The BIG PIZZA SAUCE EXPERIMENT - Measure Acidity & Sweetness

[norma427]

petef,

I can understand what the purpose of your experiment is.

I just took pH numbers on some things that are in my kitchen.  These are the pH numbers.

Number one bottled water                5.59
Number two bottled water                5.88
Tap water                                      6.86

Wildflower honey                             3.96

vinegar one                                     2.77
vinegar two                                     2.73
vinegar three                                   3.15
vinegar four                                     2.68

Just from taking this few numbers, it still makes me wonder how this experiment will work out.  Does anyone here on the forum know how this all can work to see if we can come to conclusions, when using pH numbers for sauce?

I will keep taking pH numbers if you want me to.

Norma

[shuboyje]

I can't believe the brain fart I had not to mention a brix refractometer.  That would be the instrument needed to measure the sugar content, if you search online you can find one for about $35, not sure if this experiment is worth that to you.  I also want to mention measuring titratable acidity again.  It's easy to do and test kits can be had for under $10 that will last many tests.  The titratable acidity can vary greatly at the same pH and will tell you much more then pH alone.    

[petef]

I now have 2 PH litmus test kits, one measures 2.8 thru 4.4 and one measures 4.6 thru 6.2.
Today I measured as follows:

* Cento brand, San Marzano DOP Cert. peeled whole tomatoes... aprox 4.5 PH

* Pizza Sauce below...  aprox 4.5 PH

      28 ounces    Canned Peeled San Marzano DOP Cert. Tomatoes (Cento)
       3 teaspoons Olive Oil (Bertolli Classico)
     1/2 teaspoon  Salt
     1/4 teaspoon  Basil
     1/8 teaspoon  Red Hot Pepper, finely ground
       1 teaspoons Balsamic Vinegar
       1 teaspoons White Vinegar       
       3 teaspoons Wine Vinegar
       3 Teaspoons Honey

My problem now is that my test kits both measure at the end of their range and I can't seem to get an accurate reading from 4.4 to 4.6. That's why I had to estimate it at 4.5 PH. In fact, I'm getting the same PH reading after adding a considerable amount of vinegar that my taste test can clearly detect an increase in acidity. I question the accuracy of my measurements.

For my experiment above, I need to measure in the 4.4 to 4.6 range. What shocks me is the lack of change in PH for adding so much vinegar. I also measured the PH after adding the vinegar and before adding the Honey but I'm still getting the same 4.5 PH reading.

I'm curious to see how other people make out with their PH measurements.

---pete---

[petef]

 I also want to mention measuring titratable acidity again.  It's easy to do and test kits can be had for under $10 that will last many tests.  The titratable acidity can vary greatly at the same pH and will tell you much more then pH alone.    

Thanks, you may be on to something here.  So far, my PH tests don't seem to correlate with my taste tests. See my previous post for details. I'll have to research "titratable acidity".

---pete---

[norma427]

petef,

I used some of Les’s sauce that I unfroze last evening.  I took the pH of Les’s sauce after it was unfrozen.  The pH was 4.22.  I don’t know if this can tell you anything or not.

Norma

[petef]

petef,

I used some of Les’s sauce that I unfroze last evening.  I took the pH of Les’s sauce after it was unfrozen.  The pH was 4.22.  I don’t know if this can tell you anything or not.

Norma

Thanks Norma. At this point it seems that all our PH readings are in the range 4.0 to 4.6. In my experiment, I added enough vinegar to make a huge change in taste what I consider to be "acidic" but I was unable to measure any difference in PH. My measurement technique using litmus test strips may be the problem, I'm just not sure. 

Since you have a meter accurate within 0.1 PH, it would be very helpful if you measured the PH of a sauce recipe before and after adding the vinegar. Then by adding the same amount of sugar or honey and measuring the PH again.

Norma, if you don't like vinegar in your sauce, perhaps you can just work with a small 3 oz sample of canned tomatoes. Cook it down a bit and add just 1/2 ts of vinegar and 1/2 ts of sugar or honey, measuring the PH at each step and tasting as well.

I hope that's not asking too much. Thanks.

---pete---


 

[norma427]

Thanks Norma. At this point it seems that all our PH readings are in the range 4.0 to 4.6. In my experiment, I added enough vinegar to make a huge change in taste what I consider to be "acidic" but I was unable to measure any difference in PH. My measurement technique using litmus test strips may be the problem, I'm just not sure. 

Since you have a meter accurate within 0.1 PH, it would be very helpful if you measured the PH of a sauce recipe before and after adding the vinegar. Then by adding the same amount of sugar or honey and measuring the PH again.

Norma, if you don't like vinegar in your sauce, perhaps you can just work with a small 3 oz sample of canned tomatoes. Cook it down a bit and add just 1/2 ts of vinegar and 1/2 ts of sugar or honey, measuring the PH at each step and tasting as well.

