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We are working on a mozz and going by the ph guide, The milk at the point where we are working to get it ripened is measuring 5.62 on the hannah ph meter.
It seemed kind of low so I got a sample fresh from the goat and it is reading 5.7.
Possible bad meter?
Any help would be appreciated.

Robert

I would guess a bad meter. Normal fresh milk should be 6.5 -6.7. Have you used it much before? Has it been calibrated with a known solution? You might check the ph of something you know and see what you get. If it is not working, you will have to learn the "old ways" of telling when it is at a certain point like the curling iron test or just follow the clock and hope for the best. Good luck. I've been there before. Very frustrating. 

Fresh goat milk is 6.4-6.6. Likely bad meter or needs calibration or cleaning.

I calibrated it several months ago using 7 and 4. 
I have used this before but never felt confident in it.
I was out and wanted to recalibrate so spot checked it against distilled water and adjusted.

I will get some more solution and check.

What is the recommended frequency to calibrate pH pens?  Daily, weekly?

Before every make. I keep a master bottle and some small bottles. I pour off a little into small bottles for each batch, calibrate, and then discard.

QuoteFresh goat milk is 6.4-6.6

Linux, Was I right for cows milk? and if so, what is the reason for the ph difference between cows and goats? Any ideas? Just curious.


By the way, coffee joe, I also calibrate every make.

Absolutely, JD. It's just how goat's milk tends to be. I can measure 5 minutes from the udder and it'll be 6.5, where a cow's milk will be 6.65. There are also slight breed differences, but overall goat's milk is just a touch lower.

Put the probe in some vinegar and unless vinegar is 1.13 it is off.
I had to guess on the cheese which resulted in an inadequate stretch (still tasted good with tomatoes).
I will pick up a new bulb and some more buffer solution.
Thanks for the help.

Don't let the probe tip dry out either.  Needs to be kept wet from all that I have read on them.

Quote from: rlatta on July 26, 2010, 12:50:43 PM
Put the probe in some vinegar and unless vinegar is 1.13 it is off.
I had to guess on the cheese which resulted in an inadequate stretch (still tasted good with tomatoes).
I will pick up a new bulb and some more buffer solution.
Thanks for the help.

5% vinegar (.8 M acetic acid) has a theoretical pH of 2.43 at 20-25 C.

Your probe has a bias to read too low. judging from that logarithmic drift, the initial pH of that goat's milk was ~6.5

Yes, I got some small buffer solution packs from the homebrew store and that is correct.
I have to recalibrate several times during a make while I wait for a new probe.
Storing it dry likely damaged it.
I now have 8oz bottles of buffer and storage solution coming (in the meantime, what is the best way to store it -- in one of the buffers?).

Thanks for your help.

Quote from: rlatta on July 29, 2010, 08:23:26 PM
Yes, I got some small buffer solution packs from the homebrew store and that is correct.
I have to recalibrate several times during a make while I wait for a new probe.
Storing it dry likely damaged it.
I now have 8oz bottles of buffer and storage solution coming (in the meantime, what is the best way to store it -- in one of the buffers?).

Thanks for your help.

In neutral 7 buffer or saturated KCl solution. Also, if the probe is good quality it can usually be reconditioned, even when stored dry. The henna handhelds are hit and miss. Their standalone BNCs are better.