Acidifying my Sparge water, not necessary at my alkalinity?

[FuzzeWuzze]

So doing some research into water for the first time for this brew and will doing a standard Pale Ale water profile because i have very soft water, so looking at increasing the sulfates mostly for an IPA.

The question i have is using BruNWater it shows that to get my 7.8ph, 34ppm Akalinity tap water down to 5.6ph for sparging is about 1ml of Lactic acid...but reading various posts on other forums it seems the creator of Bru'NWater states that if you have a low alkalinity in your water you dont really need to acidify it....as i understand it its because there is no buffering and it will more or less take on the PH of the rest of the water?

My question is, what is "low" alkalinity? From what i can gather here 34ppm falls into that category.

Also do these acidification of sparge water bits even matter if i am batch sparging? Aka draining my entire tun mash then dumping another ~4 gallons in? Or does it only matter if your fly sparging?

 

[SteveWPG]

You don't want the pH to go above a certain value, but the acidity of the malt helps that not happen. I acidify my sparge water to about pH 6, but unless you sparge way too long that the malt loses all its buffering capacity it's not really a problem

 

[ajdelange]

Yes, 34 ppm definitely qualifies as low enough pH that you don't have to worry about adjusting sparge water.

 

[FuzzeWuzze]

Yes, 34 ppm definitely qualifies as low enough pH that you don't have to worry about adjusting sparge water.

Thanks, is my reasoning why correct?

I've been making my way through the water book as well as all the other information i can find, so it'd be nice to know i actually did remember something useful.

 

[mabrungard]

Your reasoning is generally correct. The amount of buffering offered by that limited alkalinity is less capable of exhausting the reserve of protons in the wort and mash. Assuming you are adding calcium to that sparging water, the calcium will react with the malt phytins and create protons with the sparging water addition.

AJ seems to be a little less conservative on allowable alkalinity in sparging water than I am since he mentions around 50 ppm as an upper limit. I recommend getting the alkalinity down around 25 ppm for a little more safety margin. But I'm not sure if I'm being overly concerned. I wouldn't be surprised if allowing up to 50 ppm alkalinity does not affect beer quality.

I wouldn't bother with the acidification for a couple of the same brews and see if you can actually detect a difference from a brew that was acidified. That acid addition is really quite small.

 

[ajdelange]

The proof of the pudding is in the sparging, as they say. Everyone should probably do a sparge or two where he measures runoff gravity and pH. If your pH is acceptably low when your runoff gravity reaches the limit to which you want to take it then you don't need to acidify the sparge water. If you hit pH 6 when the runoff is still 8 °P then you do.

 

[seanppp]

With my system I'm concerned with a mash pH of 5.3 and a preboil kettle wort pH of 5.2. Should I try to hit that 5.2 by acidifying my sparge water accordingly? I don't have a pH meter yet but I've been using Bru'n Water to acidify my sparge water to an estimated 5.2 pH in the hopes that that will make the kettle wort 5.2 or so.

Is this correct reasoning? Why does nobody talk about preboil kettle wort pH when they talk about sparge water?

 

[ajdelange]

Using a spreadsheet to predict mash and in particular kettle pH is like groping in the dark - well, groping in a dimly lit room anyway. You can sort of see the shapes of things and approximately where they are but you can't really get a clear picture of what is going on. You need a pH meter for that. Sans pH meter probably the best guidance would come from the alkalinity of your water. If it isn't over 50 then you proabably don't need to worry.

Acidifying your sparge water to 5.2 won't get your kettle pH to 5.2 but it won't, under any circumstances, result in it being higher than 5.2. Keep in mind that trying to hit a particular water pH by using amounts of acid calculated from reported alkalinity can be iffy as the reported alkalinity may not accurately reflect the actual alkalinity of your water. Use the spreadheet to calculate the amount of acid to be used and add that incrementally as the pH is monitored (when you get a meter).