What is buttermilk?
Buttermilk, despite its name, is low in fat, varying between 0.6 percent and 2.0 percent per 100ml depending on the brand. True buttermilk is the remnant liquid from making butter and some cheeses. This is thin and watery; very different from thick commercial buttermilk, which is both opaque and white. These days commercial buttermilk is made from no-fat or low-fat milk to which a culture is added. Before you open the carton, always shake to combine the contents; if the carton is already opened, stir it to ensure any thinner liquid that may have separated is combined with the thicker liquid.
What is the purpose of buttermilk?
Buttermilk is a liquid and therefore adds hydration to dry mixture, while the acidity reacts with bicarbonate of soda (an alkaline) adding extra lightness to cakes, muffins, scones, and pancakes. It has a distinct lactic tang, like yoghurt and can be used to add a fresh note or to balance sweetness in recipes, in the way lemon juice might.
Looking for a buttermilk substitute?
Here is a list of buttermilk alternatives.
Test Kitchen favourite – Greek yoghurt
Due to the thicker consistency this substitute requires thinning with low-fat milk (or use water). Use 2-parts yoghurt to 1-part low-fat milk.
To substitute 1 cup (250ml) buttermilk: Combine ⅔ cup (190g) Greek yoghurt with ⅓ cup (80ml) low-fat (2%) milk until smooth.
Result: This is the Test Kitchen’s number one rated substitute due to the near similar result and taste to buttermilk.
Best used: Can be used as a substitute widely.
Plain kefir
To use, shake the kefir first and use the same quantity listed for buttermilk in the recipe.
Result: Kefir is not a common ingredient in everyone’s fridge, however if it is in yours, it makes a terrific substitute and will achieve very similar results in cooking and baking to buttermilk.
Best used: Can be used as substitute widely.
Sour cream
Due to the thicker consistency and higher fat content this substitute requires thinning. Use 1-part sour cream to 1-part milk or water.
To substitute 1 cup (250ml) buttermilk: Combine ½ cup (140g) sour cream with ½ cup (125ml) milk or water until smooth.
Result: The outcome is like using buttermilk, however due to the increased fat content may be marginally denser, however the tangy flavour is a good match for buttermilk.
Best used: When the amount of buttermilk is not greater than 1 cup as the fat content if used in a cake could potentially create a different result.
Milk
Use the same quantity as listed in the recipe as for buttermilk.
Result: You will miss out on the rising boost and lactic taste of the buttermilk.
Best used: As a last resort and/or if the recipe requires a smaller amount. It is an okay substitute for scones and pancakes, though they will not be quite as fluffy. However, we do not recommend attempting to use it in a cake.
