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-   -   Mash vs Sparge additions. (http://www.homebrewtalk.com/f128/mash-vs-sparge-additions-288874/)

flabyboy 12-22-2011 08:07 PM

Mash vs Sparge additions.
 
I have become very confused with mash vs sparge addtions in terms of water chemistry. I am leaning towards using lactic acid with my water instead of adding acid malt, mostly because I do not have a mill and storage of precrushed grain isn't ideal. I just don't understand the differences between making additions to mash vs the sparge water. If I have an equal volume for both, do I just split the addtions equally? I know some will say to add everything to the total amount of water and then split your mash and sparge water. What about the additions that don't dissolve easily in water? I am using the EZ Water Calculator online and I ended up having a nice water profile setup for a British Bitter with a mash pH of 5.5. The residual alkalinity is -81 with effective alkalinity of -31. Not sure if those are good numbers to have for this style or not. I use 2 mL in the lactic acid addition, but don't know if that is supposed to be split between the mash and sparge water. Please help this obviously dense individual in the simplist terms possible. I'm just not grasping it
:drunk:

hamiltont 12-22-2011 08:19 PM

I batch sparge and just treat my mash water. My tap water is from a well and it's great for the sparge with no adjustments. I do have high alkalinity but my logic is the sparge water is only rinsing the residual sugars from the grain, conversion has already occurred in the mash. If your sparge water is not so good you should probably adjust it for what you want in the kettle, and ultimately in the fermenter. Not sure what the protocol is for fly sparging?? Cheers!!!

flabyboy 12-22-2011 08:46 PM

Quote:

Originally Posted by hamiltont (Post 3594240)
I batch sparge and just treat my mash water. My tap water is from a well and it's great for the sparge with no adjustments. I do have high alkalinity but my logic is the sparge water is only rinsing the residual sugars from the grain, conversion has already occurred in the mash. If your sparge water is not so good you should probably adjust it for what you want in the kettle, and ultimately in the fermenter. Not sure what the protocol is for fly sparging?? Cheers!!!

Won't your hot alkaline sparge water bring the pH of your mash up to levels where tannins may be leached?

ajdelange 12-22-2011 09:37 PM

Quote:

Originally Posted by flabyboy (Post 3594315)
Won't your hot alkaline sparge water bring the pH of your mash up to levels where tannins may be leached?

It might or might not. It would depend on the alkalinity and the volume of sparge water. In traditional sparging the problem comes late in the sparge when most of the acids have been rinsed from the grains and there is nothing to hold back the pH rise.

As to the original question: acidification of mash and sparge water accomplishes two distinct things. In both cases you hope to neutralize the alkalinity of the water. Here "neutralize" means eliminate the effect of i.e. it does not mean bring to pH 7 as you might remember from high school or college chemistry. In fact it means to add enough acid to bring the pH to a value lower than 7. In the case of the mash it means adding enough acid to neutralize the alkalinity of the water and the malt to a pH of 5.4 or so. In the case of sparge water it means adding enough acid to reduce the pH of the water alone to 6 or less as if the water is at pH 6 or less it cannot possibly dilute the remaining mash (at pH < 6) to a pH > 6.

If the alkalinity of the mash water is low enough (and that's one of the main goals of water treatment - to reduce alkalinity) then the water will not dilute the remaining mash down to the point where the pH exceeds 6 before it has diluted the sugars to the point where it is not worth collecting any more runoff.

You should never have to worry about the solubility of the salts in the water you are preparing as you should never add anything to water that doesn't dissolve. In the event you find mash pH too low and choose to raise it with (insoluble) calcium carbonate you would add that to the mash as you would any other alkali.

cooper 12-22-2011 09:41 PM

AJ,

Would you recommend splitting your sparge water up into two equal amounts? For instance if you strike in with 4 gallons and you need 4 gallons to sparge with, could you do 2 equal amounts of 2 gallons and not really worry about washing away too many acids? Or would you recommend just a one-time sparge with the 4 gallons?

ajdelange 12-22-2011 09:52 PM

Quote:

Originally Posted by cooper (Post 3594454)
AJ,

Would you recommend splitting your sparge water up into two equal amounts? For instance if you strike in with 4 gallons and you need 4 gallons to sparge with, could you do 2 equal amounts of 2 gallons and not really worry about washing away too many acids? Or would you recommend just a one-time sparge with the 4 gallons?

Are you talking 2 batch sparges here?

flabyboy 12-22-2011 09:58 PM

Thanks AJ. This clears thing up a bit. How do residual and effective alkalinity fit in? What levels are acceptable?

ajdelange 12-22-2011 10:31 PM

Residual alkalinity is useful for comparing water supplies. If a water sample has a residual alkalinity of x then one can expect the pH of a base malt only mash to be 0.00168*x pH higher than a distilled water mash on the same malt (x in ppm as CaCO3). This is, of course, an approximation based on some set of assumptions and some particular malts. This number came from Kolbach's original paper writen just after WWII so may not be too current but lots of people use it and where comparison of waters is being done that's fine. When one tries to use RA to do more than compare waters and when malts other than base malts are involved then things don't work out so well.

I don't know what "effective alkalinity" is. Sounds like something from one of the spreadsheets but I can't even look at those. Since Microsoft has "improved" their software I can no longer spreadsheets from versions of Excel earlier than 2011 and I can't run versions earlier than 2011 with Apple's "improved" operating system.

cooper 12-23-2011 12:46 AM

Quote:

Originally Posted by ajdelange (Post 3594472)
Are you talking 2 batch sparges here?

Yes, basically what a person could use for one sparge and splitting I into two

flabyboy 12-23-2011 02:24 AM

Quote:

Originally Posted by cooper

Yes, basically what a person could use for one sparge and splitting I into two

This is how I sparge as well


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