Dead space with batch sprage with SS braid

[mcberry]

I tried searching for my answer, but to no avail.

It seems to me that the general method for dead space calculation (fill up, then drain, and count what's left) is only suited to using a false bottom - where there is truly dead space (i.e. nothing but liquid). For those that batch sparge with a converted cooler w/ SS braid, how is this technique relevant? That area below the spigot is filled with grain (and the water absorbed by the grain). Moreover, some liquid will be drawn uphill by siphon action (at least to the extent that the grain bed is airtight around the braid).

I'm sure there is some lost wort, but it seems to be an incredibly small amount. I plan to do an experiment to actually calculate this space by doing two different batches with 2 different grain weights, same water/grain ratio. Assuming constant absorption in each scenario, and accurately measuring runoff, a simple system of equations can be setup to get the true deadspace.

I've not done this, in fact I just add in 12 ounces for deadspace for no real reason, and always seem to hit my volumes (though I don't have ounce precision in my volume measurements).

Anyway, this is probably longwinded and unclear, so feel free to ignore if I rambled too much

 

[maida7]

I just add in 12 ounces for deadspace for no real reason, and always seem to hit my volumes (though I don't have ounce precision in my volume measurements).

sounds like you've already got it figured out. RDWHAHB

PS: You may be able to reduce that dead space by tipping the cooler towards the drain.

 

[Countryham]

i helped by buddy build his copper manifold in a square cooler, identical to mine. His had so much more left behind than mine did, and we finally figured out what it was. he didn't teflon tape his threads into the bulkhead fitting, and wasn't getting a good air tight seal. once the wort drained below the fitting, he lost any kind of siphon and couldn't pull any more. IMO, i'd say the dead space would start once the wort got below the top of the braid and allowed any air in. That is of course if your bulkhead is above the bottom of your cooler and not recessed down like some coolers do. If it slopes down towards the bulkhead, i'd say you'd be great and not have much left behind at all.