Why she makes her own
The reason is on the counter beside her. Travis bought a container of buttermilk and gave almost four dollars for it, and she is in the middle of a recipe with not quite enough left, so she reaches for a one cup measuring cup to start her buttermilk in. Rather than buy another quart she will not finish, she makes a cup of substitute out of what is already in the kitchen.
She puts the math plainly at the end of the video. She says it is hard to spend four dollars on a little quart of buttermilk when you could make a cup of it from a gallon of milk at two dollars and ninety cents or three dollars, plus a little lemon juice, and that with grocery prices going the way they are, anything that saves at the store helps.
The lemon juice or vinegar way
This one takes a measuring cup and two ingredients. Lynn measures one cup of whole milk, which is the milk they buy, and says she is not sure how it does with low fat or skim. She invites viewers who have tried other kinds to leave what they know in the comments rather than guessing at it herself.
To that cup of milk she adds one tablespoon of either lemon juice or white vinegar, whichever one you have. Her rule on that is simple: use what is already at home instead of buying something special. Then she gives it a mix and lets it set for around five to ten minutes while she gets the rest of the recipe together.
It does not take the full ten minutes to see it working. She brings the cup to the camera and shows how quickly the lemon juice is already turning the white milk into buttermilk, and points out that you can see it on the spoon.
The sour cream way
The second version uses sour cream, and Lynn says it is the one to reach for when you are making a cake, because the sour cream gives it a little more creaminess. She spoons sour cream into a measuring cup, taps it on the counter and fills it to the three-quarters line, making sure it really is three-quarters of a cup and not just piled up.
From there you have a choice. She says you can fill it the rest of the way to the one cup line with whole milk or with plain water, and she uses milk. Mixing it takes more work than the first version, and once the milk is worked into the sour cream she adds not a whole tablespoon but a few drops of lemon juice, probably a fourth of a teaspoon and finishes stirring.
If it comes out thicker than you want, she says you can add a little dab more milk to thin it, though she leaves hers as it is. Compared with the lemon juice version, she says the sour cream one has more of that tangy taste you get with buttermilk.
How she uses it
The batch she makes in this video goes straight into supper. She says she is going to use it in her cornbread recipe, and the sour cream one is the version she points to for cakes.
She is honest about what it is. It is a substitute, and she says the texture is a little different from what you are used to buying, but it acts the same in your recipes as the store-bought buttermilk. She does not say on camera how long either version keeps. Both are shown on the video page, her self-rising and cake flour batches are another baking staple she makes instead of buying, and anything else can go to Ask Lynn.