245 g of buttermilk is 1 cup. Buttermilk is almost the same weight as milk, just 1 g heavier per cup, because it is cultured milk with a slightly higher solid content. Its real importance is not its weight but its acidity: buttermilk activates baking soda, tenderises crumb, and gives pancakes, biscuits and fried chicken their characteristic tang.
All figures on this page are approximate, and they come from USDA, measured poured. When a recipe has to work the first time, verify with a kitchen scale.
Conversion table
| Cups | Grams of buttermilk |
|---|---|
| 1/4 cup | 61.2 g |
| 1/3 cup | 81.7 g |
| 1/2 cup | 122.5 g |
| 2/3 cup | 163.3 g |
| 3/4 cup | 183.8 g |
| 1 cup | 245 g |
| 1 1/2 cups | 367.5 g |
| 2 cups | 490 g |
| 3 cups | 735 g |
| 4 cups | 980 g |
Quick reference: 100 g of buttermilk is about 0.41 cups, and 50 g is about 0.2 cups. All figures are approximate; verify with a kitchen scale when it matters.
Method and source
The figure on this page comes from USDA, measured poured. Tangy cultured milk that tenderises batters and activates baking soda. Pancakes, biscuits, fried chicken and ranch dressing.
A note on disputed figures. USDA lists cultured buttermilk at about 245 g per cup; King Arthur rounds it to 227 g.
All results on this page are approximate. Ingredient weights vary with brand, humidity, temperature and how firmly you pack the cup, so when a recipe has to work the first time, weigh the ingredient on a kitchen scale and use the numbers here as a guide.
Worked examples
Buttermilk pancakes for a crowd
A pancake recipe serving six uses 490 g of buttermilk, which is 2 cups. Whisk the buttermilk with the eggs first, then fold in the flour and baking soda. The soda reacts with the acid in the buttermilk immediately, so cook the pancakes straight away rather than letting the batter sit.
Fried chicken with an overnight soak
A fried chicken recipe soaks eight pieces in 490 g of buttermilk, 2 cups, with salt and hot sauce overnight. The buttermilk tenderises the meat and helps the coating stick. The exact amount matters less than covering the chicken completely, so use a dish that fits the pieces snugly.
Buttermilk biscuits for a Sunday lunch
A biscuit recipe uses 245 g of buttermilk, exactly 1 cup, stirred into flour, butter and baking powder. The dough should be shaggy and just combined, not smooth: overworking it makes tough biscuits. The acid in the buttermilk reacts with the baking powder to give the biscuits their lift.
Practical guidance
Dairy products vary in thickness, so the method matters. Thin dairy like milk and buttermilk is poured into a jug; thick dairy like sour cream, yogurt and cream cheese is spooned into a dry cup and levelled, pressing out air pockets as you go. Bring dairy to room temperature before adding it to a batter unless the recipe says cold, because cold dairy can seize melted butter and leave lumps. If a recipe gives dairy by weight and you only have cups, use the table below rather than guessing: a cup of cream cheese is noticeably heavier than a cup of milk, and the two are not interchangeable by volume.
Scaling is straightforward once you know the cup weight. Doubling a recipe that calls for 245 g of buttermilk means measuring 490 g, or 2 cups, and tripling it means 735 g, or 3 cups. Halving is just as easy: half a cup is 122.5 g. The key is to scale every ingredient by the same factor, because changing one ingredient without changing the others throws the recipe out of balance. A cake scaled by half still needs half the flour, half the sugar, half the butter and half the buttermilk, not just half of one of them. If you are scaling a recipe by an awkward factor, like two thirds, weigh the buttermilk rather than trying to measure two thirds of a cup in a jug, because the jug markings are not precise enough for fractions of a cup.
When should you weigh buttermilk instead of measuring it? Whenever the recipe has to work the first time, and whenever the amount is large. A kitchen scale costs less than a single failed cake, and it removes the biggest source of variation in home cooking: the way ingredients pack into a cup or a spoon. Put the bowl on the scale, press tare, and add the buttermilk until the display shows the number you need. There is nothing to wash afterwards except the bowl, and the result is the same every time. For small amounts, a level spoon is accurate enough, and for liquids, a jug is fine, but for anything where precision matters, the scale is the tool to reach for.
Storage. Refrigerate; use within 2 weeks.
- Use buttermilk with baking soda for the best rise.
- Freeze leftover buttermilk in half-cup portions.
- Do not let batters with buttermilk and soda sit before cooking.
Frequently asked questions
Can I make buttermilk from milk and vinegar?
Yes. Add one tablespoon of lemon juice or white vinegar to a cup of milk, which is 245 g, and let it sit for ten minutes until it curdles slightly. It works well in pancakes, cakes and biscuits, though it lacks the thickness of real cultured buttermilk.
Is buttermilk the same as soured milk?
No. Real buttermilk is cultured milk, fermented with bacteria that give it a clean tang and a thick texture. Soured milk is milk that has gone off, and it tastes unpleasant. The milk-and-vinegar trick is a substitute, not soured milk.
Why do recipes pair buttermilk with baking soda?
Buttermilk is acidic, and baking soda needs an acid to produce the carbon dioxide that lifts a batter. The pairing is one of the oldest tricks in baking, and it is why buttermilk pancakes are fluffier than pancakes made with plain milk.
Can I freeze buttermilk?
Yes, and it is a good idea, because buttermilk is usually sold in large cartons and recipes use a cup at a time. Freeze it in half-cup portions in ice cube trays or small containers, and thaw it in the fridge before using.
How long does buttermilk keep?
About two weeks in the fridge once opened. It is already cultured, so it keeps longer than milk, but if it smells very sharp or develops mould, throw it away.
Common mistakes to avoid
The most common mistake with dairy is measuring a thick product like sour cream or cream cheese in a jug, where it clings to the sides and reads low. The second is adding cold dairy to a hot mixture, which can make it split or curdle, especially with cream cheese and sour cream. The third is boiling a sauce after the cream has been added, which breaks the emulsion and leaves a greasy, separated sauce. The fourth mistake is measuring dairy that has just been shaken or stirred vigorously, because the air bubbles take up volume and the reading comes out high. Finally, do not freeze dairy products that you plan to use in baking, because freezing changes their texture: cream cheese becomes grainy, sour cream separates, and yogurt turns watery, and none of them recover properly on thawing.