Witbier chemistry questions

Calcium (Ca)	9.0	19.0	Bicarbonate (HCO3)
Magnesium (Mg)	1.0	0.0	Carbonate (CO3)
Sodium (Na)	6.0	9.0	Sulfate (SO4)
Potassium (K)	2.0	7.0	Chloride (Cl)
Iron (Fe)	0.0	0.9	Nitrate (NO3)

• I'm calculating Mash Acidification with the flaked grains being classified as base malts under grain type. Is that correct?
• Will the protein rest have any effect on lowering the pH that Bru'n Water can't/isn't calculating for?
• Based on my water chemistry and mash volume, I'm estimating on adding 4 g of gypsum and 3.5 g of CaCl2. That seems to give me a decent amount of calcium and gets my SO4/Cl ratio in the same neighborhood of a Hoegaarden profile. Seem sane so far?
• If I'm doing everything correctly so far, my estimated pH is 5.6 which seems a bit too high. Granted, I know this is just an estimation and I'll need to test, but I like to be prepared. So to get me to 5.4, it looks like I'll need to add 2mL of lactic acid (88%). Sane?
• Here's where my mind starts to melt down a bit. Adding the lactic drops my RA to -68 and alkalinity to -21. As I understand it, alkalinity is the measure of resistance to pH change. I get that if it's 0, you have no buffering capacity. What does it mean when it's negative? Are those parameters out of line? What effect will negative RA and alkalinity have on the final beer?

uberg33k said:

[*]Here's where my mind starts to melt down a bit. Adding the lactic drops my RA to -68 and alkalinity to -21. As I understand it, alkalinity is the measure of resistance to pH change. I get that if it's 0, you have no buffering capacity. What does it mean when it's negative? Are those parameters out of line? What effect will negative RA and alkalinity have on the final beer?

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Yooper said:

I wouldn't use gypsum in a witbier. You don't want the sulfate. Use caCl2 to get to 50 ppm+ of calcium or thereabouts.

Use the lactic acid to get to 5.4-5.6 at room temperature.

Don't worry about RA, just make sure your mash pH is in the range (at room temperature) and you'll be fine.

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Kaiser said:

Negative alkalinity means that you actually have to add a strong base (i.e neutralize acid) to get to the alkalinity titration point which is usually a pH of 4.3

This is expected if you add more acid than it takes to neutralize the water's alkalinity. Negative residual alkalinity also means that your water + treatment will lower the mash pH. This is what you want.

Kai

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uberg33k said:

This is what I thought at first! However, looking at Hoegaarden, the SO4/Cl is about 1.5 and Celis White is about 1.1. I can't make any sense of why unless SO4 boosts the flavor perception of the oils from orange peel, corriander, etc. like it does the perception of hops bitterness. Does anyone know for certain?

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Hermit said:

What is the source of that information?

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uberg33k said:

Up till this point, I was thinking of alkalinity as analogous to friction in the sense of classical mechanics. Guess that's out the window now.

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ajdelange said:

If you can do EE-speak (and as you mention the mechanics analog I'll bet you can). pH is like voltage (it is in fact a potential - the chemical potential of hydrogen ions) and solutions are like capacitors. If yoy have a capacitor charged to x volts and you connect it in parallel to another capacitor charged to y volts current will flow until the two are at the same voltage. The voltage and the amount of current that flow depend on the voltage difference and the sizes of the two capacitors. Alkalinity is akin to the capacitance. If the target capacitor is large a lot of current has to flow to bring about a desired voltage change. Similarly if water has high alkalinity a lot of protons have to flow.

As with an electrical circuit there is a reference pH which defines all this. WRT alkalinity it is 4.3 or 4.5 or some number close to that. Just as you can charge a capacitor to negative voltage (less than the reference of 0) you can protonate a system to less than the reference pH.

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helibrewer said:

For my Wit, the SO4/Cl ratio was 1.6
My profile looked like this:
Ca-52, Mg-20, Na-11, SO4-135, Cl-80, HCO3-147

I did acidify the mash with 25% Phosphoric Acid

Loved the beer and will brew it again.

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uberg33k said:

Ok, that at least makes me feel like I'm not completely off base. The problem is still why is the ratio in that zone? Like Yooper said, I would think tasting a witbier that it's all CaCl2, yet reading up on it seems to indicate the ratio is more along the lines of an IPA. I don't understand what's going on with that.

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mabrungard said:

So I feel that to get an otherwise sweet beer to finish a little more dryly, having a modest level of sulfate is OK. In fact looking at profiles like Jever, Koln, Dusseldorf in Germany and Hoegaarden and Flanders in Belgium are proof that malt-focused styles can be successfully created with modest sulfate to compliment the chloride.

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mabrungard said:

While I'll concur that sulfate is a scary addition in a beer that is not focused on bitterness, there still is a place for it. AJ has been harping about keeping sulfate out of any European Lager with noble hops. I'm not sure I buy that since there are plenty of breweries in Germany with modest sulfate levels (50 to 80 ppm) and they are probably using noble hops and creating successful beer.

I have a problem with the concept of sulfate 'enhancing bitterness'. In my opinion, sulfate enhances dryness in the finish and not necessarily bitterness. Now, I will agree that the net effect of a drying finish is to allow the bittering to come through much more strongly in the finish, but its a consequence, not a cause.

So I feel that to get an otherwise sweet beer to finish a little more dryly, having a modest level of sulfate is OK. In fact looking at profiles like Jever, Koln, Dusseldorf in Germany and Hoegaarden and Flanders in Belgium are proof that malt-focused styles can be successfully created with modest sulfate to compliment the chloride.

Don't be afraid of wive's tales and bad lore.

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Yooper said:

I was mainly talking about the S04:Cl ratio- which I feel is unimportant. I don't make many wits (don't care for wheat beers) but I think a high-sulfate level in them can taste a bit harsh. That was all I was saying!

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