Build Water Profile for Post boil volume or Total Water Volume?

[Brewmegoodbeer]

Hello all,

I brew 5 gallon batches. I typically build my water profile using the total water volume including strike and sparge water (~8 gallons). Now knowing that ions do not evaporate, its bothering me knowing that my water profile could be more concentrated than I think post boil. My pre boil volume is 7 gallons. I end up with 5.25 gallons in the fermenter. I have a 4% cooling shrinkage, and lose about 0.25 gallons to trub, and im thinking about 0.25 gallons to evaporation when cooling the wort. Im supposing i would count the evaporation when cooling part of the total evaporation of water so about 1.25 gallons are being lost to evaporation which puts me at about an 18% evaporation. Should i be concerned about this and make my ion concentration considerable to my post boil, post cooling volume to avoid over concentration of minerals? Am I over thinking this?

 

[Big Monk]

Hello all,

I brew 5 gallon batches. I typically build my water profile using the total water volume including strike and sparge water (~8 gallons). Now knowing that ions do not evaporate, its bothering me knowing that my water profile could be more concentrated than I think post boil. My pre boil volume is 7 gallons. I end up with 5.25 gallons in the fermenter. I have a 4% cooling shrinkage, and lose about 0.25 gallons to trub, and im thinking about 0.25 gallons to evaporation when cooling the wort. Im supposing i would count the evaporation when cooling part of the total evaporation of water so about 1.25 gallons are being lost to evaporation which puts me at about an 18% evaporation. Should i be concerned about this and make my ion concentration considerable to my post boil, post cooling volume to avoid over concentration of minerals? Am I over thinking this?

When I evaluate the "Finished" (post-boil) profile in my own spreadsheets, I use ( Strike Volume - Boil-Off ) as the volume input for the equation to cover evaporation. I onlt have around 7-8% boil-off so it doesn't make much of a difference but as you get up there you'll see an increase in mineral concentration.

For instance, say I have 34.73 liters of strike volume and I boil-off 2.125 liters. I add 1 gram of Gypsum to the strike volume:

My mash water concentration of Calcium and Sulfate will be:

Ca (Mash) = (232.78 * 1)/34.73 = 6.7 ppm
SO4 (Mash) = (557.94 * 1)/34.73 = 16.1 ppm

After removing boil-off:

Ca (Mash) = (232.78 * 1)/32.60 = 7.14 ppm
SO4 (Mash) = (557.94 * 1)/32.60 = 17.11 ppm


I No-Sparge so for you the calcs will be different depending on if you dose sparge water with minerals, boil-off %, etc. but the spirit of the calcs is the same.

 

[TheHopfather]

Bru'n Water asks for 3 water volumes. Mash, sparge and total batch (finished, in carboy volume). Pretty sure it is doing all of this for you.

 

[Big Monk]

Bru'n Water asks for 3 water volumes. Mash, sparge and total batch (finished, in carboy volume). Pretty sure it is doing all of this for you.

Unfortunately it does not. You have to do it yourself. Total batch is used for color, etc.

 

[mabrungard]

Bru'n Water asks for 3 water volumes. Mash, sparge and total batch (finished, in carboy volume). Pretty sure it is doing all of this for you.

Those inputs are independent. They do not account for evaporation losses. If your system evaporation is more than about 15%, then you probably do need to base your mineral additions on the post-boil volumes in order to avoid excessive mineralization.

 

[Brewmegoodbeer]

Those inputs are independent. They do not account for evaporation losses. If your system evaporation is more than about 15%, then you probably do need to base your mineral additions on the post-boil volumes in order to avoid excessive mineralization.

Thanks Martin! I was really hoping that you would respond to my thread, as you are the brewing water "god"! haha. Based upon my current numbers, my evaporation loss at end of boil is 16.6%. Would I additionally account "cooling shrinkage" as evaporation as well (4%)? I lose about .33 gallons to trub and chiller, so there is additionally evaporation there when chilling with a wort chiller. I think I'll have to go with just building my water profile based upon my post boil volume to get the most accurate mineral concentration. Now i'm trying to figure out the best way to do this. I like to add my minerals into my strike water and then into my kettle after sparging. I'm thinking that I'll just build the water as normal for my strike water volume, then reduce the concentration that I put into the kettle before boiling. My current recipe that I am making today calls for a total of 4 gallons of water for strike which ill build the water for this volume normally, then there is an additional 4.11 gallons of sparge water that creates a 7 gallon pre boil volume. about 0.9 gallons of water is lost based upon grain absorption for this recipe, so im figuring just as a rough estimation, about 3.5 gallons of the treated strike water makes it into the kettle for preboil volume and the rest is untreated sparge water. This would leave me with about 3.5 gallons of water that has been untreated (again very rough estimations). now if I subtract my boil evaporation from the untreated water (3.5-1.16) Im going to treat only about 2.34 gallons of the water thats in my preboil volume to account for that evaporation loss. In the end, would this bring my close to a ball park accurate mineral concentration? Of course, there would be error, but as long as that error is within 15%, I should be good. Is there a more reliable way to do this?

 

[Big Monk]

Based upon my current numbers, my evaporation loss at end of boil is 16.6%.

Are you sure? Keep in mind, the only evaporation based loss is from boil-off.

Would I additionally account "cooling shrinkage" as evaporation as well (4%)? I lose about .33 gallons to trub and chiller, so there is additionally evaporation there when chilling with a wort chiller.

Wort shrinkage isn't evaporation based loss. You start with a volume of chilled water at the beginning of the brew day and then end with a chilled wort in the fermenter. Expansion and contraction of wort is only of use for determine accurate volumes during the brewday.

Also, volume loss to equipment isn't evaporation based loss.

I think I'll have to go with just building my water profile based upon my post boil volume to get the most accurate mineral concentration. Now i'm trying to figure out the best way to do this. I like to add my minerals into my strike water and then into my kettle after sparging. I'm thinking that I'll just build the water as normal for my strike water volume, then reduce the concentration that I put into the kettle before boiling. My current recipe that I am making today calls for a total of 4 gallons of water for strike which ill build the water for this volume normally, then there is an additional 4.11 gallons of sparge water that creates a 7 gallon pre boil volume. about 0.9 gallons of water is lost based upon grain absorption for this recipe, so im figuring just as a rough estimation, about 3.5 gallons of the treated strike water makes it into the kettle for preboil volume and the rest is untreated sparge water. This would leave me with about 3.5 gallons of water that has been untreated (again very rough estimations). now if I subtract my boil evaporation from the untreated water (3.5-1.16) Im going to treat only about 2.34 gallons of the water thats in my preboil volume to account for that evaporation loss. In the end, would this bring my close to a ball park accurate mineral concentration? Of course, there would be error, but as long as that error is within 15%, I should be good. Is there a more reliable way to do this?

Let me throw a quick sheet together for you.

 

[Big Monk]

@Brewmegoodbeer

Here you go:

http://www.lowoxygenbrewing.com/wp-content/uploads/2019/01/Minerals-and-Boil-Off.xlsx

Should allow you to:

a.) Handle No-Sparge;
b.) Allow you to account for Sparge dilution without adding minerals directly to kettle;
c.) Allow you to add strike minerals and kettle minerals;
d.) Account for evaporation from boil off