*Advice: MLT Dead Space and Mashing Out

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mkravitz13

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hey everyone,

while this may be my first ever post, this is absolutely not my first time to homebrewtalk. ive been frequenting these forums for months and months for sound advice that have made me lots of excellent homebrewed beer. i love forums!

been searching everywhere for a solid answer to a question without getting a firm response.

in my 5 gallon MLT, I have 0.25 gal of deadspace.

I brew 2.75 gal batches which requires about a 3.75 gal boil for my system.

I'd like to batch sparge the denny way.

seasoned veterans and homebrewers, please lend me some advice!

Which water volume should I adjust to account for my deadspace?
  • strike water volume?
  • mashout water volume?
  • sparge water volume?
 
Adjust the strike water only.
The first water addition will fill the dead space, and stay there during all other water additions.
 
Adjust the strike water only.
The first water addition will fill the dead space, and stay there during all other water additions.

hmm. thats what I saw beersmith suggested as well. but what I dont get is by adding more water to my strike volume (to fill the deadspace) doesn't that in turn change my target water/grist ratio?
 
anyone? ive seen discrepencies between a bunch of different mash/sparge calculators. some say add the deadspace to the strike volume. others to the mash out volume.

but again, wont adding water to the strike volume change my target water/grist ratio??? :confused::confused::confused:
 
I may be completely missing something, but I don't think that you adjust up like that. Otherwise, people using huge rectangular coolers would be using a ton of water, which would just kill the ratio. In effect, the size of cooler you own would dictate the kind of beer you could make, and that just doesn't make sense.
 
If you adjust the strike water and nothing else, your ratio will be off, well, that seems logical. Subtract equal amount of sparge water or add extra time to the boil to make up for the extra water? Don't take this as a statement, I'm a beginner trying to figure all this stuff out. But I think I understand your logic and how making just that one adjustment, without counteracting it, would throw things off.
 
I may be completely missing something, but I don't think that you adjust up like that. Otherwise, people using huge rectangular coolers would be using a ton of water, which would just kill the ratio. In effect, the size of cooler you own would dictate the kind of beer you could make, and that just doesn't make sense.


I think I may be missing something too... doesn't make sense to me either.
 
anyone? ive seen discrepencies between a bunch of different mash/sparge calculators. some say add the deadspace to the strike volume. others to the mash out volume.

but again, wont adding water to the strike volume change my target water/grist ratio??? :confused::confused::confused:

It will change the ratio but not enough to even worry about. I read where someone conducted a experiment and added all the strike and sparge water all at once and then just drained it and did not suffer any efficiency problems. If any problem would arise I would think it would be come from having a mash to thick instead of to thin.

I do not worry any more about it with my set up. I know I have to about fill my tun up twice to get my boil volume. Once for the strike and once to sparge. Last night doing that I got 85% efficiency when I brewed and the mash seemed kind of thin at first but hey it worked so I have run with it for over a year now
 
hmm. thats what I saw beersmith suggested as well. but what I dont get is by adding more water to my strike volume (to fill the deadspace) doesn't that in turn change my target water/grist ratio?

It depends...is there grain in your deadspace as well, or is it underneath a false bottom (for example). In either case, it depends on exactly what you're trying to do in measuring your water-to-grist ratio.

Personally, I figure out my water:grist ratio excluding the deadspace under my false bottom because I'm mostly interested in the mechanical stiffness of my mash. If you're interested in something else, you might need to think about it differently.
 
hmm. thats what I saw beersmith suggested as well. but what I dont get is by adding more water to my strike volume (to fill the deadspace) doesn't that in turn change my target water/grist ratio?
Yes, that's why it's undesirable to have dead space


I may be completely missing something, but I don't think that you adjust up like that. Otherwise, people using huge rectangular coolers would be using a ton of water, which would just kill the ratio. In effect, the size of cooler you own would dictate the kind of beer you could make, and that just doesn't make sense.
People who use coolers usually use a bazooka screen, or a slit-manifold, and therefor have nearly 0 dead space.

Where exactly is the dead space?
By dead space, do you mean wort that will never be collected?
 
