Brewsmith - Mash Tun Deadspace / Whats left in the kettle

Hey Guys,

Quick question, I just bought a dip tube for my mash tun.

I have 1.25gallons of dead space, and previously was using that number as my mash tun deadspace and having beersmith calculating it. Worked ok but my efficiency was terrible (figure I was leaving way to much wort behind)

So I got a dip tube, bent it so its super close to the bottom of the tank...Yay!

Now I have to figure out how to calculate the mash water to reach my desired grist thickness.

So now i have:

Deadspace below scree: 1.25g

Whats left over after draining: 0.15g (2 1/4 cups)

So what should I punch into Brewsmith? .15? and then just manually add in the extra 1.1 gallons for the first mash?

Thanks!

There are (at least) two ways to handle this difference.

First, and the most straight forward, is to use the 1.25 gallons as the constant. BeerSmith will add the extra water to your desired grist ratio. Then, after doughing in, simply unclick the "Adjust for Mash Deadspace "button and the sparge water will change to account for the recovered MT wort.

The second way, and better for printed recipes, is to just design the recipe with your desired liquor to grist ratio, using 0.15 gallons as your deadspace number. Once all of the grains are finalized, just add the 1.1 gallons to the strike water in the mash steps. BeerSmith will again adjust the sparge volume to account for it and you won't have to fiddle with liquor to grist ratios during the recipe design.

brewfun said:

There are (at least) two ways to handle this difference.

First, and the most straight forward, is to use the 1.25 gallons as the constant. BeerSmith will add the extra water to your desired grist ratio. Then, after doughing in, simply unclick the "Adjust for Mash Deadspace "button and the sparge water will change to account for the recovered MT wort.

The second way, and better for printed recipes, is to just design the recipe with your desired liquor to grist ratio, using 0.15 gallons as your deadspace number. Once all of the grains are finalized, just add the 1.1 gallons to the strike water in the mash steps. BeerSmith will again adjust the sparge volume to account for it and you won't have to fiddle with liquor to grist ratios during the recipe design.

Click to expand...

Awesome thanks!

Another thing I have been doing is this:

I have .25 gallons of unrecoverable dead space, but a total of 2.75 gallons under my false bottom. A difference of 2.5 gallons.

I add this number(2.5g) to the "Brew Kettle Top Off" space in my equipment profile, which automatically deducts 2.5gallons from my Sparge Water every batch.

It should in theory keep all ratios the same on paper as well.

bbenesh said:

Another thing I have been doing is this:

I have .25 gallons of unrecoverable dead space, but a total of 2.75 gallons under my false bottom. A difference of 2.5 gallons.

I add this number(2.5g) to the "Brew Kettle Top Off" space in my equipment profile, which automatically deducts 2.5gallons from my Sparge Water every batch.

It should in theory keep all ratios the same on paper as well.

Click to expand...

I have a very similar issue, and I'm trying to figure out how to fix it. Doing as you've done and putting the difference between my false bottom and actual dead space as top off, how does that affect your mashing volumes?

You 'fix' it by entering the actual dead space volume (0.25 gal) into your equipment profile. Otherwise, your mash efficiency as calculated by BeerSmith will always be lower than your actual value.

Oginme said:

You 'fix' it by entering the actual dead space volume (0.25 gal) into your equipment profile. Otherwise, your mash efficiency as calculated by BeerSmith will always be lower than your actual value.

Click to expand...

I get that you don't want to count the whole volume under the False Bottom as dead space because you'll end up double counting the space between the false bottom and and the actual dead space. However, where I get confused is how to get the correct Strike Water and Sparge Water. If I don't account for the space between the dead space and the false bottom (about 2 gallons in my case) I will barely get the grains wet. If I do count it as dead space then I end up with 2 gallons too much in my boil kettle.

I know this shouldn't be rocket science but I typically end up brewing after my son goes to bed and by that point i'm not great at doing math on the fly, plus its really hard to juggle those things while trying to learn your efficiencies etc. for a new brewer.

I would look at your initial infusion versus your sparge volume. I have my mash profiles set up to produce approximately equal running from both, which means (for me) mashing in with about 3.7 liters/kg (1.8 gal/lb). This accounts for dead space and grain absorption. This also has the benefit of having a lower head space in my mash tun for higher gravity recipes and less temperature loss.

Edit: Ooops, 1.8 qts/lb.

Oginme said:

I would look at your initial infusion versus your sparge volume. I have my mash profiles set up to produce approximately equal running from both, which means (for me) mashing in with about 3.7 liters/kg (1.8 gal/lb). This accounts for dead space and grain absorption. This also has the benefit of having a lower head space in my mash tun for higher gravity recipes and less temperature loss.

Click to expand...

So for my next batch I have a grain bill of:
10 lbs Pale Malt (2 Row) US (2.0 SRM) Grain 76.92 %
2 lbs Vienna Malt (3.5 SRM) Grain 15.38 %
8.0 oz Cara-Pils/Dextrine (2.0 SRM) Grain 3.85 %
8.0 oz Caramel/Crystal Malt - 20L (20.0 SRM) Grain 3.85 %

So 13 lbs.

So you'd be mashing in 23.4 gallons of water?

