designed without the channeling it can create according to some.
A multi medal winning brewer here in town uses one because I turned him on to it years ago. GABF medals, not the county fair variety.
Although he wins for his hops every year at the fair. Gonna try and change that this year.

Look back hard enough and you will find a pic of mine in a Blichmann 55.

[Fills Jars Slowly]

That is correct. A properly designed manifold system does not have channeling problems, though it is a weakness of an improperly designed manifold type system (like with one big pipe down the middle). I have several gold medals at NHC (I am not a commercial brewer so I compete in NHC not GABF) with such a setup, and I concur with Woodshed's observations. Just wanted to point to a source that gives specifics on building an efficient manifold for those not as in the know about such techniques.

[bearriver]

Currently in the process of building a 100 gal MT with recirc and a false bottom from NorCal brewing. Its a gorgeous build so far, and am looking forward to finishing it. I'll post the pics when its done.

From what I read rice hulls will help tremendously with mashes that like to get stuck. Pulling from the bottom with a good pump should help considerably as well.

[woodshed]

That is a great source of info FJS. What I like best about the manifold it is cheap and very effective.
And no stuck mashes. And no pump, no added cost per run. When it's a business as it is for me every penny buys more corn

[Fills Jars Slowly]

Woodshed, do you sparge using your system, or just drain through the manifold/ false bottom / whatayacallit? Sparging, in my terms, would mean rinsing the grain bed with more water poured through as the mash tun drains. In brewing terms we would call just draining the pot through a device that filters out the grains "no sparge." No sparge tends to leave more sugar in the grain bed, whereas sparging rinses the grain bed at the expense of diluting the wort a bit.

[woodshed]

I would call what I do is more of a rinse. Brewed beer for years and always sparge, the all corn gets more of a rinse.
Sparge my multi grains. Barley and rye need it. Corn done properly will give almost everything first shot.
If it is sticky when you take it out you left some goodness behind.

[Usge]

I use a heavy duty mashtun that came with the standard holed stainless false bottom and drain. Cracked corn works fine and drains off fairly readily in most cases. The only thing you have to watch is higher lb per gal recipe ratios that get too thick and don't mash out properly. But, that has nothing to do with the false bottom anyway.

If you are using flaked grains...you are gonna need a brew bag big enough to line your pot. I like that the false bottom helps keep it lifted up off the very bottom of the pot and keeps the drain clear. When I'm done...I squeeze the bag against the bottom screen and stain off the liquid.

The only sparging or rinsing that I do is if I'm going to start a next round/batch...I sparge the previous grains...and use the water from that ..to help start the next batch/round. This is a trick from Dnderhead..and helps to add a point or two per round to your SG. You can also use the left over grains...to help start a sugar wash after if you want to recycle everything.

[Fills Jars Slowly]

This is my lautering system, which has not been used on a distiller's beer yet. It has slots on the bottom side and sits in the mash tun like so, connected to an outlet with a ball valve on it by a short length of hi-temp silicone hose. Never have had a stuck mash when brewing, but I use rice hulls with the ones that tend to be gummier.

bottom side: slotted

Manifold in the mash tun

[humbledore]

I've had a few badly stuck mashes with a false bottom, but that was before I was using enzymes (just malted barley). Even now that I am using them, to get the best efficiency from the corn you really have to grind the crap out of it so it's halfway to powder. And once you do, even though the enzymes thin it out pretty damn well I would be wary of doing a pump re-circulation or even just a plain old sparge/rinse and risk yet another stuck mash. So if you are taking and using cracked corn without further grinding, then it might work better. But you won't get the same efficiency with it. A lot of folks don't mind because it's so cheap, and just throw more in. I have a copper pipe manifold with slots just as shown in earlier posts. I would love to be proved wrong and get out of doing all that squeezin' to separate corn from wash.

