Homemade Cultured Buttermilk

Back in the day, buttermilk was a different beast. It seems the story is this: Raw milk was not churned right away since a certain volume of cream would need to be collected and the milk and cream needed time to sit and separate. Bacteria naturally found in the milk would multiply, the milk would sour, and the "buttermilk" that was left behind after churning was, as a result, not the same as what is left after making your own butter from pasteurized and homogenized milk. And neither of these versions is the same as the cultured buttermilk sold commercially at your local grocery today.

Old-Fashioned Buttermilk

Old-fashioned buttermilk occurs during the process used to transform cream into butter. The slightly acidic taste comes from bacteria naturally present in the cream, which is allowed to sour slightly while waiting for the cream to rise to the top. Old-fashioned buttermilk was most commonly added to recipes as a way to boost nutrition. Traditional buttermilk is not available for sale in grocery stores in the United States, but you might find it through specialty dairy producers. It has a rich, buttery taste and only a gently acidic tang. The thin liquid contains almost no fat, as it is removed during the butter-making process.

In a recipe calling for old-fashioned buttermilk, you can substitute water with a small amount of lemon juice.

Cultured Buttermilk

To produce cultured buttermilk, low-fat or non-fat milk must be acidified with bacteria cultures similar to those found in cream during the butter-making process. The taste of cultured buttermilk differs from traditional buttermilk, however. The sour liquid resembles yogurt, with a thicker texture than traditional buttermilk. It is used primarily for cooking rather than drinking.

Cultured Buttermilk Substitutions and Options

Because of their significant differences in taste and texture, old-fashioned and cultured buttermilk cannot be substituted for one another. See Buttermilk Substitution

Homemade Cultured Buttermilk

Cultured buttermilk is often called for in baking (the acidity activates baking soda), is used to make dressings and sauces, or can simply be drunk by the glassful.

Notes:

• Some recipes indicate that you should pasteurize your milk (at 180°F) before culturing or at least warm it to 76°F. This step is entirely unnecessary, as store-bought milk is all pasteurized before it hits the shelves.
• When buying buttermilk from the store, just be sure the container says “live cultures” or else this recipe won't work. Alternatively, you can use dehydrated buttermilk cultures. Sour cream containing “live cultures” would also work; buttermilk and sour cream use the same cultures. Most commercial sour cream is pasteurized to lower the risk of food poisoning, meaning that any live bacteria are destroyed before they make it into the final product.
• Once you have buttermilk going, you can use your existing buttermilk to keep on making it for batches on end.
• Keep your buttermilk about 6 feet away from other ferments or cultures you might have going in your kitchen, including sourdough.

Recipe

2 tablespoons cultured buttermilk (store-bought or activated dried starter)
2 cups milk (whole, 2%, or skim, depending on your nutritional needs and preferences)

In a mason jar or other glass container, thoroughly mix the starter and milk. Cover with a coffee filter or piece of cheese cloth (do not seal tightly with a lid) and leave to culture out of drafts at a warm room temperature (between 70-78°F is recommended) until milk has clabbered (10-24 hours). Leave the container undisturbed.

To test if the milk has thickened, tip the jar slightly. It should move away from the wall of the jar as a single mass. Just as with yogurt making, once the milk sets, it will get more tart the longer you allow the culturing to continue.

Refrigerate to halt culturing for at least six hours. Stir before using.

Always remember to save back at least 1/4 cup for your next batch! For re-culturing, it is recommended to make a new batch of buttermilk within 7 days. See below for "Taking a Break from Making Buttermilk"

Makes: 2 cups

Shelf life

The lactic acid gives buttermilk its tangy flavor and also acts to keep any other bacteria and molds from multiplying. The probiotic bacteria also produce diacetyl, which gives it a buttery flavor. Buttermilk continues to ferment throughout its time in your refrigerator and the bacteria that produce diacetyl decline, losing the buttery flavor, while the lactic acid continues to be produced, making it sour.

For using in drinks and uncooked dishes (like buttermilk ranch dressing), buttermilk is best while it is freshest. As buttermilk ages, it thickens and begins to lose its buttery flavor qualities. It can still be used for baking and meat tenderizing, which depend on its acid qualities.

Buttermilk can last up to 14 days in the fridge after it has been opened and may last beyond its expiration date if unopened. However, it’s always best to use it as soon as possible. An unopened carton will last longer than an opened carton.

You can freeze buttermilk if you want to use it in baking. Freezing it will alter the consistency and cause it to clump and separate, so you won't want to use frozen buttermilk for drinking or uncooked recipes. It will still have its acid content which is what is desired for baking, as it helps the baked products rise. You can also use it for tenderizing meat.

Once your buttermilk is chunky, and you can't pour it, or if it has visible mold, it's time to throw it out. Another sign is a strong sour odor.

Taking a Break from Making Buttermilk

If a longer break is necessary between batches, preserve some active cultures by freezing or drying. Neither method is completely reliable, but our customers report a fair amount of success with both.

Short Breaks, Up to 4 Weeks

• Put fresh, active buttermilk in clean freezer-safe containers. Ice cube trays are convenient.
• For each cube, add the amount of buttermilk that it will take to culture 1 cup of milk, 1 tablespoon.
• Once frozen, store the cubes in an airtight container in the freezer.
• When ready to make buttermilk again, remove enough from the freezer to make a new batch, 1 cube per cup of fresh milk.
  Thaw before adding buttermilk to prepared milk.
• The longer the buttermilk is frozen, the less potent it will be as a starter culture. It may be necessary to use up to twice the amount if the buttermilk was frozen for 3-4 weeks.

Long Breaks, Up to 3 Months

• Spread a small amount of starter on a piece of unbleached parchment paper.
• Leave the buttermilk to dry in a warm, safe spot no more than 80°F.
• Once it is completely dry, store in a zip lock bag in the refrigerator.
• Under ideal conditions, the starter will keep for up to a few months.
• To rehydrate the buttermilk, follow activation instructions included with the starter.