What is missing is that the dead space water has a bigger impact on smaller grain bills (like when you do smaller batches like the OP). Dead space volume is fixed.

e.g.
With 6 lbs of grain, 1 quart (0.25 gallon) of dead space water increases the mash ratio goes from 1.25 to 1.4qt/lb.

With 12 lb of grain, mash ratio goes from 1.25 to 1.3 qt/lb.


The other thing to note is that a larger cooler may not have a proportional increase in dead space size.

Even though its not ideal, I agree that you need to account for it in the strike water since this is when that volume is first filled.
 
I don't know if it would be enough to make a difference or not, depends on how much dead space. But if I were you, anything you add to the strike, subtract from the sparge.
 
I have 2 gal dead space under my false bottom. I add them to my strike water. It works. Efficiency is %70+. Beer comes out good. I do 5gal batches.
 
but again, wont adding water to the strike volume change my target water/grist ratio??? :confused::confused::confused:

still have not bought and converted a cooler yet, doing all-grain in a Zapap MLT. last batch I was doing a fairly thick mash, 1:1 qt/lb and there was definitely not enough water because the deadspace sucked it up. had to add another gallon to make up for it.

I don't see any other way around it.
 
I don't know if it would be enough to make a difference or not, depends on how much dead space. But if I were you, anything you add to the strike, subtract from the sparge.

I wouldn't do this; dead space is by definition unrecoverable. If you subtract from the sparge then you'll be short at the end. I would add to the strike, not worry about the small different in mash ratio, and collect according to your process.

Although unrecoverable, the dead space will be "washed" of sugars, similar to the grain bed. Its not like you'll have 0.25 gallons of first runnings stuck under there. It will be the gravity of the end of your last sparge (or should be close).
 
I wouldn't do this; dead space is by definition unrecoverable. If you subtract from the sparge then you'll be short at the end. I would add to the strike, not worry about the small different in mash ratio, and collect according to your process.

Although unrecoverable, the dead space will be "washed" of sugars, similar to the grain bed. Its not like you'll have 0.25 gallons of first runnings stuck under there. It will be the gravity of the end of your last sparge (or should be close).

This makes sense.

I also feel better now, as to start with, I was thinking headspace, not deadspace.

I am such a noob.
 
What is missing is that the dead space water has a bigger impact on smaller grain bills (like when you do smaller batches like the OP). Dead space volume is fixed.

e.g.
With 6 lbs of grain, 1 quart (0.25 gallon) of dead space water increases the mash ratio goes from 1.25 to 1.4qt/lb.

With 12 lb of grain, mash ratio goes from 1.25 to 1.3 qt/lb.


The other thing to note is that a larger cooler may not have a proportional increase in dead space size.

Even though its not ideal, I agree that you need to account for it in the strike water since this is when that volume is first filled.

thanks for responses everyone. but what broadbill is saying is exactly what im dealing with here! with my small batches (which i love) even a quart of deadspace throws all my numbers off and vastly increases my mash ratio.

if add 0.25 gallons to my mash-out water, im worrying that I'll way overshoot mash out temp (~170C)

to everyone else out there: my dead space is beneath my SS brain and yes, grain can go down there unlike a true false bottom. unless i tip the cooler, that wort will never be drained.
 
thanks for responses everyone. but what broadbill is saying is exactly what im dealing with here! with my small batches (which i love) even a quart of deadspace throws all my numbers off and vastly increases my mash ratio.

if add 0.25 gallons to my mash-out water, im worrying that I'll way overshoot mash out temp (~170C)

to everyone else out there: my dead space is beneath my SS brain and yes, grain can go down there unlike a true false bottom. unless i tip the cooler, that wort will never be drained.

Let me put a finer point on this:

A quart of deadspace isn't throwing your numbers off that much (I'm assuming you are doing 6-7lbs of grain, right?)....I wouldn't worry about 1.25 vs. 1.4 or even 1.6.

The BIAB guys are using ALL of their water to mash in and not sparging at all, making perfectly good beer.

I don't know if you gain much by changing where you account for the dead-space.....regardless of where you put it "on-paper" that void is filled when you first fill the MT (i.e. mash).

The other option is to tip the cooler and retrieve that volume. I don't see any down-side to this, and it makes the calculations more straight forward.
 
