Help understanding mash tun deadspace vs deadspace loss

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Gresco

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Hi everyone,

I'm trying to set up an equipment profile in BeerSmith, and I'm struggling with some terms. A quick history: had my first all-grain brew day about a month ago, and I have an igloo cooler style mash tun, with false bottom (about 3.5-4 inches high) and the ball valve/drain sits well below it. I did not account for this loss of strike water, and had to rush to boil more (as I didn't boil enough). I was able to get it in and solve the issue. But now, I'm trying to make sure my calculations are all on track.

During the equipment profile set up in BeerSmith, I see

"Mash Tun addition to compensate for recoverable volume under the filter screen"

and

"Deadspace in mash tun (volume before filter you can't recover)?

I think I understand this, but just want to make sure..... I calculated .75 g between the drain and the bottom of the tun that I can't recover.
So is the addition of water, to compensate, going to be the space between the drain and the false bottom? or the bottom of the tun to the false bottom?

Kinda feel like I'm obsessing over a small detail, but because it's such a large space, I need to know that I have the right amount of water.

Thanks
 
I recommend you post that question on the BeerSmith Forum. Those guys over there are BeerSmith experts.
 
"Mash Tun addition to compensate for recoverable volume under the filter screen"

I don't know the answer, but that parameter name makes no sense at all. When a volume is recoverable, there's nothing to compensate for.
 
I realize now that my original question was a round-about way of asking the following. I'm going to back-up my process here. As I still don't understand the amount of strike water I need, I'm going to give up on the software until I can understand it better.

I have 7 lbs 4 oz of grains. I've calculated my strike water as 2.25 gal. This doesn't account for the space below the false bottom (a whopping 1.5 gal). I plan to batch sparge. Should I just add an extra 1.5g to my strike water? I just wonder how much this will dilute my wort as well. When I sparge the second time, I plan to just sparge with how ever much more I need in the kettle.
 
Here's the total water you'll need in the strike plus sparge:

- Desired Pre-Boil Wort Volume
- Grain Wort Absorption (about 0.12 gallons per pound)
- Mash Tun Dead Space (non recoverable)
- Hose/Pump Transfer Losses (mash tun to boil kettle)

How you split that between strike and sparge is largely up to you, but yes, generally you'll want to include the deadspace portion of the water in the strike if it's large, to avoid a too-thick mash bed.
 
Here's the total water you'll need in the strike plus sparge:

- Desired Pre-Boil Wort Volume
- Grain Wort Absorption (about 0.12 gallons per pound)
- Mash Tun Dead Space (non recoverable)
- Hose/Pump Transfer Losses (mash tun to boil kettle)

How you split that between strike and sparge is largely up to you, but yes, generally you'll want to include the deadspace portion of the water in the strike if it's large, to avoid a too-thick mash bed.

This is very helpful, thanks! Have a total of 8.1 gals, so I'll split it 4 & 4. Was mainly worried about the large space below the false bottom and not ending up with enough water on mash-in. But this should work.
 
I always use 5+ gal for mash and ~ 3 for sparge to try to even out the runnings after losses and absorption.
 
I don't know the answer, but that parameter name makes no sense at all. When a volume is recoverable, there's nothing to compensate for.

To a limit. If your false bottom is dry until you hit 4 gallons in the tun, you can't run a batch that calls for 4 gallons of strike water or all your grain will sit dry for the entire mash. I haven't observed how beersmith solves for that though. As a general rule, I'd say you don't want to run a mash where the "above false bottom" ratio is less than 1qt per pound of grain. That is, you calc out 1qt / lb and then add the water volume that would sit under the FB. In extreme cases, you'd end up with no sparge water, AKA a full volume mash.
 
Here's the total water you'll need in the strike plus sparge:

- Desired Pre-Boil Wort Volume
- Grain Wort Absorption (about 0.12 gallons per pound)
- Mash Tun Dead Space (non recoverable)
- Hose/Pump Transfer Losses (mash tun to boil kettle)

How you split that between strike and sparge is largely up to you, but yes, generally you'll want to include the deadspace portion of the water in the strike if it's large, to avoid a too-thick mash bed.

Finished my brew day yesterday, this formula worked like a charm. Yielded the exact amount that I was expecting. Also, as a plus, nailed my OG as well. Thanks again.
 
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