[akwildian]

I am using a modified 55 gal Blichman pot. I modified it by installing a 3/4" pick up instead of the stupid 3/8" they supply with the pot. I also had about 20 1" tall legs welded to the underside of the false bottom to increase my liquid level and reduce the risk of boiling or scorching. My electric brewery is not complete yet so I am heating the mash tun on a banjo burner and am recirculating with a march nano brewery pump.
I recently made some breakfast bourbon (52% flaked maize and 48% rolled oats) I added 3 pounds of rice hulls per 100 pounds of grain, if I recall correctly I think I used about 110 pounds of grain in this recipie. I am converting my grain bill with Specialty Enzymes high temp and low temp enzymes.
I heat my strike water to about 205 f, stir in my grains and then add the Sebbrew HT. At this point if I wasn't to pokey I should be at 190f. I will let it sit till it drops to about 185f give it a stir with a long paddle to loosen up the bottom then turn on the pump and slowly open the valve until I get the flow I want. Once I have a good flow I will start the burner on very low (it really doesn't need much). Nothing is automated at this time so I really need to keep an eye on it. The enzymes work pretty fast and do a great job of chewing up the starches making it even easier to pump as time passes. Approximately every half hour my flow will start to slow down and I have to mix up the bottom with the paddle to restore full flow. When I am done with the high temp I throw an immersion chiller in until I reach 146f and then add the Seb Malt Super. Again I let it do its work and then with the chiller I crash down to pitching temp
I do ferment on the grain so when I am done I pump the wort into my fermenter and then scoop and dump the grain in.
A note about this. The rice hulls help a lot but the enzymes are really key to loosening everything up. Also when I first modified The false bottom (raising it) it crated a small gap around the perimeter which caused all sorts of problems. I fixed this with Jimbo's help (thanks) by attaching stainless mesh around the perimeter. It is now as tight at a ducks butt and no grain can pass through
Hope this helps
Windy City

I was curious about fermenting without filtering out the mashed corn first. Does it become less viscous and easier to separate after it’s fermented a bit?

[Dancing4dan]

I am using a modified 55 gal Blichman pot. I modified it by installing a 3/4" pick up instead of the stupid 3/8" they supply with the pot. I also had about 20 1" tall legs welded to the underside of the false bottom to increase my liquid level and reduce the risk of boiling or scorching. My electric brewery is not complete yet so I am heating the mash tun on a banjo burner and am recirculating with a march nano brewery pump.
I recently made some breakfast bourbon (52% flaked maize and 48% rolled oats) I added 3 pounds of rice hulls per 100 pounds of grain, if I recall correctly I think I used about 110 pounds of grain in this recipie. I am converting my grain bill with Specialty Enzymes high temp and low temp enzymes.
I heat my strike water to about 205 f, stir in my grains and then add the Sebbrew HT. At this point if I wasn't to pokey I should be at 190f. I will let it sit till it drops to about 185f give it a stir with a long paddle to loosen up the bottom then turn on the pump and slowly open the valve until I get the flow I want. Once I have a good flow I will start the burner on very low (it really doesn't need much). Nothing is automated at this time so I really need to keep an eye on it. The enzymes work pretty fast and do a great job of chewing up the starches making it even easier to pump as time passes. Approximately every half hour my flow will start to slow down and I have to mix up the bottom with the paddle to restore full flow. When I am done with the high temp I throw an immersion chiller in until I reach 146f and then add the Seb Malt Super. Again I let it do its work and then with the chiller I crash down to pitching temp
I do ferment on the grain so when I am done I pump the wort into my fermenter and then scoop and dump the grain in.
A note about this. The rice hulls help a lot but the enzymes are really key to loosening everything up. Also when I first modified The false bottom (raising it) it crated a small gap around the perimeter which caused all sorts of problems. I fixed this with Jimbo's help (thanks) by attaching stainless mesh around the perimeter. It is now as tight at a ducks butt and no grain can pass through
Hope this helps
Windy City

I was curious about fermenting without filtering out the mashed corn first. Does it become less viscous and easier to separate after it’s fermented a bit?

Yes…. But not all corn acts the same.

I ferment CORN MEAL on grain using YLY (Yellow label yeast). There is significant reduction in viscosity and less corn left. I either use a BIAB (Brew in a bag) or use a steam still for the stripping runs. Lately it has been steam.

In my experience Cracked corn will leave more corn behind. Flaked corn leaves less corn behind.

[Twisted Brick]

I was curious about fermenting without filtering out the mashed corn first. Does it become less viscous and easier to separate after it’s fermented a bit?

There are threads discussing the benefits of fermenting corn on-grain versus off-grain. Of importance to new folks is that newly-converted corn doesn't filter like gelatinized barley does through husks as with brewing. This generally leads distillers to default to fermenting on-grain. A light search should yield a generous amount of information.

To answer your question, yes. One of the positive results of squeezing after fermentation is that the newly-created ethanol effectively thins the new wash’s viscosity, making it easier to squeeze. The job of separating the fermented wash from spent grain doesn’t go away, but it becomes manageable.