Adjusting sparge water

I'm a bit puzzled about the sparge water PH.

Am I understanding things right, that you guys adjust with fx. 2ml lactic in the sparge to drop it from fx. 7.8 to a 5.something ? (Which is my tap water ph).
Doesn’t the large amount of lactic cause even more off flavors vs. astringency/tannin extraction from high ph, if I’ve already added let’s say 1 ml. to the mash?
In my last 2 wits I tried with 3ml. and 4 ml all in all, and could certainly taste the sour lactic twang.

Many brewers acidify their sparge water when it really isn't necessary. The only reason to acidify sparge water is if you fear excessive tannin extraction from the grain husks. Extraction of phenols (tannins) is enhanced at higher pH because they are weak acids. It is not like turning on a light switch but rather the increase takes gradually over a range of pH values. Most brewers seem to think that if you stay below pH 6 that phenol extraction is under control and that is a reasonable number. If you accept 6 then there is no reason to acidify your sparge water unless you observe pH > 6 towards the end of your sparge. This is more likely to happen with highly alkaline water (with which you shouldn't be brewing in any case) than with softer (less alkaline) water. If you are not experiencing haze or roughness/astringency in your beers you are not extracting phenol and don't need to acidify your sparge water. Also, the effects of extracted tannins pass with time. This is one of the main reasons for lagering lager beers.

What you should do is monitor runoff gravity and pH during a sparge. If the pH hits 6 when the gravity is less than say 5 °P or less just stop sparging at that time as the additional extract obtained by sparging down to 2 °P just isn't that much.

If you feel you cannot give up those extra couple of degrees then you can try sparging with water that you have diluted 1:1 or so with RO or DI water. This will let you go lower before hitting pH 6. If you feel you must acidify then acidify only to 6 and use a flavor neutral acid like phosphoric or hydrochloric or even, if you like beers with lots of sulfate, sulfuric. Be sure to use food grade acid and be careful if you must buy them in concentrated form. They are all potentially dangerous.

There is not a fixed quantity of acid that is needed per unit of sparge water. The quantity of acid needed to drop water pH to a lower pH is highly dependent upon the water's starting alkalinity. Bru'n Water has an effective sparge water acidification calculator (thanks to AJ) that makes it easy to calculate how much of a particular acid you will need to add to a starting water with a known starting pH and alkalinity.

If the starting water has very high alkalinity, then its possible that a significant quantity of acid will be needed. That amount may have a taste impact. Switching to other acids such as phosphoric or sulfuric might alleviate the taste issue.

Thanks for the advices 

Don’t think my Plato drops down to 5 points, last batch I stopped at 7, did not need more worth and sparged with the usual amount.
But must add to this, that I’ve just bought a refractometer and used it for the past 4 brews, so cannot speak for the ones before that.

My problem is mainly in the dark beers, last batch I added 3g c.c. and 1 gypsum to the mash of a very roasted porter. Ph dropped extremely, Almost around 4.5 at the end of mashing, don’t know if that’s the reason, but It became quite astringent. (Not because of the 12% roast I believe) .

My sparge water has never been adjusted, and I'm starting to believe that it’s the reason to the astringent taste. (se water profile below)

Calcium 37mg
Sulfat 11mg
Magnesium 5.4mg
Sodium 17mg
Chloride 19mg
HydrogenCarbonat(bicarbonat) hydrogen na 148
Ph 7.8

As you can probably read I’m no expert, read tons of info on water adjustment, but it’s just such a big topic. Guees there’s quite a reason to why people need a chemist education sometimes. There are so many aspects and factors.

In general I would say, that I need a little more round mouth feel, without losing the “roastyness”. Actually succeeded in that with a full boil test batch once, and therefore also suspect the sparge water to be the reason. But a full boil is hopeless when doing a full size batch so would really like to know what is needed for my sparge.

Thanks again for your great inputs and explanations.

By the way, looking forward to be trying brunwater for my next batch... a RIS of course.

For a porter or stout with your water the pH should be just about right or a wee bit high. Addition of acid would not be necessary as you have seen. Even assuming your strips are reading 0.3 low an indication of 4.5 implies a mash pH of 4.8 which is quite a bit low. Don't know if that would cause astringency as I have never explored the "too low" end of the mash pH reqime though I have quite a bit of familiarity with the "too high" end. By all means obtain a meter and get pH under control as a first step. Then have a look at reducing the amount of roast malt and/or increasing chloride.

ajdelange said:

For a porter or stout with your water the pH should be just about right or a wee bit high. Addition of acid would not be necessary as you have seen. Even assuming your strips are reading 0.3 low an indication of 4.5 implies a mash pH of 4.8 which is quite a bit low. Don't know if that would cause astringency as I have never explored the "too low" end of the mash pH reqime though I have quite a bit of familiarity with the "too high" end. By all means obtain a meter and get pH under control as a first step. Then have a look at reducing the amount of roast malt and/or increasing chloride.

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Would you think i would need to adjust the sparge to say 6ph ? to be sure the high 7.8 sparge dosen't extract any tannins.

While your alkalinity is respectable I don't think you will need to acidify - especially if you terminate collection at 7 °P

Super...

But if i go lower, as i do sometimes, would a ph6 do? and would it be possible to use citric acid instead of Lactic, without getting off flavours as with Lactic, or is just another off flavour then.

And what about treatment when brewing Pilsners, i was thinking maybee pre-boiling water, that would make 61ppm less Bicarbonate right?

Bonde said:

But if i go lower, as i do sometimes, would a ph6 do? and would it be possible to use citric acid instead of Lactic, without getting off flavours as with Lactic, or is just another off flavour then.

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Yes, though you might not need to even then. And yes, citric will work but it has its own characteristic flavor. There was a time when the early home brewing books advocated adding a tsp or so of citric to every brew.

Bonde said:

And what about treatment when brewing Pilsners, i was thinking maybee pre-boiling water, that would make 61ppm less Bicarbonate right?

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Bohemian Pilsners are brewed with very soft water. You would not want to add anything to your water for a Boh Pils. In fact you would want to dilute it with a large proportion of RO water. Here acid usually in the form of sauermalz is required to get mash pH low enough.

With German Pils higher mineral content is sometimes used.