Sour Cream Info

A Kitchen Staple

Sour Cream has been a staple in the kitchen ever since folks have been milking animals.

The cream was often allowed to rise and be skimmed to make butter, but if this did not happen soon enough, the natural bacteria would soon spoil the cream. 

Our ancestors soon realized that if they controlled this process, the cream developed into a nice thickness with pleasant flavor. Plus, it could be kept for a much longer period.

With refrigeration today, we find that Sour Cream keeps for a few weeks and has many uses:

  • on its own with fresh fruit and berries 
  • for thickening sauces 
  • in soups and stews. 
  • batters and cakes 
  • also a great base for dips and spreads

What is Sour Cream

Traditionally, it was simply a matter of allowing some of the cream to rise overnight in a cool space and then partially skimming. Once the cream was collected, it was simply allowed to rest at room temperature while the natural bacteria from the farm would begin to convert the lactose to lactic acid, and this became the sour cream. Once the cream was sour, much of the lactose was no longer available to ferment and it would keep for much longer. So in one sense, this was simply a form of cream preservation, but the tangy nature of this was just such a great complement to so many foods.

Today, we can buy our cream at the store and make it at home. Since most of this is now pasteurized, we must find another source of bacteria to convert the lactose. This can be as easy as adding a small amount of buttermilk that still has an active culture, or using a lab prepared culture. The problem with using buttermilk from the store is that we are never quite sure of how active the culture is, since it has endured the rigors of the retail chain.

To make sour cream, you just need buttermilk and heavy cream, or half and half. Heavy cream will result in a thicker sour cream (closer to Creme Fraiche), so choose milk/cream balance based on the texture you're looking for. Sour cream is just another version of cultured milk/cream. 

The starter cultures typically used for making sour cream are normally what we refer to as Aromatic or Buttermilk cultures (i.e., Lc. lactis subsp. lactis biovar.diacetylactis and L.mesenteroides subsp. cremoris) similar to those used for cultured buttermilk. This tends to add a bit of buttery flavor and a little open texture, due to a small amount of CO2 being produced. 

Traditional sour cream contains 18 to 20 percent butterfat and gets its characteristic tang from the lactic acid created by the bacteria. Sour cream is usually not fully fermented and still contains lactose, and like many dairy products, must be refrigerated unopened, as well as after use.

Variations in Style

There are two styles of sour cream, Cultured sour cream and Acidified sour cream.

  • The Cultured Sour Cream, which is not less than 18% fat, uses a bacteria culture to convert lactose.
  • The Acidified Sour Cream uses an acid addition to provide acidity in the milk. The lactose remains in the finished product

In addition there is a huge range of several fat reduction categories.

  • Reduced fat: 13.5% fat
  • Light: 9% or less fat
  • Low fat: 6% fat or less
  • Non Fat: 1% or less fat

Commercial additives can include: modified corn starch, sodium phosphate, guar gum, carageenan, locust bean gum, "natural" flavors, gelatin, rennet.

These are added to increase the thickness and texture, as well as to prevent separation of whey.