$5.00 False Bottom Plan

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zzARzz

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Hey Everyone,

I wanted to do my first all-grain brew and did a lot (A LOT) of research into to the best methods, costs involved, etc. I decided that the false bottom would give me the most flexibility, but at anywhere from $30-$100 for professionally made ones, my inner Scrooge said, "Bah, humbug!" So I did some more looking and came up with my own using only $5 worth of parts. It's for a 5 gallon Igloo beverage cooler, but the design is simple and could be modified for almost any size round mash tun. I'll admit I'm as green as one gets to brewing and would greatly appreciate any comments and suggestions about my design. It's still untested, but I'll be brewing a Scottish Heavy Ale next week and will post an update as to how it performed.

Parts List
(1) 9" 18-gauge Aluminum Pizza Pan; 0.4" depth - {I got mine from a restaurant supply store} - $2.88
(1) PEX Elbow Adapter; brass - {From Home Depot in the plumbing section} - $1.71
(2) #31 O-Rings - {Home Depot in the faucet repair section} - $0.23/ea
1/8" drill bit
1/2" or 3/8" drill bit - {Depending on your inlet size; I made my assembly out of 1/2" parts, so I used a 1/2" bit}
Variable speed drill
Ruler or T-Square
Pencil
Scotch Tape
Old cutting board or sheet of wood
Safety Glasses - {Better to look like a dork for an hour that a pirate the rest of your life :D}

How To
Begin by taping the pizza pan domed side up to the cutting board. This will make it easier for the rest of the steps. Use the ruler or T-Square to draw a straight line down the center of the pan. Rotate it 90 degrees and make another line so the cross marks the center of the pan. Mark the lines every 1/2" from the center out to the edges on each axis. Finally draw parallel lines at each mark to form a grid:
grid-sm-55562.jpg

Put on your goggles and start drilling 1/8" holes at each point on the grid. There'll be about 250 of them so it'll take a while.
drilled-sm-55559.jpg

When that's done, use the 1/2" or 3/8" bit to drill the port in the center of the pan for the PEX elbow. Use a wire brush, sandpaper or the like to clean all the barbs off the underside of the pan from drilling. Wash the pencil grid of the pan and use a garden hose or high pressure water to clean off any metal flakes that may have collected in the rolled rim of the pan.

Take one of the O-Rings and push it onto the inlet side of the PEX elbow about halfway down the barb. Insert the elbow into the port in the center of the pan so it looks like this:
elbow-top-sm-55561.jpg

Holding it in place, take the other O-Ring and push it over the inlet barb on the underside of the pan. The PEX elbow should be held firmly in place, decently sealed and easily rotated:
elbow-bottom-sm-55560.jpg

Here's mine installed in my mash tun. I used 3" of 1/2" braided tubing to hold mine in place and it is held snugly. You could also use copper tubing with compression fittings, but I find this way much easier to deal with as far as installation and cleaning are concerned.
installed-sm-55563.jpg

I put 1 gallon of water into the tun to test dead space and it was only 1/4 gallon short, so not too bad. Hopefully some of you can mess around with the design and I'll post my findings when I brew next week.

NOTE
11/16/2012 -- A few people have mentioned that due to the lightness of aluminum there have some issues with the false bottoms floating while mashing, causing stuck sparges by grist getting caught in the dip-tubes and lines. One way to remedy this is to use rigid, braided food-safe tubing from the PEX elbow to the barb on the valve. This is what I use and I haven't had an issue with floating or stuck sparges.

Another would be to use compression fittings and copper/SS tubing which would keep the false bottom in place as well. This is what I'll likely use when I upgrade to a 10 gallon mash tun in the future.

Finally, adding weights to the false bottom such as SS washers above and below the PEX elbow or weights mounted along the upper edge of the rim would likely cure this issue as well.

