Can't you just picture me sitting in my house in some form of bonnet, hunched over a churn and working for hours to produce the world's best buttermilk? That's what I'd be imagining if I saw a post entitled homemade buttermilk before I started baking. The truth to making homemade buttermilk couldn't be farther from that though, and thank goodness for me, bonnets were never my style.
Buttermilk is one of those baking ingredients that is a real pain in the butt. I mean that in the sense that buttermilk isn't present enough in baked goods to normally make it a kitchen staple for most cooks/bakers (and obviously it doesn't keep forever so it's hard to keep on hand for long periods of time just in case). When buttermilk does pop up in a recipe though and you have to go to the grocery store to buy it, the other pain is that they usually only sell it in large quantities.
For me this problem persisted for awhile and I'd find myself skipping recipes with buttermilk in them just to save myself the trouble. Whenever I did make the trip to get buttermilk, odds are at least half the bottle would end up going bad in my fridge from not being used and would need to be thrown out.
That was at least until I discovered that you could make your own buttermilk at home in 5 minutes with barely any work involved. It literally changed my baking life. Now I can make buttermilk on an as need basis. This little trick has saved me time and money, and I hope if you're baking in the kitchen you consider trying it out. I guarantee you'll never go back to store bought buttermilk again. No churns required :)
>1 cup milk
1 tablespoon white vinegar
Pour 1 tablespoon white vinegar in a measuring cup. Pour milk over vinegar in measuring cup until mixture reaches 1 cup line. Do not stir. Let sit for 5 minutes uncovered at room temperature. And that's it! Use homemade buttermilk to your pleasing.
Recipe adapted from Cooks.com