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General Category => General Homebrew Discussion => Topic started by: goscarletgry on March 15, 2010, 03:25:36 AM

Title: My Mash Tun problem
Post by: goscarletgry on March 15, 2010, 03:25:36 AM
I have been brewing for over a year now and have decided to upgrade my all grain system. I went from having a 5 gallon cooler mash tun to now a 48qt 12 gal mash tun. I have made two batches on this mash tun and keep running into the same problem. When doing a 5gal batch in this 12 gal tun I leave 1-2 gal of wort in the tun. Is this tun too big for a 5 gal batch? Also I did not make a new manifold for this one yet. I just used the octagon manifold from my old round 5gal tun which only occupies half of the bottom of the tun. Would making a square manifold the occupies the entire bottom solve this?

Thanks

Mike K.

Dayton D.R.A.F.T. Home Brew Club
Title: Re: My Mash Tun problem
Post by: tygo on March 15, 2010, 04:48:24 AM
A 48qt cooler is not too big for a 5 gallon batch.  I'm using a 70 qt cooler for my 5 gallon batches.  No matter what you're going to lose some volume.  The standard "absorption" number is 0.12 gallons per lb.  With my system it's usually more like 0.15 gallons per lb.  Either way, for say a batch with 12 lbs or so of grain you're going to lose the 1-2 gallons that you mention.
Title: Re: My Mash Tun problem
Post by: MrNate on March 15, 2010, 04:48:45 AM
Not too big in my opinion. Copper manifold with slits on the bottom?
Title: Re: My Mash Tun problem
Post by: euge on March 15, 2010, 04:41:21 PM
It might be worthwhile to investigate John Palmer's work on this. He's done the leg-work.

My suspicions are that a new manifold is needed.
Title: Re: My Mash Tun problem
Post by: BrewArk on March 15, 2010, 04:55:07 PM
... I just used the octagon manifold from my old round 5gal tun which only occupies half of the bottom of the tun. Would making a square manifold the occupies the entire bottom solve this?

If you are fly sparging, I would definitely recommend a new manifold.  If you are batch sparging it's a little less important, but if you are having recovery problems, it's probably worth the $ to have a manifold that matches your system.  If your manifold is costing you wort w/every batch, it'll pay for itself quickly enough.
Title: Re: My Mash Tun problem
Post by: ndcube on March 15, 2010, 07:09:32 PM
How high off of the bottom of cooler is the outlet for the manifold?
Title: Re: My Mash Tun problem
Post by: MrNate on March 15, 2010, 07:10:53 PM
ndcube is on the right track. We need pictures.

Think about it, guys... 1-2 gallons? Why would ANY manifold in ANY cooler leave that much wort behind? Something's rotten in the state of Denmark.
Title: Re: My Mash Tun problem
Post by: ndcube on March 15, 2010, 07:17:46 PM
Just too add... If it's the same height in both coolers then the cooler with more surface area on the bottom is going to leave more behind.  (Unless you maintain a siphon)
Title: Re: My Mash Tun problem
Post by: MrNate on March 15, 2010, 08:15:44 PM
If it's a copper or cpvc manifold, which I'm guessing it is from the "octagonal" description, chances are he's siphoning. Unless he has it upside down. Which was my initial guess (cpvc, big tubes, upside down) but since he's dun gone I guess we don't get the satisfaction.
Title: Re: My Mash Tun problem
Post by: Beertracker on March 16, 2010, 03:13:17 AM
Q: Is this tun too big for a 5 gal batch?
A: No

Q: Would making a square manifold the occupies the entire bottom solve this?
A: Yes

Here's a design that I'm using on a similar sized mash-tun. I'm averaging 78% efficiency and leaving less than a quart of wort behind. *All CPVC construction w/ slotted bottom.  8)

(http://farm5.static.flickr.com/4002/4436532593_8acee084f2.jpg)  

Title: Re: My Mash Tun problem
Post by: goscarletgry on March 16, 2010, 03:33:11 AM
Sorry to the late reply to all your questions. The new tun is square 13"x13", my old 5 gal octagon manifold is only 8" in diameter made of cpvc. I bought some copper today and going to build a square manifold for the new tun. The old manifold was a great design and was very efficient.

