Reducing alkalinity with slaked lime

[Yooper]

Ok, all decanted and pH adjusted down to 8. I'm just waiting for the apatite to settle and then I'll check the GH/KH.

I got TONS of sediment. Like the bottom 1.5 gallons of both vessels was all precipitate.

I'm still not convinced that this is easier than an RO system, but so far so good.

 

[Nateo]

I'm still not convinced that this is easier than an RO system, but so far so good.

I wouldn't claim it's easier. It's cheaper and more convenient for me. YMMV, but hey, at least you gave it a shot, even if you decide it's not for you. It did take me doing it a few times before I hit my stride.

 

[pjj2ba]

I don't add extra Ca when I treat with lime. I also don't add enough lime to get the pH up to near 12 (~ 3 gm/10 gal). I can't recall my exact #'s but we have fairly high Ca in our water (I need to look it up to refresh my memory) After pumping off the ppt., I never get any extra precipitate when I use phosphoric acid to bring the pH down.

I'm a bit fuzzy my recollections on the reaction between Ca and PO4, (other than the product is really insoluble) but I recall the formation of a ppt. was not something that always happened. I used to make a lot of media for growing plants on defined media in petri plates or for mineral nutrition experiments (with lots of Ca and PO4). If you mixed the components in the wrong order, the Ca and PO4 would combine, but if you did it the other way, then it didn't. I can't recall the details though.

I keep meaning to try added some extra Ca when I add the lime, but haven't yet. Maybe for this next batch and I'll see if the extra Ca reacts with the phosphoric acid when I add it

 

[Nateo]

I don't add extra Ca when I treat with lime. I also don't add enough lime to get the pH up to near 12. . . I never get any extra precipitate when I use phosphoric acid to bring the pH down.

If I understand AJ's explanation correctly, you'll only get extra precipitate if you add a whole bunch of lime. If I only raise the pH to 11 I don't get much extra precipitate, but it takes much longer for it to drop clear. At 12 it drops clear much quicker, but I get a fair amount of extra precipitate when I add the acid.

 

[Yooper]

I don't add extra Ca when I treat with lime. I also don't add enough lime to get the pH up to near 12 (~ 3 gm/10 gal). I can't recall my exact #'s but we have fairly high Ca in our water (I need to look it up to refresh my memory) After pumping off the ppt., I never get any extra precipitate when I use phosphoric acid to bring the pH down.

I'm a bit fuzzy my recollections on the reaction between Ca and PO4, (other than the product is really insoluble) but I recall the formation of a ppt. was not something that always happened. I used to make a lot of media for growing plants on defined media in petri plates or for mineral nutrition experiments (with lots of Ca and PO4). If you mixed the components in the wrong order, the Ca and PO4 would combine, but if you did it the other way, then it didn't. I can't recall the details though.

I keep meaning to try added some extra Ca when I add the lime, but haven't yet. Maybe for this next batch and I'll see if the extra Ca reacts with the phosphoric acid when I add it

I added the extra Ca because of AJ's explanation that I can only drop the alkalinity as much as I can drop the calcium. I'm paraphrasing, of course! But the jist of it was that my calcium is relatively low, so I'd be limited to dropping less alkalinity. Since I use CaSo4 and CaCl2 anyway in the beer as additions, I just added them prior to the lime treatment. Calcium will drop some, but the chloride and sulfate will remain and I'll have enough calcium in the brewing water. At least, that was the way I understood it!

I just checked the GH/KH. The KH was 3*- which should be around 56 ppm if I read the conversion correctly. That's a huge reduction. But I must not be ready yet, as the GH was off the charts!

 

[mabrungard]

I'm still not convinced that this is easier than an RO system, but so far so good.

Definitely NOT easier, but orders of magnitude cheaper if you don't count your labor. If your water is suited to it, lime softening is excellent for brewing and potentially better for brewing than RO. That last statement is really dependent upon the concentrations of other ions (Na, SO4, and Cl) being modest or low.

Lime cost...$6 to treat thousands of gallons of water
Treatment vessel costs...depends, but I like Nate's garbage can idea

RO unit purchase...$100 to $200
Membrane and filter costs...maybe $10 per 1000 gals, but it depends on the water
Tank or vessel to hold RO water...depends. Garbage can is still looking good!

When the water is suitable, the selection of treatment method will boil down to your desired level of effort. RO is almost effortless and you will have to work with lime softening.