I can't contain that volume, my Mash Tun is an 8 gallon pot w/ a false bottom.

If I do the calculations manually it looks kinda like this:
Kegging Volume: 5G
Fermenter Loss: 0.5G
Cooling Shrinkage (per BS): 0.23G (4%)
Post Boil volume: 5.73G
60 Min Boil Off: 1.63G (did a full 60 min boil of water and measured)
Pre-Boil Volume: 7.36G
Grain Absorption @ .125 G/# : 1.625 G
Total Mash/Sparge Water: ~9.0G

I don't have it in front of me but BS is giving me Strike water of like 13.somethign Quarts (3.something G) and like 6.something Gallons of Sparge water. Which I understand if you're using a cooler/SS Braid but my false bottom has like ~2 gallons under it and there's no way I can mash 13# of grain in what amounts to 1-1.5 gallons of water.

Do I just measure that 1-1.5 from above the false bottom and subtract it from the sparge water? If I do that do I need to recirc the first two gallons of run off from my mashing liquid to account for the lack of sparge water?

And is there a way to do this type of stuff in BeerSmith because inevitably get confused/2nd guess/blank while i'm actually doing it and **** it up and have to try and account for the extra water by boiling it off prior to my hops additions, which does correct volume but totally screws up any pre-boil gravity readings and makes it impossible to figure my efficiency.

Thoughts? Sorry if I missing something obvious here.

Sorry for that, it's 1.8 QTS/lb of grain. My bad.

I'd say that your system is undersized for the volume you are trying to make.

Oginme said:

Sorry for that, it's 1.8 QTS/lb of grain. My bad.

Click to expand...

Ok so you'd use (w/ my 13# grain bill) 23.4 Q (5.85 G) of strike water, of which you'd lose ~1.65 G so first runnings of ~4.2 G, then sparge w/ ~3.15G? ( calculated ~9G total water usage - 5.85 from strike water) is that correct?

Close enough. lose another 0.25 gal for deadspace out of the first runnings.

Accounting for about 1 gal of displacement by the 13 lbs of grain, I would revise my statement that you are undersized. I'll blame it on too little sleep last night and trying to do unit conversions in my head.

The way that I would figure it out is:

Pre-boil water needed = post boil water + boil off = 5.73 + 1.63 = 7.36 gal

Runnings from sparge = 7.36 / 2 = 3.68 gal = 1st runnings

Strike water = 1st runnings + dead space + loss to grain absorption = 3.68 + 0.25 + 1.63 = 5.56 gal

Water to grain ratio: 5.56 gal / 13 lbs = 0.43 gal/lb = 1.71 qts/lb

Capacity check: strike water + grain displacement = 5.46 + 1.01 gal = 6.47 gal < 8 gal -----> good to go.

Oginme said:

Close enough. lose another 0.25 gal for deadspace out of the first runnings.

Accounting for about 1 gal of displacement by the 13 lbs of grain, I would revise my statement that you are undersized. I'll blame it on too little sleep last night and trying to do unit conversions in my head.

The way that I would figure it out is:

Pre-boil water needed = post boil water + boil off = 5.73 + 1.63 = 7.36 gal

Runnings from sparge = 7.36 / 2 = 3.68 gal = 1st runnings

Strike water = 1st runnings + dead space + loss to grain absorption = 3.68 + 0.25 + 1.63 = 5.56 gal

Water to grain ratio: 5.56 gal / 13 lbs = 0.43 gal/lb = 1.71 qts/lb

Capacity check: strike water + grain displacement = 5.46 + 1.01 gal = 6.47 gal < 8 gal -----> good to go.

Click to expand...

Ok I think we're speaking the same language now (I'm playing single dad this week with a sick 12 month old so I'm in the same sleepless boat as you lol)

Just to be sure I'm on the right track here: total preboil water vol divided by 2 with 1/2 to sparge water/2nd runnings and 1/2 to first runnings.

First runnings + absorption + true dead space = Strike water.

So that all makes sense but I still come back to my original quandary: If i have ~2 gallons under my false bottom then essentially instead of a ratio of
5.56 gal / 13 lbs = 0.43 gal/lb = 1.71 qts/lb

its more like

3.56 gal / 13 lbs = 0.27 gal/lb = 1.08 qts/lb above the false bottom, which feels low.

Does this check out or does that water being below the false bottom not matter? If it does need to be adjusted for a) how do I do it (I'm assuming I'd steal 2 gallons from my sparge water to keep the ratio above the false bottom the same as the initial ratio?) b) do I need to recirc some of those 1st runnings to account for the lower sparge volume if I do c) is there a way to handle this in beer smith?

First, you are treating the water under the false bottom as if it sits under a barrier which the sugars, starches and enzymes will not pass. With a permeable layer, the difference in concentrations will allow the passing of those materials down below the false bottom. Stirring and recirculation will aid in that process.

Second, you can also take a gallon away from the sparge water and add it to the strike water, since you have the room. So if you take what for you is an average grain bill (let's say 13 lbs) move an extra gallon from the sparge calculated above bringing it down to 2.68 gallons and add it to the strike water, thus increasing it to 6.56 gal. This would effectively move the water to grain ratio to 2.02 qts/gal and still stay within the capacity of your mash tun.