[DW]

Hey guys! This would be my first post.  Sadly I did not know about this forum, despite being a homebrewer for about 4 years.  I was wondering if a 10gallon rubbermaid mash tun would fit a 20.5lb grain bill.  Some have said "not doable", but others have said that if I use a water to grain ration of 1.25qt/lb, then it's doable.  If decreasing the water to grain ratio is the only way to make it work, then how would decreasing the ratio affect the beer?  Does a thicker mash decrease efficiency?  Anyway, my big question is can I go "all-grain" or do I need to decrease the grain and supplement with DME or LME.  Thanks!

[hopfenundmalz]

You can do it.  1.25 qt/lb is a fairly common thickness, and I used it for years.  Your efficiency starts to suffer if you go thicker, like 1 qt/lb or so.

Use this for a calcualtion.  Scroll down to Can I Mash It.  It says you can
http://www.rackers.org/calcs.shtml

[dean]

I was just about to post about the Green Bay Rackers site.    I was guessing off the top of my head it would fit though, 1.25 ratio is only ~ 25 quarts or so plus the grain volume... it would be tight but do-able I think.

The lower you go on your mash ratio, the maltier your beer will be supposedly.  I haven't done it in a while so I can't remember if it is or isn't.  And yeh, you lose efficiency somewhat.

[bluesman]

Go for it. 1.25:1 water/grain ratio should do just fine. Thicker mashes aren't as efficient but 1.25:1 should still give you decent efficiency. The GB Rackers site is a great resource to determine your capability. You will be able to fit all of your grain and water in the 40qt cooler to mash at 1.25:1. It should take roughly a little over 32 qts of your cooler volume leaving you 8 qts to spare. 

[tomsawyer]

5lb of grain takes up about 0.75gal of space in my little tun, your 20.5lb would presumably take up about 3gal of volume.  add that to your 6.4gal of water and you have 9.4gal total.

[oscarvan]

My question is....... will the Rubbermaid tub hold the heat in well enough?

[maxieboy]

My question is....... will the Rubbermaid tub hold the heat in well enough?

 Rubbermaid round cooler...

[oscarvan]

Ah, cooler......different animule. Thanks.