I often use buttermilk when baking. The slight tang it adds can wake up a flavor profile. But I don’t always have it on hand. There are 2 ways to make it at home; one in a pinch, one ongoing long term.

What exactly is Buttermilk?

Buttermilk is what remains after butter is made from cream. Making butter is a step beyond making whipped cream – if you keep on mixing, shaking or otherwise agitating the whipped cream, solids will form (the butter) and the liquid comes out (buttermilk). Store buttermilk tends to be thicker and more viscous than the buttermilk you would get at home after make butter, but it’s basically the same.

So what’s the short cut?

If you don’t have any buttermilk in your fridge at all, you can make a fair compromise using milk and an acid – usually either vinegar or lemon juice. Measure out the milk you need minus a teaspoon or two, and add some vinegar or lemon juice. Then let it sit at least 5 minutes. The milk will start to curdle slightly, and also thicken a bit, and the taste will approximate that of real buttermilk. No one would know you used a short cut.

And how can I make buttermilk at home?

As above, if you are actually making some butter, you will create buttermilk as a by-product.

But there is also an ongoing way to keep yourself in stock. If you’ve purchased a quart of buttermilk (or made some in the past from butter), don’t use it all up. When the container is down to about 1/4 remaining, add some milk. Let it sit out overnight on the counter. The buttermilk cultures will start to take over the milk, and voila! Your container is now full of real buttermilk. Put it back in the fridge, and use whenever you need it. When you get down to 1/4 of the jug, add milk again. It’s a never ending cycle.

I find this new buttermilk just as thick and delicious as the original – maybe even better. See how it coats the glass? It’s not as thick as yogurt, but much thicker than regular milk.

Just remember to keep the proportions: 1/4 original buttermilk and 3/4 new milk added.