Using a cooler bigger than you need for a mash

[linusstick]

Dumb question I know. I have a little 5 gallon cooler that is maybe 10 years old already converted to a mash tun (bought it that way). View attachment ImageUploadedByHome Brew1503426346.899953.jpg
It has this type of spigot. Used it for the first time in a long time today and it leaked a little and didn't drain well. I also have a 10 gallon mash tun with a false bottom and better spigot but I'm only doing 1.5 gallon batches of beer. View attachment ImageUploadedByHome Brew1503426524.831697.jpg would I be better off using the bigger tun with the false bottom or should I dial in the smaller one? I was disappointed in only getting a 61% mash eff compared to mid 70s when I was doing BIAB and I'm trying to decide if I just keep doing what works or branch off into more traditional batch sparging. I like doing both so I'm just thinking out loud

 

[JayInAmes]

I would think part of the decision would be how much deadspace is there? Might not be worth a 1.5 gallon batch in the big one if the waste is .75 gals or more.

 

[Gonefishing]

I'm curious why dead space is a concern in a mash tun. I could see where grain bed depth might be a concern, but dead space?

 

[philjohnwilliams]

I'm curious why dead space is a concern in a mash tun. I could see where grain bed depth might be a concern, but dead space?

Because after you drain the tun, the wort in the deadspace contains sugars that are not going into your kettle.

 

[Turkeyshot]

Because after you drain the tun, the wort in the deadspace contains sugars that are not going into your kettle.

Makes sense, but in a small enough mash tun, just tilt it to get out every drop.

 

[Gonefishing]

Because after you drain the tun, the wort in the deadspace contains sugars that are not going into your kettle.

OK, now I understand. I was thinking the dead space was the space above the mash, without considering the space below the drain.