Title: Re: My Mash Tun problem
Post by: MrNate on March 16, 2010, 01:39:01 PM
Am I crazy here? Why on earth would he need to build a new manifold in order to solve the stated problem? Why would a circular manifold cause the stated problem? How does making a square manifold solve the stated problem?

No? Just me?

Allright, I guess that's why I stuck to BrewHaHa.
Title: Re: My Mash Tun problem
Post by: denny on March 16, 2010, 03:52:03 PM

No? Just me?

Allright, I guess that's why I stuck to BrewHaHa.

Nope, not just you.  The problem seems to me to be a case of just not getting a siphon from the manifold.  The solution seems to be getting the manifold to sit lower in the tun.  That could involve a whole new manifold design, but it's doesn't necessarily seem like it has to.
Title: Re: My Mash Tun problem
Post by: ndcube on March 16, 2010, 04:41:56 PM

No? Just me?

Allright, I guess that's why I stuck to BrewHaHa.

Nope, not just you.  The problem seems to me to be a case of just not getting a siphon from the manifold.  The solution seems to be getting the manifold to sit lower in the tun.  That could involve a whole new manifold design, but it's doesn't necessarily seem like it has to.

I have the same thought.
Title: Re: My Mash Tun problem
Post by: MrNate on March 16, 2010, 04:49:25 PM
I guess the point being that it'd really suck to build a brand new manifold that ends up having the exact same problem because the real problem with the original manifold was never addressed.
Title: Re: My Mash Tun problem
Post by: bluesman on March 16, 2010, 05:10:42 PM
I guess the point being that it'd really suck to build a brand new manifold that ends up having the exact same problem because the real problem with the original manifold was never addressed.

+1

I would diagnose the problem first then resolve it.
Title: Re: My Mash Tun problem
Post by: Beertracker on March 16, 2010, 05:39:47 PM
+2 Agreed! It just sounded like a design problem to me, but a new manifold probably won't do any good if the valve position is too high. My initial thought were just that which is why I included a pic of my design. It helps to alleviate this problem especially when combined with a pump. Just my 2-cents!  ;) 
Title: Re: My Mash Tun problem
Post by: goscarletgry on March 17, 2010, 03:45:32 AM
You guys are correct ! the valve is a good 2 inches above the bottom of the cooler, and my old 5 gal tun the valve is less than an inch from the bottom. Talked to a manager and he let me exchange the square 12gal cooler for a 10 gal round cooler. I measured the 10 gal cooler at the store and the hole sits less than an inch from the bottom.

Went home and installed bulkhead, valve, and my old manifold. I'm brewing Great Lakes Edmund Fitzgearld clone this Sunday.

Thanks for the help

Mike K

Title: Re: My Mash Tun problem
Post by: MrNate on March 17, 2010, 05:02:26 AM
Well, I'm glad it worked out for you anyway.
Title: Re: My Mash Tun problem
Post by: ndcube on March 17, 2010, 03:17:22 PM
I'm brewing Great Lakes Edmund Fitzgearld clone this Sunday.

That's a darn good brew.  What is the recipe your using?
Title: Re: My Mash Tun problem
Post by: goscarletgry on March 17, 2010, 07:05:54 PM
Edmund Fitzgerald Clone

5 Gallon Batch

11 lbs 2 Row Pale Malt
.5 lb Crystal Malt 60 Lovibond
.5 lb Chocolate Malt
.5 lb Special B Malt
.25 lb Black Malt

1.5oz Centennial Hops 60min
.5oz Williamette 15min
.5oz Williamette 5min

White Labs Yeast WLP007 Dry English Ale

60 Minute mash at 153 and batch sparge
O.G. .066 F.G. 0.18
Title: Re: My Mash Tun problem
Post by: yugamrap on March 18, 2010, 01:13:08 AM

No? Just me?

Allright, I guess that's why I stuck to BrewHaHa.

Nope, not just you.  The problem seems to me to be a case of just not getting a siphon from the manifold.  The solution seems to be getting the manifold to sit lower in the tun.  That could involve a whole new manifold design, but it's doesn't necessarily seem like it has to.
+1