Size of mash tun for 15 gallon batches

[Waterlogged]

After 3 very successful BIAB batches of beer, we are now considering a mash tun.  We want to up our efficiencies and reduce the grain bill.  We are looking at several cooler options and have decided on a rectangular marine extreme type cooler.  So my questions are:

- Cooler capicity for 30 lb of grain.  We are considering the 100 qt range but could this be too large? Depth of grain bed to shallow?
- Braided SS filter (Bazooka filter) as apposed to a copper manifold with drain slits cut into it.

Any suggestions?

Reid

[Chris Craig]

I can mash over 20lbs of grain in a 48 qt Coleman at 1.25 qt/lb, so I think a 70 qt cooler would be perfect.  100qt, would be too big, I think.

[JohnQ]

There are plenty of good ones out there, I'll leave that to the other squrare users to comment on...

Just thought I'd comment on capacity.
You mention 30 lbs of grain for a 15 gallon batch.

I have been known to use 75 pounds of grain on a 20 gallon batch, (after strike water, fills the 30 gallon MT to the brim) so personally I'd be looking at more like a 60 pound capacity as a minimum.
Following that math, my 120 litre capacity MT holds 75 lbs of grain so 60 lbs of grain should require about 100 litre capacity cooler...presuming you don't want to do a higher gravity beer than my AGDTDiePA, in which case you should consider 120 litre capacity since you could then do 15 gallons of probably a 1.100 beer.

Oversizing on the rectangular coolers might be an issue too, I don't know and will leave that for others to comment on as well.

[Waterlogged]

Well, there is currently a 70 qt cooler on sale at CNDtire so maybe that would be the ticket.

[Chris Craig]

You should aim to keep the Mash Tun at least half full, I think.

[Waterlogged]

Well, after browsing the canadiantire website I think the 70 qt cooler is the option for us.  The next size up is 100 qt which I think will be to large for our brews.

[JohnQ]

PM Richard and ask him what size he was looking for.
You're doing 15 gallon batches, and he was up sizing I remember and was looking for a bigger MT.
He's had lots of experience with that style I think, too.

JQ

[brew]

I use the coleman extreme 70 for 10G batches and it works well for me. I think I could do a 15G in it if I really filled it up... My big beers go a bit over half way up after adding 30-40L of strike water...

[Kyle]

I use a 70qt Coleman Xtreme cooler (quite a few 10gallon batches), and it is great for anything up to about 8.5%abv. After that space becomes an issue, but if you do a tight mash with 2 sparges, you can do Imperials using that cooler.

Edit: 70qt works for most 10 gal recipes: it is too small for 15 gallons. CDN Tire has a 150qt cooler on 50% off right now: that would give maximum versatility for 15gal batches, and be okay for most 20gal batches

[JohnQ]

Edit: 70qt works for most 10 gal recipes: it is too small for 15 gallons.

Kinda what I was thinking. You'd max out at what, about 6% at 15 gallons.

JQ

[Waterlogged]

So am I hearing the 150 quart cooler would be the best option for our 15 gallon 1.05 - 1.06 OG beers?  We are interested in Imperials and barlywines but are worried that on a normal lower OG beer, the grain bed may be too shallow for propery filtration.

[JohnQ]

I guess that's all about the geometry.
If the increased volume in the large one is achieved mostly through more depth, then it's not a problem...if it's achieved in the width and depth that might be an issue.

JQ

[brew]

I agree a 70 quart extreme would be too small for 15G batches regularly with good flexibility in ABV (although I think I could squeeze in a 7 or possibly 8% grain bill if I filled it to the top - I haven't tried a barley wine and probably won't ever). I think a 150 quart would be needed for 20G batches, but 100 quart would likely be perfect for 15G batches...

[Waterlogged]

I am starting to lean towards to 100 quart.  Seems to be the best fit.  just wish it was on sale but beeter to buy it at full prcie then to buy on on sale and need to purchase another one later that actually fits better.

Thanks for all the help.

[Waterlogged]

Well this beauty is available at Costco for $99.  It is almost a shame to turn it into a mash tun.

http://www.canadiantire.ca/AST/browse/5/SportsRec/Camping/Coolers/PRD~0853663P/Igloo+Wheeled+Marine+Cooler%2C+110+Quart+%28104+L%29.jsp?locale=en