 

[Nateo]

I bought my phosphoric from dudadiesel. 1L of 85% was about $18 with shipping. That diluted out to about 9L of 10%, which will probably last me forever.

 

[afr0byte]

Ahh, I love beer geekery.

 

[Borisfa]

Sorry for reborn this threat.

My water has Alkalinity 186,5 mgCaCo3/L and 63,6 mg/L of Ca and 3,41 mg/L of Mg. Am I candidate to use slaked lime to reduce alkalinity?

I try do a simulation on Braukaiser spreadsheet and I have a result that I would like to share with you, because I intent to use next weekend and I would like to be "sure" to use without to do a mistake.

I see that I should do:

Add 150 ppm of Gypsym
Add 50 ppm of CaCl2 - my water Cl content is 2,12 mg/L
Add 160 ppm of Slacked Lime - Ca surpluss=38ppm

This water is for a American IPA and SO4/Cl=3,3/1 (SO4 is zero on my water).

Are they correct my additions as reported above?

Thanks,

Fabiano da Mata

P.S.: Sorry for my English

 

[ajdelange]

Your alkalinity is 185,5 ppm as CaCO3 or 3,71 mEq/L. You calcium is 63,6 mg/L equivalent to 3,18 mEq/L. The reaction by which lime decarbonates is

Ca++ + 2HCO3- + Ca++ + 2(OH)- ---> 2CaCO3 + 2H2O.

Thus for each mEq of alkalinity (bicarbonate) or calcium to be removed you will need a mEq of calcium (half a mmol) and a mEq of (OH)- (1 mmol) from 1/2 mmol of Ca(OH2). As a general rule you can decarbonate down to 1 mEq/L of whichever is the less of Ca++ or alkalinity. Here that is calcium so you should be able to get it down to around 1 mEq meaning removing 2,18 mEq. The same amount of alkalinity will be removed so that there will be 3,71 - 2,18 = 1,53 mEq/L alkalinity left. To remove 2,18 mEq of calcium and alkalinity requires 1,09 mmol/L Ca(OH)2 or 80 mg/L.

To remove more alkalinity in a case like this one add supplemental calcium until the calcium hardness and alkalinity are at least equal. If you add 3,71 - 3,18 = 0,53 mEq/L calcium then you should be able to reduce both calcium and alkalinity to 1 mEq/L i.e. both are reduced by 2,71. This would require 1,35 mEq/L or 100 mg/L.

With precipitation reactions like this reactions often aren't as expected. It is best to make several trial solutions, add different amounts of lime and see which dose gives the best reduction.

 

[Borisfa]

@ajdelange, thanks for your reply. Some doubt:

- How change mg/L to mEq/L?
- After remove the alkalinity, some Ca++ will be consumed to precipitate as CaCO3, and now to other questions:
- Should I remove this precipitate to use this water on mash tun?
- Should I add more Ca++ source to adjust Ca++ on the water?

- How is the procedure (how long should be the settling time, should stir,....?) when I add lime? Should I dilute lime before add (make a solution or add powder)? Alis there a better temperature to do?

Thanks,

Fabiano

 

[afr0byte]

@ajdelange, thanks for your reply. Some doubt:

- How change mg/L to mEq/L?
- After remove the alkalinity, some Ca++ will be consumed to precipitate as CaCO3, and now to other questions:
- Should I remove this precipitate to use this water on mash tun?
- Should I add more Ca++ source to adjust Ca++ on the water?

- How is the procedure (how long should be the settling time, should stir,....?) when I add lime? Should I dilute lime before add (make a solution or add powder)? Alis there a better temperature to do?

Thanks,

Fabiano

I'll let AJ answer to question about converting to mEq/L, as I forget how, but I can answer the other questions.

Yes you should add more Ca++, probably by adding calcium chloride. Calcium sulfate is another option.

Yes you should separate the precipitate from the water. I use an autosiphon.

You may want to add more calcium to the water you separated from the precipitate. It depends on how much is left over (which depends on how much additional calcium you added initially and how much caco3 fell out of solution).

I usually add all my extra calcium and the lime to an empty pot. Then I add the water a gallon (3.78 liters) at a time, stirring a little after each gallon, until I reach my full volume. I do this at room temperature, but I imagine warmer might be better because caco3 is less soluble at higher temps (This is why you can boil water to decarbonate (remove caco3).). After I hit full volume I let the water sit for about 12 hours. It should already be cloudy at this point...that's the caco3 coming out of solution.

 

[ajdelange]

- How change mg/L to mEq/L?

Your alkalinity is expressed in ppm as CaCO3. To convert to mEq/L divide by 50. You calcium content is expressed in mg/L of the ion. To convert to mEq/K divide by 20.

- After remove the alkalinity, some Ca++ will be consumed to precipitate as CaCO3,

Yes

- Should I remove this precipitate to use this water on mash tun?

Yes, you must separate the clear water from the precipitate and use the clear water. If any of the precipitate gets into the mash it will act like chalk (it is chalk) and raise the pH of the mash. You removed it from the water because you do not want the pH raising effect. If you put it back into the mash you have wasted your time and effort.

- Should I add more Ca++ source to adjust Ca++ on the water?

Yes. You can use the numbers I posted in order to estimate what the calcium level will be after decarbonation by this method and then add additional calcium so that the calcium level will be what you want for your beer. If you do this do it before lime treatment as extra calcium before lime addition will allow you to remove more bicarbonate.

How is the procedure (how long should be the settling time, should stir,....?) when I add lime? Should I dilute lime before add (make a solution or add powder)? Alis there a better temperature to do?

Here's the procedure as I laid it out for an article in an old brewing magazine. The whole article is at http://wetnewf.org/pdfs/Brewing_articles/BT_Alkalinity_II/AlkalinityPtII.pdf and this part starts on p14:

1. Add 1 tsp. of chalk for each 5 gallons of water to be treated to the water.
2. Multiply the temporary hardness of the water by 0.74 to get a rough idea of the amount of lime required (in mg) to treat 1 L. Then multiply by the number of liters to be treated and divide by 1000 to get the number of grams required for the entire volume.
3.Increase the result from Step 2 by 20-30% and place this in a small beaker or flask. Add enough water to get this into suspension.
4. Add the slurry from Step 3 to the water in initially large and then smaller increments. Stir thoroughly and check pH after each addition.
5. Continue additions fairly rapidly until a pH between 9.5 and 10 is reached.
6. Monitor pH. As precipitation takes place the pH will fall back (see Figure 3.1)
7. At this point add only small amounts of additional slurry to maintain the pH in the 9.5 - 10 region.
8. pH will continue to drop as CO2 from the air is dissolved but the rate of drop will slow. When it does, stop addition of lime and let the water sit while the precipitate settles.
9. Decant the water from the precipitate and measure hardness and alkalinity.

[/QUOTE]

 

[Borisfa]

Thanks @afr0byte and @ajdelange. More some questions:

My Water report is:

- Alkalinity: 186,5 mg CaCo3/L
- Bicarbonate: 225,1 mg/L
- Carbonate: 1,2 mg/L
- Calcium: 63,6 mg/L
- Magnesium: 3,4 mg/L
- Total Sulfate: 0
- Nitrite: 0
- Nitrate: 0,24 mgN/L
- Sodium: 4,8 mg/L
- Iron: 0
- Total Hardness: 172,9 mg/L
- pH: 7,5

My alkalinity: 186,5 mg/L or 3,73 mEq/L.
My Calcium : 63,6 mg/L or 3,18 mEq/L.

1) For a maximum alkalinity removal, Should I add about 0,55 mEq/L ou 11 ppm of some Calcium source (I need, at least, 74,6 ppm of Calcium)?

2) Considering I adjust my water to 74,6+30% = 97 mg/L of Calcium to remove Alkalinity and considering I need more Calcium for my mash (about needed 80 mg/L for mash) of Calcium on my mash, so I need add more 80 mg/L. Resuming, Will I need a initial Calcium content of 177 mg/L (97 ppm for decarbonating +80 ppm for mash) . Is this right?

3) Now about Lime, considering that is right remove 3,73 mEq/L of alkalinity, so I am need about 1,9 mmol/L of Lime, that represent 38 mg/L or 76 mg/L?

Thanks again,

Fabiano da Mata

 

[Borisfa]

@ajdelange, we add chalk to shift reaction to right side?

