Milk + yogurt = fake buttermilk for Ranch dressing?

Any of these buttermilk alternatives will yield tender, flavorful baked goods:

1. Acidified Milk
Add one tablespoon lemon juice or white vinegar to a liquid measuring cup, and add enough milk until it measures 1 cup. Stir, and let sit for five minutes before using. This buttermilk replacement can also be replicated with non-dairy milks.

2. Watered-Down Yogurt
hisk a bit of milk or water into plain, unsweetened yogurt until you get a buttermilk-like consistency. The proportion will depend on the thickness of your yogurt, but generally it'll be around 1/4 liquid with 3/4 cup yogurt. (Only have Greek yogurt? You'll need a little extra water to thin it out.)

3. Watered-Down Sour Cream
Whisk together equal parts sour cream and water. This hack is particular good in pancakes and coffee cakes. (Another cool sour cream trick? Use it to stabilize whipped cream if you're making it ahead of time.)

4. Kefir
No tinkering needed for this one: substitute equal parts kefir for buttermilk in any recipe—just make sure it's unsweetened, unflavored kefir. (Use any additional leftover kefir to make this lovely beet soup.)

5. Cream of Tartar and Milk
Have some cream of tartar in the house from the last time you made meringues? Bingo! Whisk 1 3/4 teaspoons cream of tartar into one cup of milk.

Any of these buttermilk alternatives will yield tender, flavorful baked goods:

1. Acidified Milk
Add one tablespoon lemon juice or white vinegar to a liquid measuring cup, and add enough milk until it measures 1 cup. Stir, and let sit for five minutes before using. This buttermilk replacement can also be replicated with non-dairy milks.

2. Watered-Down Yogurt
Whisk a bit of milk or water into plain, unsweetened yogurt until you get a buttermilk-like consistency. The proportion will depend on the thickness of your yogurt, but generally it'll be around 1/4 liquid with 3/4 cup yogurt. (Only have Greek yogurt? You'll need a little extra water to thin it out.)

3. Watered-Down Sour Cream
Whisk together equal parts sour cream and water. This hack is particular good in pancakes and coffee cakes. (Another cool sour cream trick? Use it to stabilize whipped cream if you're making it ahead of time.)

4. Kefir
No tinkering needed for this one: substitute equal parts kefir for buttermilk in any recipe—just make sure it's unsweetened, unflavored kefir. (Use any additional leftover kefir to make this lovely beet soup.)

5. Cream of Tartar and Milk
Have some cream of tartar in the house from the last time you made meringues? Bingo! Whisk 1 3/4 teaspoons cream of tartar into one cup of milk.

Thanks for your help, everyone!

Buttermilk IS pretty much yogurt whipped up with water to remove the butter, take the butter out from the equation & you're left with yogurt & water.. Just beat them together like you'd try to whip a lassi .. leave it out for a couple of hours to sour. It is real buttermilk, minus the extra added milk solids carrageenan , kosher gelatin etc... If you really want the fake stuff.. Go buy a carton from the local grocery!

I've had success adding lemon juice or vinegar to milk to make "fake" buttermilk. Let it sit for a little while and it will thicken up!

Sour cream would be closer and thin with the milk/lemon juice.