I hope that's not asking too much. Thanks.

---pete---

Pete,

I also agree that the pH readings so far are in the range you posted.  I usually use Stanislaus tomato sauce in making my tomato sauce, but have used other brands of tomatoes.  I don’t cook my sauces for pizzas with the exception of baking tomatoes for Les’s sauce.  The only sauces I cook are sauces for pasta.  I don’t do that too often.  I could take a small amount of my Stanislaus  sauce and add honey or vinegar and taste and test the pH if you want me to.  I just wonder how much vinegar or honey is needed to get the right taste, because each of us have different tastes, when it comes to pizza sauce.

Recently I had talked to a honey producer in my area at market. He gave me a bottle of raw and unprocessed Lancaster county spring blossom honey.  I just took the pH of the honey he gave me and it is 4.64.  He was interesting to talk to and said honey can be unpredictable at times if the weather is too hot or humid.  He has some kind of measuring tool to use to see if the honey does ferment.  Usually honey bees can control the honey before it ferments, but sometimes when the weather is too hot or humid the bees can have problems because of the heat and humidity and the moisture content needs to be around 16-17 % or fermentation can take place.  If that happens the yeast will grow and then the honey wouldn’t be fit for human consumption.  He does buy honey from other sources to make honey, but now his hives are vacationing in Florida.  He also said he keeps his honey in big storage bins and the honey does granulate at some point and then he just reheats it until it is liquid again.

Let me know how you want me to go about the tests without heating the sauce.  Do you think the sauce really needs to be heated?

Norma

[petef]

Let me know how you want me to go about the tests without heating the sauce.  Do you think the sauce really needs to be heated?

When I said to first cook it down a bit, I was just trying to be consistent with my recipe  that used 28 oz of canned tomatoes cooked down about 25% and then adding about 5 ts of vinegar.

For you, just keep it simple. I don't think it will matter all that much whether you heat it.

1.) Measure out 3 ounces of raw canned tomato, mash it up to make a sauce and measure PH.
Taste it too.

2.) Add 1/2 ts of vinegar (white vinegar is fine), mix it well and measure PH. Taste it too.

3.) Add 1/2 ts of Honey, mix it well and measure PH. Taste it too.

The tasting is just a guide to let you know how much different the sauce tastes in acidity and
as a comparison to the PH tests.

You will now have a small amount of sauce to try on some English muffin pizzas or on some sliced Italian bread pizza cooked in the toaster oven. You will also need to add some salt to taste and perhaps some basil too.

I found that pizza sauce that is more on the acidic side does not taste that great alone, but when combined with the cheese & dough and other toppings it's just right. My favorite pizza sauce has that acidic taste that makes you crave a Coke to go along with it. Perhaps that's why so many pizza shops make their sauce more on the acidic side. In any case, that's what I've become accustomed to and it's my target sauce.

---pete---

[norma427]

Pete,

The next time I open a can of sauce I will go by your recommendations on how to test the pH and what to add.

Thanks,

Norma

[DNA Dan]

The problem with sweetness is not just limited to the amount of sugars detected. It's the other factors that are in a sauce which can greatly influence the "perceived" sweetness. For instance a sauce which is heavily seasoned or contains a lot of bitterness, salt, etc. may be percieved as less sweet even though it might have an equivalent amount of sugar as another sauce. Bitter and salty tastes play differently on the tongue and can change one's perspective on the sweetness.

[matermark]

I hate to rain on everyone's sugar measuring parade, but there's not a chance in heck a hydrometer will reliably measure sugar content in tomato sauce.  There's too little sugar and far too much extraneous matter. The only thing a hydrometer will tell you is density- which might actually be good if you feel like a manufacturer might be inconsistent with their puree consistency.

As far as measuring pH in tomatoes... now that I'm interested in seeing. I'm not a big believer in adding acid to sauce, but if the pH numbers revealed high fluctuations from batch to batch, season to season, I might consider standardizing my pH levels with a naturally occurring tomato acid such as citric (or scaling back my added sugar based on pH). 

Here's a chart I put together of some heirloom tomatoes; it was all just results averaged over 1 season and should only be used to roughly see minor differences, as pH as well as Brix can change by weather, location, methods of growing/watering/fertilizing, etc. In other words, these #s can be completely different for someone else! At least the conditions were the same for all the varieties listed on that given testing.

I will try to post pH as well as Brix which is sugars.

Is there a way to post pics? My chart was a screen capture taken many years ago as a jpg (pic) but I can convert it to gif or bmp if necessary.

OK, I'm above size limits... hang on... there! jpg to gif to MS Paint to divide in half to fit under size limits... if this works I'll do Brix too.

[matermark]

Here are the Brix #s; I don't see stickies so copy them, they are all pics! Hope this helps!