Lemon juice should act as a good acidifier for ph adjustments, IMO, no drawbacks as far as I can see. I’m considering trying it out. Any helpful warnings or opinions?
I don’t think it will hurt. All I have read is the preference for Phosphoric Acid because it impacts the flavor the least. Lemon Juice may have more of a flavor impact. Honestly though, I have never set up a side by side experiment; only trusted community sentiments.
I just brewed a wheat and used phosphoric acid. That might have been a good alternative in a beer that can often have lemon added to it anyway. Next time perhaps.
A little beer gnome tells me that the juice of one lemon (1/4 - 1/3 cup maybe) contains about 3g of citric acid.
When you use an acid to neutralize a base, the neutralized hydroxyls are being replaced by the anion of the acid. Sulfuric acid makes sulphate, hydrochloric acid makes chloride, phosphoric acid makes phosphate, citric acid makes citrate. The reason phosphoric acid is usually preferred is the large amount of phosphate already present in the malt. If your water is low in sulfate, sulfuric acid might be a good idea. Same with hydrochloric.
I don’t know what citrate taste like, but my guess is if it tasted good in beer, people would use it over other acids.
I think citric acid has more of a tart flavor than lactic acid, which is why lactic is used and not citric.
I’ve used citric acid for the last 15 brews. I have never noticed any flavour that I could attribute to the acid. I only use a couple grams for my water but I’m more than happy using citric if I have to. I did buy phosphoric acid because that’s what all the cool kids were doing but I would use citric if I couldn’t find anything else. I think it would depend on the beer. For a light CAP or wheat beer, I think the presence of lemon could be very complimentary. In a porter…not so much.
You must get much better lemons than we get here, because it’s a damn big lemon that gets us 1/4 cup of juice. I assume the citric acid concentration is more accurate per volume, and not per lemon?
That 3g number was per lemon, I was guessing at the juice volume. Shame on me for guessing. But your right, concentration per volume would be better, and concentration might vary depending on growing conditions and variety.
Here’s a better answer - 1.44g/oz for fresh lemon juice, 1.10g/oz for bottled lemon juice.
Citric acid can be used in beer to adjust flavor and pH of the beer, but be careful with the additions as it can have an adverse effect on the flavor profile of the beer if it is added in high dosages. One way to better understand the flavor impact is to dose some commercial examples at prescribed rates and scale it up accordingly.
Oh, that’s cool. I was serious about the better lemon thing though, because I noticed the same thing with the key limes we get - they are much smaller than the ones that Jeff gets, with a lot less juice. 
Thanks for the ref.
I tried out the lemon theory. Good news. :) As it turned out, the juice from 2 lemons, squeezed into 15 gallons of water, reduced the ph from 7.5 to 5.5, about a point a lemon. It was easy, predictable, controllable. No trace of flavor in the final wort product, and I doubt there ever will be. I like it, one less chemical to worry about. Next time I may use bottled lemon juice, but I’m sold.
Am I the only one using sauer malt?
I have used acidulated malt when the need arises. It works very well. Plus, you don’t need much to bring down the pH of the mash.
That’s fine, but is it useful in your HLT water?