MIAB - mash tun size?

[vallonswayla]

I want to brew 3 gallon batches and want to use a 5 gallon cooler. I think the cooler is gonna be too small to do a full volume mash. Can I mash with 3.5 gallons of water plus grain and then add water at the end of the mash to reach the approx pre boil volume?

 

[doug293cz]

I want to brew 3 gallon batches and want to use a 5 gallon cooler. I think the cooler is gonna be too small to do a full volume mash. Can I mash with 3.5 gallons of water plus grain and then add water at the end of the mash to reach the approx pre boil volume?

Yes, but it would be more efficient to rinse the grain with the water prior to adding it to the boil. This is a common process known as "sparging." You don't need hot water for sparging - cold water works just fine (although heating to a boil will take a little longer.)

Brew on

 

[vallonswayla]

Could I scoop out some of the mash water from the tun(say 1/2 to 1 gal) and pour into the kettle, then add back in the equivalent amount of cold water into the tun and then drain everything into the kettle?

 

[madscientist451]

Sure, but if you just remove the drinking water spigot and replace it with a cheap gate valve spigot, you won't have to scoop the water.
I've used that method for years and ran full 5 gallon batches and batched sparged, but about a year ago I switched back to just BIAB in a pot, and wrapped insulation around it. I dunk sparge in a side pot and then combine everything.l
I run a lot of smaller batches so the BIAB in the pot works pretty good for me and there's less stuff to get out, clean and then put away again.
Its also faster, I pull out the bag, crank up the heat and don't have to wait for the mash tun to drain, plus the pot is already warm so the boil starts going faster.

 

[doug293cz]

Could I scoop out some of the mash water from the tun(say 1/2 to 1 gal) and pour into the kettle, then add back in the equivalent amount of cold water into the tun and then drain everything into the kettle?

You could do that, but you will get lower mash efficiency than if you just do a regular batch sparge.

Brew on

 

[lump42]

Could I scoop out some of the mash water from the tun(say 1/2 to 1 gal) and pour into the kettle, then add back in the equivalent amount of cold water into the tun and then drain everything into the kettle?

Yes, you could, but it would likely be easier to just drain the cooler and then add the remaining water to the mash and call it a sparge step.

You can use tools to help determine the volume of the mash.
https://www.rackers.org/calcs.shtml
https://manskirtbrewing.com/calculators.aspx#mashsizehdr

 

[lump42]

Sure, but if you just remove the drinking water spigot and replace it with a cheap gate valve spigot, you won't have to scoop the water.
I've used that method for years and ran full 5 gallon batches and batched sparged, but about a year ago I switched back to just BIAB in a pot, and wrapped insulation around it. I dunk sparge in a side pot and then combine everything.l
I run a lot of smaller batches so the BIAB in the pot works pretty good for me and there's less stuff to get out, clean and then put away again.
Its also faster, I pull out the bag, crank up the heat and don't have to wait for the mash tun to drain, plus the pot is already warm so the boil starts going faster.

I think the stock spigot would work if you have the thumb strength to hold it.

 

[wilserbrewer]

A five gallon cooler is plenty large enough and I wouldn’t consider going larger.

Mash with approx water to get 60% pre boil volume and then batch sparge with the amount your boil kettle is short...

This is very simple and eliminates trying to calculate your total water, instead you are simply measuring volumes rather than trying to predict them lol.