Figure One

Science. Communication. Community.

Science Con Queso

Pi day hangover? I will rationally not be discussing that irrational number. But you know what’s great for a hangover? PIzza PIe?  And what is on pizza? Cheese. Glorious, glorious cheese.

by Kerstin Nordstrom

via Wikimedia commons

via Wikimedia commons

I enjoy fixing, designing, and making things. This translates well into a career as a professional tinkerer, though some might use the fancy word ‘scientist.’ I have also always been obsessed with food. Combine those two interests, and you’ll often find me tinkering in the kitchen. I sometimes feel self-conscious of this because of all of the bandwagon hipster-ism and Pinterest-ism surrounding food currently, but I’m mostly over it. After all, I do enjoy wearing plaid shirts and using social media. Call me a hipster, as you will.

I had a realization recently, and that was that I had never made cheese. I love cheese. Actually, I had never made any fermented foods. I love fermented foods! Give me some salami and a beer any day over chocolate and ice cream. I ordered a cheesemaking kit to get me going.

I get veggies delivered to my house from a local-ish farm. A recent delivery included a head of cabbage. Usually when we receive cabbage, I shrug and give it to my roommate, in exchange for a few extra mushrooms. This time, fermentation epiphany still in mind, I decided I was going to make sauerkraut. I love sauerkraut.

The sauerkraut is simple. Shred it and muddle with salt. The salt will suck up the water released by crushing the cell walls in the cabbage. Throw it in a jar, making sure the liquid covers the shreds. Let it sit until it sours, a couple of weeks.

Do your worst, anaerobes.

Do your worst, anaerobes.

That same day, in a fit of inspiration, I decided to crack open the cheesemaking kit. It included a strainer, cheesecloth, calcium chloride, rennet tablets, bacteria, and a thermometer. Lots of moving parts. I decided to go with the simplest cheese, a cottage cheese. Mix calcium chloride into milk, bring the milk up to temperature, then add the bacteria and rennet. Let it hang out for 8 hours to sour and curdle. After this, you should have curds. Heat it up again to shrink the curds, then drain off the whey.

The remarkable thing is that both things are using the same process. In sauerkraut, ambient bacteria in the air are in the watery mix, specifically Lactobacillus. Lactobacillus is anaerobic, meaning it doesn’t need exposure to oxygen to thrive. The bacteria break down naturally present sugars in the cabbage into the sour tasting lactic acid. It just takes a long time at room temperature.

Cheese is the same basic chemistry, but we put the process in overdrive. We add lactobacillus to the milk, so we have a lot of extra workers converting sugar to acid. We also crank up the temperature, which makes the encounters between bacteria and sugar more common, and so the souring reaction occurs more frequently.

And that’s really it. You can make cheese in this way, if you’re willing to wait longer on the back end: the curdling. The back end is the real difference between sauerkraut and cheese. With cheese, we don’t just want something sour; we want a solid to emerge from a liquid.

Casein, the main protein in milk, is hydrophobic, so it likes to hang out as a little phalanx of casein molecules when it’s in the watery milk. When you make cheese, the acid environment makes the molecules like water even less, so little phalanxes start to coagulate with each other. There are actually four breeds of casein molecules, and rennet aids the coagulation process by disabling one of the kinds of casein molecules that tries its best to prevent coagulation.

So, with rennet you get a harder, better, faster, stronger (thanks, Kanye) protein network (a gel, for those interested), and thus a firmer curd.

My cheesemaking attempt was successful, but the final product has more of the consistency of a ricotta than the familiar chewy chunks of cottage cheese. I’ve realized now that my milk selection was all wrong; I went for the full fat stuff. But when making cheese, especially fresh cheese like cottage cheese, the protein network is really the star of the show. Anything else can get in the way of a consistent outcome, especially when just tinkering around in your kitchen. In fact, many full fat versions you’d buy at the store are just low fat milk versions mixed with some cream.

Signing off, I have to go check on my sauerkraut.

Can't wait for the next round of experiments!

Can’t wait for the next round of experiments!


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s


This entry was posted on March 15, 2013 by in Uncategorized.
%d bloggers like this: