Finding Out How To Make Sour Cream. Protip: You Can't.

This is not going to be pretty.

How can a financial empire be built on sour cream?  To find out, I tried making my own.

Sour cream is a fermented product, like beer, wine, cheese and yogurt.  A bacteria (or fungus) is introduced into a fresh product that eats the sugar and converts it into alcohol or acid.  That bears repeating:  Perfectly good milk is contaminated with little tiny bugs that poop acid.

If that sounds disgusting and dangerous, it is.  There are only a very, very few types of microorganisms that produce the exact reactions we want.  There are many, many that just make toxins that will sicken us, if we're even able to eat the food without spitting it out.  If the wrong bacteria reproduce faster than the right ones, your food is ruined.

Then how was sour cream, or wine, invented?  There are some places in the world where the air and/or the vessels we kept liquids in had exactly the right levels of exactly the right contaminants to make something that looked safe enough for somebody to taste and declare good.  From that point, the product could be used as a starter to inoculate larger batches.  And it never dies.  Seriously, there are people claiming to be using starter cultures that date back to before the Civil War.

Sour cream is made the same way as cheese, yogurt and vinegar.  Take perfectly good cream, let it sit out for two days and eat it.

Yum!

Okay, it's a little more complicated than that.  You need just the right mix of lactic acid bacteria.  (Thanks Wikipedia!)  Assuming that, follow any of these recipes.  They're basically the same.  Combine a cup of cream with a tablespoon of buttermilk.  Cover with something like cheesecloth (to let air in while keeping spiders out).  Leave out for 24-48 hours at around 75 degrees until the cream thickens.  Then refrigerate for up to a week.

Even so, you're going to notice that your sour cream, while it tastes a lot like pride, isn't exactly the same as store-bought.  There are a couple reasons.  Your mix of bacteria won't be the same as the proprietary mix used by the large manufacturers.  Yours will probably be thinner, as many sour creams add thickeners like gelatin, guar gum, and carrageen (Breakstone's uses agar).  Yours will also be far more likely to cause you to die.

Why?

Louis Pasteur.

Jerk.

Pasteur realized that the growth of fungi and bacteria in food was somewhat dangerous to ... everybody.  He developed the concept of heating food to kill the native bacteria.  Immediately cooled and sealed off from air, milk and wine could survive far longer without spoiling.  That meant they could be produced in factories and shipped to cities.  They could be kept longer in stores and in homes.  Instead of a week, milk could last a month.

Pasteurization was so successful at reducing illness that it quickly became the norm.  Producers were able to keep milk cows in increasingly worse conditions without worrying that the milk would carry any of the filth found on the milking floor.  (Warning: Don't click if you like milk.)

What does this mean for your sour cream project?  It means it will fail.  Pasteurized cream cannot turn into sour cream.  Most all of the good lactic acid bacteria have been killed.  Those left can't compete with the bad microbes.  You have to use fresh, unpasteurized milk.

But you can't.  It's very hard to find raw milk.  Even when you do, you're exposing yourself to a product that may have any number of risks that we took care of over a hundred years ago.  Without a doubt, some raw milk comes from dedicated and humane dairy farmers.  But some doesn't.  Also, raw milk advocates are a little ... um ...

If you can't make sour cream out of pasteurized milk and you can't make it out of raw milk, how do the big manufacturers do it.  They start with pasteurized milk (it's less likely to cause a disease you generally only see on House).  Then they add back in their own recipe of bacteria.  After the cream is soured, they pasteurize the cream again to kill the bacteria that they added in the first place.  This stops the fermenting process and leaves them a stable product that, with good packaging and refrigeration, could last for two months.

So, how do you build a financial empire out of sour cream?  It turns out to be a great product.  It's well-liked by the American consumer, is fairly straightforward to manufacture, and is a complete pain for people to make themselves.  The trick is distribution.  That requires craft.