 

[Borisfa]

Here's the procedure as I laid it out for an article in an old brewing magazine. The whole article is at http://wetnewf.org/pdfs/Brewing_articles/BT_Alkalinity_II/AlkalinityPtII.pdf and this part starts on p14:

@ajdelange, on the article, you said the "As the molecular weight of slaked lime is 74.09 each gram is 135 mM and will treat 27 mEq of bicarbonate or 1350 mg as CaCO3" I think that the right would be "....each gram is 13.5 mM..." and how we have 1 mmol of Lime for 2 mmol of CaCO3, I think that the right would be "... each gram is 13.5 mM and will treat 27 mEq (1648 mg) of bicarbonate or 2700 mg (2 mmol) as CaCO3" because the MW balance we have:

- 122/74 (2HCO3-/1Ca(OH)2) = 1648,6 mg.
- 200/74 (2CaCO3/1Ca(OH)2) = 2702,7 mg.

Are these wrong?

Thanks,

Fabiano

 

[ajdelange]

There is a theoretical limit as to how much calcium and carbonate can simultaneously be in solution: [Ca++][CO3--] < Ks
expresses it mathematically. The reaction with lime is

Ca++ + 2HCO3- + (Ca++ + 2(OH)-) ----> 2CaCO3 + 2H2O

The extent to which this reaction takes place depends on how much reacts to get [Ca++][CO3--] > Ks. Adding calcium in any form pushes the reaction to the right. Adding OH- pushes the reaction to the right. Clearly, then, to maximize the amount of bicarbonate precipitated you should increase the amount of lime and the amount of calcium. If, however, there is excess lime it won't react and lime, being alkaline, will contribute to the alkalinity of the water and your efforts will have been in vain. Thus is why we try to guess what the correct amount of lime to add may be based on the stoichimetry implied by the equation. However, it doesn't tell the whole story. It is possible to have supersaturated solutions of CaCO3, that is, solutions where [Ca++][CO3--] > Ks and precipitation does not occur or does not occur to the point where [Ca++][CO3--] =< Ks. This is why the procedure recommends adding calcium carbonate to the mix before treatment. It is hoped that the crystals will serve as precipitation nuclei and insure that the maximum amount of precipitation forms. This is why DeClerck recommends experiments with different amounts of lime and choice of the dose which gives the best decarbonation. This is why the procedure requires the use of a pH meter for best results. This is why the procedure recommends that hardness and alkalinity be measured for each trial dose (how else would you know which is the most effective).

In general, if you want to get more bicarbonate out you add more calcium in the form of a non alkaline salt such as the sulfate or chloride. Increasing [Ca++] decreased the amount of [CO3--] required to reach [Ca++][CO3--] = Ks. Thus, if you plan to augment calcium, do it before lime treatment.

It is much easier to just boil your water. You should be able to decarbonate it equally effectively and you don't have to worry about correctly adjusting the lime dose. Again, adding supplemental calcium before boiling is a good idea as is an addition of chalk for nucleation.

 

[Borisfa]

@ajdelange, look for these messeges above that were quote below.

My Water report is:

- Alkalinity: 186,5 mg CaCo3/L
- Bicarbonate: 225,1 mg/L
- Carbonate: 1,2 mg/L
- Calcium: 63,6 mg/L
- Magnesium: 3,4 mg/L
- Total Sulfate: 0
- Nitrite: 0
- Nitrate: 0,24 mgN/L
- Sodium: 4,8 mg/L
- Iron: 0
- Total Hardness: 172,9 mg/L
- pH: 7,5

My alkalinity: 186,5 mg/L or 3,73 mEq/L.
My Calcium : 63,6 mg/L or 3,18 mEq/L.

1) For a maximum alkalinity removal, Should I add about 0,55 mEq/L ou 11 ppm of some Calcium source (I need, at least, 74,6 ppm of Calcium)?

2) Considering I adjust my water to 74,6+30% = 97 mg/L of Calcium to remove Alkalinity and considering I need more Calcium for my mash (about needed 80 mg/L for mash) of Calcium on my mash, so I need add more 80 mg/L. Resuming, Will I need a initial Calcium content of 177 mg/L (97 ppm for decarbonating +80 ppm for mash) . Is this right?

3) Now about Lime, considering that is right remove 3,73 mEq/L of alkalinity, so I am need about 1,9 mmol/L of Lime, that represent 38 mg/L or 76 mg/L?

What would be right? on calcs above?

