Author Topic: Mash Tun false bottom  (Read 1934 times)

Offline sundog14

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Mash Tun false bottom
« on: May 13, 2014, 07:15:35 AM »
I'm looking to make a false bottom out of perforated SS stock. Anyone know of material thickness and hole size?
Thanks,
Tom

Offline hopfenundmalz

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Re: Mash Tun false bottom
« Reply #1 on: May 13, 2014, 08:24:35 AM »
It is all in here. I saw a big sheet of the perforated SS where I worked in the storage rack by the machine shop, no idea what they were going to use it for. I mentioned this because you should be able to buy the material rather than punch all of those holes, unless you are a skilled metal worker. Or just buy a screen from one of the suppliers.

http://brewhardware.com/false-bottoms-filters/152-falsebottom
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Offline Thirsty_Monk

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Re: Mash Tun false bottom
« Reply #2 on: May 13, 2014, 05:18:09 PM »
Mc Master has perforated stock.


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Offline troybinso

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Re: Mash Tun false bottom
« Reply #3 on: May 13, 2014, 05:37:12 PM »
I used the following and it works well.

https://www.onlinemetals.com/merchant.cfm?pid=13521&step=4

Offline S. cerevisiae

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Re: Mash Tun false bottom
« Reply #4 on: May 13, 2014, 07:39:14 PM »
I used the following and it works well.

https://www.onlinemetals.com/merchant.cfm?pid=13521&step=4

That's the correct hole size (3/32") and on center spacing (5/32").
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Offline sundog14

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Re: Mash Tun false bottom
« Reply #5 on: May 14, 2014, 05:28:44 AM »
Thanks to all that replied. I'm a new brewer making mead and beer. I had an order placed for copper bar stock yesterday with onlinemetals and could have added the perforated metal. So .06" thickness works out to ~ 16 gauge which sounds correct. I had thought that the holes should be ~ 1/8" (.125") so this sounds good also. I've looked at websites, videos, etc. about various tuns (also called HLT or MLT?) and pretty much decided on the cylindrical water cooler type; probably 5 gallon as that's the size of the batches I'm brewing. My plan is to add a dip tube to the ball valve and mount the screen above the valve on stand-offs. That way there is a "smooth" bottom with no valves, pipes in the way when I stir. I may add a thermometer. What do you think?
Thanks again,
Tom 

Offline Jimmy K

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Re: Mash Tun false bottom
« Reply #6 on: May 14, 2014, 06:06:33 AM »
A 5 gallon mash tun will mash about 10lbs of grain, which is a 5% (1.050 OG) beer for a 5 gallon batch. Unless you only make session beers get a 10 gallon mash tun.
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Offline S. cerevisiae

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Re: Mash Tun false bottom
« Reply #7 on: May 15, 2014, 07:01:22 PM »
A 5-gallon mash tun will accommodate approximately 13lbs of malt with a liquor to grist ratio of 1.25 quarts per pound.   I can easily achieve 5.75 gallons of 1.062 wort using 11lbs of grist in my 5-gallon beverage cooler-based mash/lauter tun.    I could hit the mid to high-80s with 13lbs of grist and a final kettle liquid volume of 5 gallons with careful sparging.   
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Offline S. cerevisiae

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Re: Mash Tun false bottom
« Reply #8 on: May 15, 2014, 07:52:42 PM »
I've looked at websites, videos, etc. about various tuns (also called HLT or MLT?) and pretty much decided on the cylindrical water cooler type; probably 5 gallon as that's the size of the batches I'm brewing. My plan is to add a dip tube to the ball valve and mount the screen above the valve on stand-offs. That way there is a "smooth" bottom with no valves, pipes in the way when I stir. I may add a thermometer. What do you think?

Trust me, you do not want that much dead space in your mash tun. You'll risk bed compaction and a stuck sparge any time the liquid in the dead space falls below the bottom of the false bottom, which can happen if you attempt to drain the tun too quickly.  Additionally, dead space is wasted space in a cooler-based mash/lauter tun.

I have been using beverage cooler-based mash tuns with false bottoms since 1993.  Plumbing above the false bottom is the not a problem in practice because the mash should be floating.