Heck I try and over shoot the mashout temp since it means less time on the propane. I think you are worrying way to much about it since you cannot change your deadspace you are going to have to make up for it somewhere. Only time I would worry about the mash out being to hot is if the PH had dropped way down and you were extracting tannins.

If I could I would would use a larger cooler and not sparge at all just dump it all in at once and be done with it. Plenty of people do just that and have no problems at all
 
I understand now, that's why you simply add it to the strike water and no worries after that. So the OP just adds an quart of strike water if he doesn't want to tip the cooler.

Thank you, I learned something today. And more reason to finish my sink mash tun, has a nice slope to the bottom drain and tubing, no dead space.
 
Let me put a finer point on this:

A quart of deadspace isn't throwing your numbers off that much (I'm assuming you are doing 6-7lbs of grain, right?)....I wouldn't worry about 1.25 vs. 1.4 or even 1.6.

The BIAB guys are using ALL of their water to mash in and not sparging at all, making perfectly good beer.

I don't know if you gain much by changing where you account for the dead-space.....regardless of where you put it "on-paper" that void is filled when you first fill the MT (i.e. mash).

The other option is to tip the cooler and retrieve that volume. I don't see any down-side to this, and it makes the calculations more straight forward.

broadbill, you rule. thanks for helping me here. im located not to far from you btw, in burlington, vt. tons of snow here...

my last recipe called for just about ~5.5lb grain. 1.25 is a standard mash ratio and id like to stay in that area if i can.

just from observing guides all over the web, all of them say OK, I have 10lb of grain and @1.25qt/lb, that means i'll need 12.5 qt of strike water. not 12.5 qt + 1 gal for my dead space!

there's just got to be plenty of mashers out there who use ss braids and have dead space in their coolers!!
 
problem I had is not with the recoverable water, it's the thickness of the mash

brewing a PA and, following Ray Daniels recommendations in Designing Great Beers to strike at .9 to 1 ratio. So for 12.5 lb grain bill, I strike at 12.5 quarts and when I finish putting in the grains, it's like trying to stir cement. dang near snapped my mash paddle in ½

this was 6 gallon Zapap MLT, & I was pushing the limits in it anyway. what little strike water I had started splashing up through the space between the 2 buckets
 
Heck I try and over shoot the mashout temp since it means less time on the propane. I think you are worrying way to much about it since you cannot change your deadspace you are going to have to make up for it somewhere. Only time I would worry about the mash out being to hot is if the PH had dropped way down and you were extracting tannins.

If I could I would would use a larger cooler and not sparge at all just dump it all in at once and be done with it. Plenty of people do just that and have no problems at all

single infusion w/ no sparge? id like to be a sparger!

as for overshooting mashout temp, i dont want to bother with taking pH readings. if it gets as close to 180F (from adding my deadspace to my mash out volume), im assuming I'll likely extract lots of astringent compounds.

i want my brew days to be consistent and reliable. in all honesty, does using 1.25 ratio and/or a 1.5 ratio really make that much difference with wort quality and reaching target OG?
 
single infusion w/ no sparge? id like to be a sparger!

as for overshooting mashout temp, i dont want to bother with taking pH readings. if it gets as close to 180F (from adding my deadspace to my mash out volume), im assuming I'll likely extract lots of astringent compounds.

i want my brew days to be consistent and reliable. in all honesty, does using 1.25 ratio and/or a 1.5 ratio really make that much difference with wort quality and reaching target OG?

To be honest even with just short of boiling water I do not get much over 170 in the pot. As far as leaching tannins you are going to be using the same amount of water sparging or not sparging to get the same boil volume. And talk about consistent and reliable knowing that a pound of grain will absorb x amount of water you could multiply that by the pounds of grain add the dead space and boil volume and hit your targets dead on every time with out running the risk of leaching tannins. Not to mention the greater mass will hold its temp at a steadier rate over a longer period of time meaning you gain more consistency over your mash.

With my smaller cooler and 9 pound grain bills I do not even measure the water anymore because I know where I need to be in the cooler level wise to get my boil volume. And just because I like to play it safe I end up with maybe a quart of water left over in the tun in case I am off a little bit.
 
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