Update

I brewed with this false bottom for the first time today and I’m honestly impressed at how well it worked! Hit 85% efficiency and had only a pinch of grain material come out while fly sparging. The tun had a fast, steady flow and didn’t even hint at a slow or stuck sparge. Had exactly 5.7 gallons of wort which was what BeerSmith predicted.

Even though this is my first all-grain brew, this false bottom worked much better than my friend’s who uses the braided S/S line method. She often has to fiddle with it and complains of stuck sparges all the time. Cheap B-Day present, perhaps? :D

I got the hole size and spacing parameters from a fantastic article I read by John J. Palmer and Paul Prozinski here: http://morebeer.com/brewingtechniques/library/backissues/issue3.4/palmer.html. It has some great info on improving mash efficiency and it taught me quite a bit.

UPDATE
12/3/2012 - I upgraded to a 10 gallon Igloo cooler for my mash tun to do higher gravity brews and made a new false bottom. This one is made from a 12" stainless steel pizza pan I purchased from Amazon for $13. I cannibalized the parts from my 5 gallon mash tun and they work flawlessly. Here you can see the the false bottom made with the same 1/8" drilled holes at 1/2" offsets. I set the PEX pickup end as low as possible under the false bottom as this pan is a bit deeper than the 9" in the previous build. Hopefully this will minimize the wort lost to dead space. I'm planning an Imperial IPA next and will report the new mash tun's performance once it is complete.

ssfb1-57504.jpg


ssfb2-57505.jpg


ssfb3-57507.jpg


UPDATE

12/29/2012: Brewed an Imperial IPA with the new 10 gal mash tun and 12" pizza pan false bottom. Worked even better than the original 9" version. The addition of S/S hose clamps on the dip tube made grain material in the 8qt re-circulation almost non-existent so I highly recommend using them with this design. Hit 82% efficiency and there was no hint of a stuck sparge (very smooth, slow, steady flow). I'm very happy that a second iteration of this design has proven as effective as the original.
 
Going to resurrect this thread because I think it's a great idea. I love ghetto brewing.

Anyone have any thoughts on how hard it would be do this with a stainless pizza pan such as the one below? I think they would be thin enough to easily drill, but perhaps would go through a lot of drill bits?

http://www.amazon.com/Norpro-13-1-2-Inch-Pizza-Pan/dp/B000SSVP5S/ref=sr_1_11?ie=UTF8&qid=1344816213&sr=8-11&keywords=stainless+12+inch+pizza+pan

I'm also curious to see if we can find a perforated pizza pan with small holes. I'm seeing perforated pans, but the holes look huge. I'm going to start googling.

Update - a quick search turned up Air Bake pans, which appear to have small holes. These are aluminium and apparently only come in 15.75 inch diameter. Smaller 12.75 inch pans are available, but have a non-stick coating.

http://www.bedbathandbeyond.com/1/1/1000-air-bake-ultra-insulated-15-3-4-large-pizza-pan.html
 
Don't fear the Stainless steel. Just get a few REALLY GOOD bits and use a drill press. I drilled all 1,023 holes in this Sanke Keg cut-off False Bottom with only 2 drills. Use GOOOOD cutting oil too!
attachment.php
 
I just finished my pizza pan false bottom and It looks great. I drilled probably 3 or 4 time more holes but I'm going to use it in my keggle and used a 2.5mm drill bit (about a 1/10 bit)
 
Congratulations on finding the first legitimate use for a perforated pizza pan!

(Yes, I'm one of those snobs with a professional grade slab in the bottom of their oven - the perforated pans do their job poorly and are a PITA to clean cheese out of)

(if you want a solution that works and is easy to clean, go to a restaurant supply and ask for a pizza screen. for pizza, i mean.)
 
How long does it take to preheat the slab of stone in your oven? I bet it cooks pizza REAL well! How hot do you cook it?

I use a Fibrament(tm) stone, and i like to preheat it for 90 minutes, as hot as the oven will go, but i don't have a self-cleaning oven. People with self-cleaning ovens can hack the oven to let them bake with the self-clean cycle.