@ajdelange, on the article, you said the "As the molecular weight of slaked lime is 74.09 each gram is 135 mM and will treat 27 mEq of bicarbonate or 1350 mg as CaCO3" I think that the right would be "....each gram is 13.5 mM..." and how we have 1 mmol of Lime for 2 mmol of CaCO3, I think that the right would be "... each gram is 13.5 mM and will treat 27 mEq (1648 mg) of bicarbonate or 2700 mg (2 mmol) as CaCO3" because the MW balance we have:

- 122/74 (2HCO3-/1Ca(OH)2) = 1648,6 mg.
- 200/74 (2CaCO3/1Ca(OH)2) = 2702,7 mg.

Are these wrong?

Are these wrong?

Sorry for reply, but how I sent multiples messeges, some of that could miss.

Thanks again,

Fabiano da Mata

 

[ajdelange]

@ajdelange, on the article, you said the "As the molecular weight of slaked lime is 74.09 each gram is 135 mM and will treat 27 mEq of bicarbonate or 1350 mg as CaCO3" I think that the right would be "....each gram is 13.5 mM..."

I do too! 1000/74.09 =13.49. That's been out there for years and no one ever noticed the mistake before. Guess no one ever read it or maybe it's obvious that I left out the decimal point.

..and how we have 1 mmol of Lime for 2 mmol of CaCO3, I think that the right would be "... each gram is 13.5 mM and will treat 27 mEq (1648 mg) of bicarbonate or 2700 mg (2 mmol) as CaCO3" because the MW balance we have:

It's 1 mmol of Ca(OH)2 treats two mEq of bicarbonate. A mEq of bicarbonate (alkalinity) is approximately 50 ppm as CaCO3 thus 27*100 = 2700 mg as CaCO3.

 

[Borisfa]

Multiple postage. Sorry.

 

[Borisfa]

Multiple postage. Sorry.

 

[Borisfa]

Thanks @afr0byte and @ajdelange. More some questions:

My Water report is:

- Alkalinity: 186,5 mg CaCo3/L
- Bicarbonate: 225,1 mg/L
- Carbonate: 1,2 mg/L
- Calcium: 63,6 mg/L
- Magnesium: 3,4 mg/L
- Total Sulfate: 0
- Nitrite: 0
- Nitrate: 0,24 mgN/L
- Sodium: 4,8 mg/L
- Iron: 0
- Total Hardness: 172,9 mg/L
- pH: 7,5

My alkalinity: 186,5 mg/L or 3,73 mEq/L.
My Calcium : 63,6 mg/L or 3,18 mEq/L.

1) For a maximum alkalinity removal, Should I add about 0,55 mEq/L ou 11 ppm of some Calcium source (I need, at least, 74,6 ppm of Calcium)?

2) Considering I adjust my water to 74,6+30% = 97 mg/L of Calcium to remove Alkalinity and considering I need more Calcium for my mash (about needed 80 mg/L for mash) of Calcium on my mash, so I need add more 80 mg/L. Resuming, Will I need a initial Calcium content of 177 mg/L (97 ppm for decarbonating +80 ppm for mash) . Is this right?

3) Now about Lime, considering that is right remove 3,73 mEq/L of alkalinity, so I am need about 1,9 mmol/L of Lime, that represent 38 mg/L or 76 mg/L?

Thanks again,

Fabiano da Mata

@ajdelange, and about my calcs, what can you say?

About #3, revisiting my calcs, I have a doubt:

3.1) Would be 1,9 mmol * 74 mg/mmol = 141 mg/L of Lime

or

3.2) Would be 186,5 mg of Alkalinity/L * (74 mg of Lime/mmol) / (200 mg of Chalk/mmol) = 69 mg/L

Ca++ + Ca(OH)2 + 2 HCO3- --> 2 CaCO3 + 2 H2O
MW 40 74 122 200 36
Base y x 186,5

y = 186,5*40/200 = 37,3 mg/L
x = 186,5*74/200 = 69,0 mg/L

But On x we have 37,3 mg/L of Ca++ with the same 37,3 mg/L of Ca++ ion = 74,6 mg/L would be the stocheometric ratio. With 30% recommended on article, 97,0 mg/L of Ca++

For the same reason, stocheometric ratio for Lime indicate 69 mg/L.

What is the right, 3.1 or 3.2?

Thanks a lot for your help.

