Bottom Draining Tun Deadspace?

[antony]

Hey gang,

I built myself a bottom draining mash tun from a decommissioned black rubber coated keg & I've got a false bottom in place. My question is regarding mash volumes. Should I measure the space below the false bottom to the drain (maybe .5-.75g) and then add this volume to my usual mash water volume? Just worried about having too thick of a mash. I used to brew in a bag so this false bottom thing is new for me. On the plus side, the super insulated mash tun holds water temperatures for hours...two degree drop over 10 hours (it's layered with reflectix).

Any advice on the mash volume would be greatly appreciated!

 

[IslandLizard]

Yup, just add it to your strike water volume.

If you're batch sparging, you'll drain it each time, there will be no wort left behind. That way there's no impact on your mash/lauter efficiency.

You're not recirculating?

 

[antony]

I recirculate the first few quarts or so. Should I be recirculating more? I generally pull off a gallon at most & pour that back. then i drain & batch sparge.

 

[IslandLizard]

I meant: do you continuously recirculate...

Any water/wort in the deadspace under the false bottom doesn't interact with the grain. So it can't have much gravity apart from what diffuses from above.

If there's only 2 qts in the bottom deadspace, it's all fine, IMO. If it's closer to a gallon, you may want to recirculate that gallon a few times during the mash. Drain a gallon and pour back on top. The only problem with that is you lose heat during that process.

Or just let it be for the whole mash duration, as is. When lautering, drain the gallon of the weak under-bottom wort and reuse as part of your first sparge volume. Lauter the rest as your first runnings. Repeat for the 2nd sparge. I think that would keep your efficiency as high as possible all other things being the same.

Maybe some others have better ideas.