Viable calcium chloride

[Lloyd]

I'm struggling with curds shattering, which is making me wonder if my CaCl is viable. I've just measured it's pH, and it's is 9.84, which seems to be outside the expected range (according to Wikipedia). Is this a problem? Can anyone tell me the pH of their 33% solution?

Thanks

[Lloyd]

My other observation, note I have decanted some of the solution, is that it is clear with a fine sediment. Shaking disperses the sediment, to give a cloudy solution. I'm presuming this is a saturated solution.

[Lenomnom]

If it's a saturated solution then warming it should cause the sediment to dissolve. Mind you about anything would be likely to dissolve on heating, but if it doesn't then I think you have something other than CaCl2 in there.

[Lloyd]

So at 20 degrees C, I think a saturated solution is around 42%. (74.5g per 100ml, that is 74.5g in a total solution of 174.5g.)

My solution, which is labelled as 33%, is now at about 18C, and there is still a very fine sediment.  Its should not be a saturated solution, so why is there some sediment? When I shake it, it does have a chalky, cloudy appearance.

[Lenomnom]

So at 20 degrees C, I think a saturated solution is around 42%. (74.5g per 100ml, that is 74.5g in a total solution of 174.5g.)

My solution, which is labelled as 33%, is now at about 18C, and there is still a very fine sediment.  Its should not be a saturated solution, so why is there some sediment? When I shake it, it does have a chalky, cloudy appearance.

One thing I think it isn't is calcium carbonate. One might think the carbonate could form from exposure to atmospheric CO2, but if you look at the reactions;

CO2 + H2O -> H2CO3

CaCl2 + H2CO3 -> CaCO3 + 2 HCl

That last reaction really really prefers to run backwards so the carbonate forms only very rarely and the second it appears it is annihilated by the HCl.

So I think at least it isn't chalk.

Can u check the pH?

[Lloyd]

pH 9.84 (see first post).  I thought that was too high, but I have read an article today (one of many) that suggests 9 is not unreasonable.

[Lenomnom]

pH 9.84 (see first post).  I thought that was too high, but I have read an article today (one of many) that suggests 9 is not unreasonable.

I find this baffling. Why would an ordinary chloride salt solution be anything but neutral? I know odd things can happen with multiply charged ions in high concentrations, but geez...

[Lloyd]

I know my probe is only calibrated at 4 and 7, but I wouldn't expect it to be that far out. It is certainly a bit strange.

[mikekchar]

pH 9.84 (see first post).  I thought that was too high, but I have read an article today (one of many) that suggests 9 is not unreasonable.

I find this baffling. Why would an ordinary chloride salt solution be anything but neutral? I know odd things can happen with multiply charged ions in high concentrations, but geez...

9.84 seems way out there to me, but I think you need to know the composition of the water to begin with.  Many municipal water supplies use slaked lime to  precipitate out calcium from water (so that you don't get chalk deposits in the pipes).  The result is water that has a very high CO3 (carbonate ion) level, but relatively low Ca (calcium ion) level.  By adding CaCl2, you are raising the Ca level, which in combination with the carbonate level will buffer the water on the basic side (I think...)  Again, I *think* carbonate buffers out about 8.3 but don't quote me on that :-)

[Lenomnom]

pH 9.84 (see first post).  I thought that was too high, but I have read an article today (one of many) that suggests 9 is not unreasonable.

I find this baffling. Why would an ordinary chloride salt solution be anything but neutral? I know odd things can happen with multiply charged ions in high concentrations, but geez...

9.84 seems way out there to me, but I think you need to know the composition of the water to begin with.  Many municipal water supplies use slaked lime to  precipitate out calcium from water (so that you don't get chalk deposits in the pipes).  The result is water that has a very high CO3 (carbonate ion) level, but relatively low Ca (calcium ion) level.  By adding CaCl2, you are raising the Ca level, which in combination with the carbonate level will buffer the water on the basic side (I think...)  Again, I *think* carbonate buffers out about 8.3 but don't quote me on that :-)

Now THAT makes chemical sense. It would give just the right small amount of chalk and account for the odd pH, at least partially.

[Lloyd]

I would have hoped that a purchased, made up solution would use distilled water, and so would not be susceptible to this.

Do you think this would adversely affect the normal action of the CaCl on the curds?

[Lenomnom]

I would have hoped that a purchased, made up solution would use distilled water, and so would not be susceptible to this.

Do you think this would adversely affect the normal action of the CaCl on the curds?

I don't know, but you could run a 1-cup test to see.

[Lloyd]

Sorry, badly phrased question. I'm getting poor quality curds, even with different quantities (various one cup tests). Could this be to blame?

[mikekchar]

I think it is unlikely.  Calcium chloride is just a salt.  There isn't really anything that can go wrong with it.  It's weird about the pH, but I can't find any good references about it.  The problem is more likely your milk.  What temperature pasteurisation is it?

[Lenomnom]

Sorry, badly phrased question. I'm getting poor quality curds, even with different quantities (various one cup tests). Could this be to blame?

Just guessing here but if you varied the amount and there was no effect, then it's probably not the source of the problem. Maybe we can get some people here to pH test their current CaCl2 supply for comparison.

Have you changed your milk source lately? Are your cultures fresh?