My ir thermometer says that i've had the slab as high as 630f. For reference, the neapolitan pizza fascists demand something like 710f. Of course they express it in celsius.

Anyway, fully heated, a 12" hand-tossed thin crust with a reasonable amount of cheese and toppings has a bake time in the neighborhood of 2 minutes.

And there is nothing quite like the smell of pizza crust searing against a hot stone.
 
1023 holes!
Did you do the beer song when drilling? 1023 holes to go 1023 holes...... ya drill the hole ya drink a home brew 1022 holes to go 1022 holes....
 
But really, this is a great idea, and if I'd seen this thread before i bought my morebeer SS false bottom, I might have done it myself.
 
Yep... 1,023 Holes. I counted them! Oh. And 66 slots with an angle grinder! But. That work got me 93.7% efficiency on my first batch with it!
 
Don't fear the Stainless steel...I drilled all 1,023 holes in this Sanke Keg cut-off False Bottom with only 2 drills.

Wow...for the price of two "drills" one could purchase an actual false bottom. ;)
 
zzARzz,
Nice job on the pizza pan. I really liked that magazine (BT). I was one of their inaugural subscribers back in the 90s. I stopped brewing for a few years (15?) and that magazine didn't make it.
 
Wow...for the price of two "drills" one could purchase an actual false bottom. ;)

Drills are cheap... even good drills. These cost me nothing. My Dad and his Dad were in the aerospace industry as tool makers for quite a while. These were some of Grand dad's leftover HIGH-END drills.

Are you thinking Drill Motors? The actual cutting tool is called the drill... the motor you hold in your hand is mistakenly called a drill by a LOT of people. Besides, I did these all on a drill press with a sacrificial piece of wood behind it to help keep burrs to a minimum.
 
Drills are cheap... even good drills. These cost me nothing. My Dad and his Dad were in the aerospace industry as tool makers for quite a while. These were some of Grand dad's leftover HIGH-END drills.

Are you thinking Drill Motors? The actual cutting tool is called the drill... the motor you hold in your hand is mistakenly called a drill by a LOT of people. Besides, I did these all on a drill press with a sacrificial piece of wood behind it to help keep burrs to a minimum.

What does that make the motor inside the drill motor? The drill motor motor? Only teasing...:mug:
 
Husco,

Actually I thought you made a typo and meant to say "drill bits". Sorry for that.
 
Hi Everyone,

Thanks for all the interest in my "ghetto" false bottom (that made me laugh). I've brewed with it 4 times since making this thread and it has performed flawlessly every time. I did a 45 minute sparge with it on my last brew (a honey wheat beer) and I didn't have a hint of a slow or stuck sparge.

Some of you mentioned using perforated pizza pans and pizza screens. I looked into those options first, but when I went to a restaurant supply store to pick up the pan I used here, I looked at them and found that the holes were a bit too big; I worried about them letting too much grain through to be useful. The only ones I found with 1/8" holes were of the flexible silicone variety which wouldn't work for obvious reasons.

A stainless steel pan is a great option too and I looked into that as well. Given that this was a bit experimental to begin with and I'd never done an all-grain brew up to that point, I decided to go with the cheap aluminum one, but when I decide to make another I will likely go the SS route since the design works so well in the one I have now. I will also probably try it with a copper dip tube using compression fittings, but I haven't had any issues with the 1/2" rubber hose, o-rings and PEX fittings in this one. Probably the nicest thing with it is how easy it has been to clean: just spray it with the garden hose, wash with soapy water, sanitize and away it goes.

I used a 1/8" cobalt bit and a hand drill to make the holes since aluminum is a forgiving material, but would likely use a hobby drill press on a stainless steel pan to avoid the bit "walking" as would likely happen.

Thanks again for all the interest in my subversion of the professional false bottom industry and I look forward to everyone's improvements!
 
