I've read somewhere (it was a vanilla cake recipe, IIRC) that 3/4 cup yogurt plus 1/4 milk is buttermilk. A recipe (buttermilk biscuits) calls for buttermilk and I'd like to know if I can use this formula to make buttermilk.

  • Yogurt plus milk actually equals more yogurt, with a little heating. Google "make yogurt" for many examples. You can make buttermilk in much the same way using buttermilk (google "make buttermilk").
    – BobRodes
    Jun 12, 2014 at 3:18

4 Answers 4


Technically, this is not precisely buttermilk, but it's pretty close in both composition and usage.

The term "buttermilk" can actually refer to a wide range of fermented milk varieties. Traditionally, buttermilk was produced by allowing natural bacteria present in cream to ferment some of the sugar lactose into lactic acid. This made churning butter from the cream easier and also helped protect the cream from spoiling. After the butter was churned and removed, the liquid that remained would be your buttermilk (today referred to as "traditional").

Nowadays, mass-produced "cultured" buttermilk is produced by taking pasteurized low-fat milk and introducing bacterial cultures to produce lactic acid in a similar fashion. That's similar to how yogurt is produced, but yogurt is generally allowed to ferment for longer until the milk proteins set and thicken. There are many varieties of yogurt with slightly different cultures from each other and from cultured buttermilk, and the beginning fat content of the milk can differ too.

So, technically these are distinct, but if you use milk to thin out yogurt, you're producing a beverage that (like buttermilk) contains lactic acid, producing that distinctive tangy flavor, and which (like buttermilk) is somewhat thicker than milk. Your identified ratio is the same as other recommendations that I found while searching around, so you can definitely use this to substitute.

There are also other substitutions available. This thread also covers similar information, in addition to being a colorful exploration of related terms.


While Yogurt and milk are not traditional buttermilk, modern buttermilk is very similar to yogurt. Traditional buttermilk is actually the liquid you have left over after you've made butter, while modern buttermilk is a cultured product.

Generally, in baking, buttermilk is used for its acidity and protein content. If you want a viable substitute, milk and yogurt can work, or milk and some lemon juice. It's a good idea to let these mixtures sit a bit after you've combined them, to allow the milk to curdle and acidify.

If you were to make butter at home, one way to do so is to inoculate some heavy cream with a yogurt culture. This introduces bacteria into the cream which will acidify it and cause the fat in the heavy cream to glom together more easily.

Once you've fermented the cream as you would ferment yogurt (in a warm place for about 4 to 12 hours), the result is something called creme bulgare. This is similar to creme fraiche.

If you churn the cooled creme bulgare, you will cause the fat in it to conglomerate through mechanical action. I use a food processor to do this. You process the creme until it separates, you'll clearly see the butter clumping together and a liquid separating from it, this liquid is buttermilk.

To finish off the butter, I strain the mixture, save the buttermilk, and cool the butter until it is no longer soft. Once it's not soft, I put it in cheesecloth and squeeze the remaining buttermilk out of it. Squeezing the buttermilk out of the cooled down butter is much easier since the butter will not be able to pass through the cheesecloth. Additionally, it's a good idea to do this since it ensures the butter last longer.

  • 3
    I'm not sure where you're from, but 'buttermilk' in the US rarely refers to the leftover liquid from butter making anymore. It's typically 'cultured buttermilk', which is a fermented product similar to yogurt. See cooking.stackexchange.com/q/784/67
    – Joe
    Jun 11, 2014 at 18:23
  • @Joe: I'm from the US, I simply strove to give a definition that's closer to buttermilk's namesake. Even though this isn't what's typically sold in stores as "buttermilk", it's still buttermilk. Seems like logophobe covered the current and past usage of the term well.
    – Ron
    Jun 11, 2014 at 18:30
  • the problem is that there's no retronym for the 'original' buttermilk, so it's difficult to differentiate between the two -- but if someone's asking about how to deal with a modern recipe, telling them about the antiquated usage of the term, particularly without mentioning that there's something else that the term more than likely refers to, isn't useful.
    – Joe
    Jun 11, 2014 at 21:25
  • I agree, I just never thought that modern butter milk could be anything different. I always just get buttermilk when I make butter. I've never had experience with it before that. I'll leave my answer up in case someone looks up buttermilk and they end up here. There is some added content (how to make butter/buttermilk) and taken together with our comments, I think it might just end up being useful for someone else.
    – Ron
    Jun 11, 2014 at 22:17

I can't find "buttermilk" anywhere in the recipe link that was originally referenced (http://parsleysagesweet.com/2013/05/18/tourte-milanese-a-meal-en-croute/).

Regardless, the information you presented in your post seems to refer to "cultured buttermilk" and not "the milk left over from making butter."

If the yogurt you're using has active cultures (look at the ingredients list), then the yogurt/milk (whole milk) mix will result in something reasonably close to "cultured buttermilk" in flavor, body, and acetic enough for activating baking soda if your recipe calls for that.

  • Sorry, I linked to the wrong recipe! I edited the question and fixed it.
    – Gigili
    Jun 12, 2014 at 3:18
  • 1
    The recipes author states that the yogurt and milk mix gives a similar effect. The link on how to make buttermilk calls for adding vinegar to milk to, in effect, curdle the milk. Neither are actual or cultured buttermilk, just good substitutions for the recipe. P.s. I think I'm going to make these :).
    – Michael E.
    Jun 13, 2014 at 17:56

Yoghurt + Milk != Buttermilk.

It is made by shaking Cream as long as possible. The first you'll see in this process, the Cream will become whipped cream. If you keep on shaking, the water and fat will separate from each other. The fat will agglomerate and is further on called butter.

The separated water, the leftover, is called buttermilk (traditionally).

The mixture you mentioned is somewhat cultured buttermilk with some substitute for the removed fat and stuff which makes it less liquid and regulate the acidity. Some more information can be gained here:


My guess it, that the recipe is meaning a cultured type of buttermilk, because most people would associate buttermilk with cultured buttermilk as a replacement to the traditional meaning.

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