Fabiano da Mata

 

[ajdelange]

Unfortunately, there is no 'right' answer. If you follow the guidelines of the article (with the missing decimal point inserted) looking at the water as is i.e. with its 3,73 mEq/L alkalinity and 3,18 mEq/L calcium hardness you will estimate the lime needed from the temporary hardness which is 3,18 mEq (all the calcium hardness as there is more alkalinity than hardness). The article implies that the reaction

Ca++ + 2HCO3- + (Ca++ + 2(OH)-) ---> 2CaCO3 + 2H2O

goes to completion and as it requires 1 mmol of lime for each 2 mEq of temporary hardness seems to indicate that we would need 3,18/2 = 1,59 mmol of lime (1,59*74.1 = 117.8 grams). The article suggests preparing a slurry of 20% more than that making a total of 141.4 grams for each liter of water to be treated. This slurry is then added incrementally to the water while pH is monitored. All the slurry will not be used. We know that if a decarbonation plant is well operated that we can expect a reduction in the temporary hardness down to about 1 mEq indicating that there will be quite a bit of excess. But we in fact never know exactly what will happen.

We also know in this case that the temporary hardness, and therefore, the amount of alkalinity that can be removed, is limited by the calcium. If we'd like to get more of the alkalinity the answer is to simply increase the calcium making the alkalinity the limiting factor. Any addition of calcium which brings its total to greater than the alkalinity will achieve this. Increasing calcium to >3,73 makes 3,73 mEq/L the temporary hardness and so we calculate that we need 1/2 of 3,73 mEq or 1,86 mmol of Ca(OH)2 the amount we would augment by 20% and prepare as a slurry. But again we don't know exactly what will happen and that is why we use pH meters to control the addition and measure the results. As I said earlier, for a home brewer the boiling process is equally as effective and much simpler to manage. A commercial brewer would not choose boiling as the cost of the lime is much less than the cost of the energy and he has a lab to verify that he is doing the lime treatment optimally.

The other approach is to look at the temporary hardness of 3,18, guess that you are going to reduce that to 1 and calculate the amount of lime based on the 2,18 reduction. You are really flying blind here but I guess this is what a lot of home brewers do.

 

[Borisfa]

People, may I add all salts on mash water and not add any salt on sparge water (only adjust pH of sparge water)? What is the potencial benefit (or not) to add all salt only on mash water?

Thanks,

Fabiano da Mata

 

[Homercidal]

Salts added to the mash are to put your pH into the proper range, and the sparge salts are added to contribute more flavor ions, as I understand it. They also help place the finished beer in the proper pH range, although I think I've heard that the beer naturally corrects itself to a certain degree, if possible.

 

[Borisfa]

People, EZ water and Bru'n Water spreadsheet help us to calculate how many salts we should add to adjust our water.

So, some salts have H2O on their formation.

My doubt is: should I adjust the salt mass to considere that water? Because I suspect that mass is to pure component (CaSO4, MgSO4, CaCl2....) and when I measure, for example 3 g of CaSO4 this mass is not CaSO4, but CaSO4.xH2O.

 

[Borisfa]

Make sense my doubt? Or epsom, gympsum, CaCl2 labeled on spreadsheats already considere hydrate (water)?

 

[Yooper]

Make sense my doubt? Or epsom, gympsum, CaCl2 labeled on spreadsheats already considere hydrate (water)?

No. The only one that you have to consider is Calcium Chloride (CaCl2) since it will easily absorb water. The answer is to use fresh CaCl2 and keep it tightly closed in a small container and use it quickly.

 

[ajdelange]

Make sense my doubt? Or epsom, gympsum, CaCl2 labeled on spreadsheats already considere hydrate (water)?

Water of hydration must be taken into account. Gypsum and epsom salts are pretty stable in this regard and the spreadsheets usually automatically account for the water by assuming 7 for epsom salts and 2 for gypsum. Calcium chloride is trickier. See https://www.homebrewtalk.com/showthread.php?t=501377 for how to manage it.

 

[z-bob]

This is the best thread I've seen on this topic, so I'll necro it to ask a related question.

Slaked lime absorbs CO2 out of the air and slowly converts to carbonate. Does this need to be taken into account when calculating the amount of lime to add?

Let's say I have a 5 year old bag of Mrs Wage's' Pickling Lime that I bought for making pickles. It's been stored in the original (opened) paper bag in a dry place. How much is still lime and how much is chalk?