I found a perforated pizza pan at a local kitchen store, they only had the teflon coated 15.75" ones. It is labeled "perforated cookware", but appears identical to the airbake pans I linked to earlier. The holes are 1/8". I would rather avoid the teflon, just personal preference, I don't see a need for it in this application.

I've been looking to set up my last keg as a mash tun with a false bottom. Thinking about going with the bottom drain setup with a tri-clover connection.

I just need to decide whether to try the aluminum Airbake perforated pizza pan, which won't require any drilling, or the stainless one, which will. So many decisions...
 
I found an alternative for square cooler users utilizing perforated hotel pan inserts from restaurant supply stores here: http://www.wasserstrom.com/restaurant-supplies-equipment/Product_115467

It would be easy enough to modify it with a dip tube and they come in various sizes (known as full, half, quarter, etc.). Most are made from aluminum, but for those wanting SS, they have these available that would make a good start for drilling your own holes: http://www.wasserstrom.com/restaurant-supplies-equipment/Product_100134

A bit more expensive than the pizza pan version, but still a lot cheaper than most pro-made ones.
 
Good find.
You may want to cut some short lengths of copper pipe to "chair" up the span of that rectangle pan if you use it as a FB. It is not self supporting like a domed structure would be. The weight of the grain may push it down in the center and hinder your flow. It would only take 5 short pieces arranged like dots on the 5 side of a dice.
 
Good find.
You may want to cut some short lengths of copper pipe to "chair" up the span of that rectangle pan if you use it as a FB. It is not self supporting like a domed structure would be. The weight of the grain may push it down in the center and hinder your flow. It would only take 5 short pieces arranged like dots on the 5 side of a dice.

Great suggestion. You could also use some plastic plumbing spacers and small S/S or brass plastic screws in the same formation to support the bottom. If using the thinner aluminum pizza pans for a large mash tun (12"+ diameter), it would probably be a good idea to add these supports t it as well. Maybe 4 in a square around the inlet?
 
I had a similar idea. I found this microwave screen at an ACE Hardware for $3 and it worked great!

Nice find! I love it when people can see odd stuff like a microwave splatter screen and say, "I bet I could make great beer with this!"
 
Struck out on the splatter screen at ACE. Went to two stores and searched online.

Found the manufacturer's (Chef Craft) website link to the white splatter screen here: http://chefcraft.com/store/kitchen-gadgets/kitchen-helpers/microwave-splatter-screen-wht.html

It says you have to log in to view pricing, so I'm not sure you can order it directly or as a single unit, but they're also for sale on eBay here: http://www.ebay.com/itm/NEW-MICROWAVE-SPLATTER-SCREEN-SPLATTER-GUARD-Chef-Craft-9-Kitchen-Tool-Tools-/280859710761
 
"I used 3" of 1/2" braided tubing to hold mine in place and it is held snugly. "

Where did you get the tubing from? Home depot?
 
"I used 3" of 1/2" braided tubing to hold mine in place and it is held snugly. "

Where did you get the tubing from? Home depot?

Yes. In the brass fittings/plumbing section where you would get parts for bulkhead assemblies (like barb fittings, PEX elbows and pipe nipples).
 
Home Goods had a 12 inch aluminum pizza pan. Hopefully its deep enough, there was no depth. I think its at least 0.4 inches. It was only 5 bucks. Started drilling. It isn't as pretty as pics on page one since i was eyeballing my lines with a little ruler help.
 
I have silicone tubing i use to transfer wort from MLT to ketle. COuld I use some of that or will it just crush under the pressure of the grains? Its obviously not braided.
 
I have silicone tubing i use to transfer wort from MLT to ketle. COuld I use some of that or will it just crush under the pressure of the grains? Its obviously not braided.

I think the idea is to cut it lengthwise and slip it over the edge of the FB.


Nevermind... I was thinking about a different FB thread. Sorry.
 
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