August 22, 2010

My new pH tester!


Gosh, it's been an embarrassingly long time since I've posted here.  I've been quite busy over at Eating Rules, and I'm thrilled to be back in the kitchen making cheese once again.

A few months ago, my favorite pickler bought me a Hanna Waterproof pH Tester for my birthday, and today we're finally giving it a whirl.

This thing is awesome Dip it in the milk or whey, and about 10 seconds later, Blammo! you've got a pH reading!  (okay, there isn't actually any explosion, unless you yell "Blammo!" yourself, which I highly recommend).

It's as easy as using a thermometer (and actually includes a thermometer, since pH readings done in this manner must be temperature-calibrated).

Of course, without knowing exactly what pH we're supposed to hit and when, this cool little device won't actually be much help.  None of my recipe books reference pH numbers -- just times and temperatures.

I've been sifting through my copy of Paul Kindstedt's American Farmstead Cheese, which is by far the most technical book in my library.  He discusses pH in depth -- but since the book doesn't include any specific recipes, that only helps so much.

I did find a table on page 155 where he indicates "optimum" pH -- with some timing -- for making Cheddar.  Already it's been a bit of a help:  Heating the curds (bringing them up from 86°F to 100°F) went slower than I would have liked, but keeping an eye on the pH still let me know we were making progress.

As the pH slowly worked its way down, I decided to drain the curds at 6.15 -- based on Kindstedt's table.  This took more than an hour longer than Ricki's recipe, but less time than indicated in the table.

As I write this, the curds are cheddaring comfortably in the pot.  After only 15 minutes, on the first flip, the pH was down to 5.80.  If all goes according to plan, at the end of the requisite two hours we'll be at exactly 5.35, and then we'll mill the curds (translation: break them into small cubes), and proceed with the next steps.

If we hit 5.35 a little early, I might actually decide to stop cooking and mill them sooner than Ricki calls for.

I'm excited to start using the pH tester every time -- building my own reference library -- and hopefully with a bit of diligence I'll be able to solve my texture problems once and for all.

Do you have any experience pH readings?  Please post in the comments with any questions and/or advice!

5 comments:

  1. More cheese, much more cheese! Welcome back. I would strongly suggest you remove a small sample from your pot to test the pH. After testing, discard the sample. Your electrode likely sits in a storage solution and you probably don't want any of that in your cheese. Its not uncommon for mold and other funky stuff to sit in your storage solution too. Even with rinsing your electrode before taking each reading (which I'm sure you do), you may risk some contamination.
    Does pH only affect process timing in cheese making? If pH adjustments are necessary, there's food safe adjustments you can make during your procedure. Understanding pH and how to adjust it can lead to lots of potential (pun intended!).

    ReplyDelete
  2. Good advice. I was rinsing the tester between samplings - but yes, for most of the process I could certainly pull out some whey and then discard after testing.

    I haven't figured out how to test the curd once it's stopped expelling (most of) the whey. Ideally it would be good to know the pH of the cheese as it goes into (and comes out of) the press -- but with my current tester I can't think of a way to do that (since it can only test liquids).

    As for adjusting, I'm not yet sure what adjustments can be made. I think adding Calcium Chloride at the time of renneting is one strategy -- and I think that is often done based on the seasonal changes of the milk (so it would be on the *next* batch that you adjust). For the current batch, the only thing I can think of is to increase or decrease some of the time between steps.

    ReplyDelete
  3. Knowing the PH of the Whey gives you a very close idea of the PH of the Curd.
    The PH of the Cheddar curd may easely go down to PH 5. The Cheddar has a slightly more sour taste than most other cheeses

    ReplyDelete
  4. Hi there,

    I am a cheesemaker down in Little Rock Arkansas. Enjoying the blog! But I would caution against these types of readers. while they work great for beer and wine, the calcium in the milk tends to gum up the readers.

    They end up giving false readings after even just 5 uses! I know a few cheesemakers that have regretted buying these.

    pH Strips work very well and you can also use them to test curd directly by cutting a slice in the curd and placing the end of the strip into the curd for a bit.

    Good luck with your cheesemaking!

    ReplyDelete
    Replies
    1. B"H

      Which ph strips are you using? Most ph strips are very levels. They change colors at a full number variable.

      Thanks,
      Joseph

      Delete