Here's an internal shot of my current mash/lauter tun (my false bottom has 16% open space):



With that said, a false bottom is a waste of money if you are planning to use what Dave Miller refers to as "infusion rinsing" (a.k.a. batch sparging).  Batch sparging and continuous sparging (a.k.a. fly sparging) are  different animals with different crush requirements.  Denny's setup allows for a much finer crush than a traditional false bottom-based design.  Batch sparging requires a much finer crush than continuous sparging.


« Last Edit: May 16, 2014, 08:49:45 AM by S. cerevisiae »
Mark V.

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https://www.homebrewersassociation.org/forum/index.php?topic=19850.msg252492#msg252492

"A pale ale losing points for being too pale is like a vicar being defrocked for being too godly. It is no wonder that beer judges get such a bad rap."  - Graham Wheeler

Offline morticaixavier

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Re: Mash Tun false bottom
« Reply #9 on: May 15, 2014, 08:34:53 PM »
A 5-gallon mash tun will accommodate approximately 13lbs of malt with a liquor to grist ratio of 1.25 quarts per pound.   I can easily achieve 5.75 gallons of 1.062 wort using 11lbs of grist in my 5-gallon beverage cooler-based mash/lauter tun.    I could hit the mid to high-80s with 13lbs of grist and a final kettle liquid volume of 5 gallons with careful sparging.

sure you can, just barely though. and 1.25 is really thick, not ideal for conversion. why make life harder than it has to be? particularly when you are first getting into all grain. I've been happy with my 72 qt coleman for several years now. I can brew 12 gallons of moderate strength or a 5 and 5 partigyle strong beer small beer combo or brew a 5 gallon batch of whatever. batch spargeing allows me to not worry about stuck sparges and be done spargeing in ~25 minutes.

Over all, while a 5 gallon Mash tun might be enough I think the OP would be better off with a larger mash tun.
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Offline denny

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Re: Mash Tun false bottom
« Reply #10 on: May 16, 2014, 08:25:22 AM »
Batch sparging requires a much finer crush than continuous sparging.

No, it doesn't require it.  It allows it, but it's not a requirement.
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Offline S. cerevisiae

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Re: Mash Tun false bottom
« Reply #11 on: May 16, 2014, 08:53:50 AM »
Batch sparging requires a much finer crush than continuous sparging.

No, it doesn't require it.  It allows it, but it's not a requirement.

I guess that I should have qualified that statement. A finer crush is needed to achieve a comparable extraction rate.
Mark V.

Just say "no" to yeast rinsing
https://www.homebrewersassociation.org/forum/index.php?topic=19850.msg252492#msg252492

"A pale ale losing points for being too pale is like a vicar being defrocked for being too godly. It is no wonder that beer judges get such a bad rap."  - Graham Wheeler

Offline denny

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Re: Mash Tun false bottom
« Reply #12 on: May 16, 2014, 09:01:51 AM »
I guess that I should have qualified that statement. A finer crush is needed to achieve a comparable extraction rate.

Not in my experience.
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Offline S. cerevisiae

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Re: Mash Tun false bottom
« Reply #13 on: May 16, 2014, 09:56:35 AM »
What is the roller spacing on your mill?  What is your average extraction rate in points per pound per gallon (use final kettle liquid volume minus the break and hops for the calculation)? 
Mark V.

Just say "no" to yeast rinsing
https://www.homebrewersassociation.org/forum/index.php?topic=19850.msg252492#msg252492

"A pale ale losing points for being too pale is like a vicar being defrocked for being too godly. It is no wonder that beer judges get such a bad rap."  - Graham Wheeler

Offline denny

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Re: Mash Tun false bottom
« Reply #14 on: May 16, 2014, 10:58:00 AM »
What is the roller spacing on your mill?  What is your average extraction rate in points per pound per gallon (use final kettle liquid volume minus the break and hops for the calculation)?

I have no idea of the roller spacing.  I'm making grist, not gaps, so I set it to get a good crush.  I can't recall the last time I figured my ppg.  I'll do it when I brew next and let ya know.  Well, maybe not the next time, since I've got to brew 8 kits for Brewcraft next week.  But after that...:)
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