Rubbermaid cooler volume

[Steve973]

I posted this question in somebody else's thread, but I don't know if it should have been asked there. I have the orange cooler with the white top made by Rubbermaid for mashing, with a Phil's false bottom inside. I think it's a five gallon cooler, but I can't remember for sure. I have made five gallon batches before with it. I don't think there's enough room for approximately thirteen lbs of grain along with 1.5 quarts of water per lb. that's 4.8 gallons of water alone. Then I'll need room for boiling water for mashout. I think I'm going to have to buy a seven or ten gallon cooler but then at least I'll be able to mash better. Any thoughts?

 

[uglygoat]

do it, you can use the five gallon cooler as a hot liquor tank for yer sparge...

 

[Steve973]

the other issue that concerns me is that I have the phil's false bottom that has the correct diameter for the 5 gallon cooler. It's definitely smaller than the 10 gallon cooler, so will that be an issue? it doesn't seem like it'd be a huge deal, but I'm really not sure. The igloo 10 gallon cooler is 15.8" in outside diameter, and my current cooler is 12.5" outside diameter.

 

[uglygoat]

yeah, that false bottom is not gonna do you a bit of good if it don't have a tight seal along the walls of the cooler. the sparge will follow the path of least resistence, and if you use a false bottom that is 3 inches smaller than what it should be, the water is gonna rush over the sides of the grain bed and bottom, instead of through... get another one, or build yourself a manifold out of copper or cpvc tubing and attach that to the outlet.

 

[Steve973]

Ok, to be sure that we understand each other properly... Have you seen the Phil's false bottom? It's a curved piece of pvc or plastic with holes drilled into it. This makes the edge sit squarely on the bottom especially when grains weigh it down. there's a pvc fitting in the middle of it at the highest point that connects via tubing to the output of the cooler. So it only lets wort that has passed through the false bottom exit the cooler. Do you still think it'd be a problem?

Pic of the false bottom:

http://www.homebrewers.com/product/5498

 

[uglygoat]

it was my understanding that you want a fairly tight seal between the edge of the false bottom and the walls of the cooler. if the false bottom is too small, it's gonna just sit on the bottom of the cooler and not leave any room for the grain to float, maybe getting the mash stuck..

i bet it will work though, the manifold i use lets the grain rest on the floor of the cooler.

 

[Steve973]

I am telling ProMash that I want to use 1.5 quarts per pound of grain, and so it tells me that I need 4.83 gallons for the mash. I picked up the ten gallon igloo cooler tonight, so that part isn't a problem. However, to mash out at 165, it says that I have to add over a gallon and a half of near-boiling water. Then it's telling me that i need the same amount (?) of sparge water. Then it says that the total volume of water will be 7.43 gallons, and that's way more than I want to have to boil down to around 5 gallons. I'm not sure what the mash schedule of ProMash is trying to tell me!

Can someone make some sense of it, please?

 

[Steve973]

I think I have this figured out now. Promash has some nice help screens to help obsessive people like me. Tell me if this sounds okay. I rounded up a little. i have almost thirteen lbs of grain, and i was shooting for approximately 1.5 quarts of water per pound of grain, so i rounded up to an even amount of five gallons for mash water, and that comes to 1.55 quarts per pound. Then I need to add 1.61 gallons of water for mashout. After mashout, "Water Needed" tells me that I need 1.25 gallons for sparging. This will give me 6.32 in the kettle, and five gallons to the fermenter after chilling. I might shoot for about a half-gallon more during sparge to make up for slight losses in the mash cooler.

Does this all sound reasonable, and will that be enough sparge water?