Mozzarella, Take 1

I’d successfully engineered some ricotta, the easiest kind of cheese to make at home.  According to the  all-knowing internet, the next step up for would-be home cheese-makers is mozzarella.  A bit more  complicated, but still nothing like making hard cheeses.

Rewind.  Let's hear that again.

A bit more complicated.  Put the stress on complicated.

I strong-armed my friend Clair into joining me for the project.  Actually, she was very easily convinced to join the endeavor, but may never be so again.

You see, mozzarella making is—yes—complicated. 

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We began the project working off this recipe from Gourmet magazine.  I’d prepped by buying citric acid (pure—not the mix of citric and ascorbic acid you can by for canning), rennet (the enzyme that causes the thickening, and which took visits to a couple stores to find), and non-ultra-pasteurized whole milk.  The equipment required included a large stock pot, instant thermometer, cheesecloth, and a method of keeping the milk at a somewhat constant temperature (we went for the water bath in the sink).  The only instant thermometer that I had (after realizing that the candy thermometer didn’t go to a low enough temperature), was a medical thermometer that only read between temperatures of 88.6 degrees Fahrenheit and around 110 (?).

For the first step, we were supposed to bring the gallon of milk to 88-91 degrees and keep it there for about an hour.  Such a task required careful monitoring, occasional dips in the water bath, and fretting over whether the milk was too cold when our substitute thermometer merely read “low” (= below 88.6).  Overall it was easier than I expected, and pretty successful.  The milk hit 92 degrees very briefly twice the entire time, and otherwise hovered around 89-90.

However, the milk never developed firm enough curds.  After doing a bit more research, we have a few different hypothesis for the failure.

• The rennet was the wrong brand.  I unknowingly bought Junket rennet at the store, as it was the only kind that they carried.  As it turns out, Junket rennet is a fairly weak type, useful for custards and ice creams but not so much for cheese.  Many claim that it works fine with mozzarella, but I should’ve been suspicious when the recipe on the Junket box required twice as much rennet as the Gourmet recipe.  We wound up adding more to compensate for the brand, and eventually the milk thickened a little bit, but not nearly enough to make mozzarella. 
• The rennet was too old.  Apparently rennet only lasts 6-12 months, depending on the type (vegetable vs. animal).  I’m not sure what type Junket is, but I think I bought it last summer, and I know I didn’t store it in the refrigerator or freezer (which is ideal).  So it probably lost some potency.
• The rennet enzyme-action was destroyed by dissolving it in chlorinated water.  Before mixing the rennet in the milk, it must be dissolved in a bit of water.  We used tap water, but I later read that sometimes the chlorine in such water is damaging to the recipe.
• The milk I bought was pasteurized at too high a temperature, destroying the milk’s curd-making capacity.  This last hypothesis is a bit less likely.  I was careful to not buy ultra-high pasteurized milk (usually organic), and to get a regional grocery store brand (Martin’s) as national milk brands tend to be pasteurized at higher-than-average but not ultra-high temperatures.  This is also unlikely given that the milk did thicken a little bit, but one never really knows about any brand until successful mozzarella has been created from it.

We will try again in the near future, using fresh, animal-based rennet (supplied by Amazon.com, perhaps?), non-chlorinated water, the same brand of milk (I really doubt that that was the problem), and possibly the mozzarella recipe from America’s Test Kitchen.  After all, it took the author of our recipe eight times to reach success (though he tried to distill all the knowledge he gleaned from the attempts for us readers).

Our cheese wound up with a somewhat ricotta-like texture in the end, and I was able to use some on a home-made pizza fairly successfully.  Not all was lost!

Regulating the temperature of the milk.

Curds separating from the whey.

Chicken pesto pizza, supplemented with store-bought cheese.