How to Make Buttermilk

Buttermilk is one of those quietly magical ingredients that transforms everyday baking. With its light acidity and subtle creaminess, it brings tenderness to cakes, fluffiness to pancakes and a beautiful rise to soda breads. It may not always be something you keep in the fridge, but the good news is that homemade buttermilk is quick, simple and just as effective as shop-bought.

Whether you are halfway through a recipe and realise you need it, or you simply want to try making it yourself, learning how to make buttermilk at home is a handy skill for any cook. With only two ingredients and five minutes of your time, you can have fresh buttermilk ready for baking, marinating or dressing.

What Is Buttermilk?

Traditionally, buttermilk was the liquid left behind after churning cream into butter. This old-fashioned version was thinner, naturally fermented and slightly sour, often used in rural cooking and baking. Today, most buttermilk sold in the UK is cultured buttermilk. This means milk has been combined with live cultures that create lactic acid, giving it that familiar tang and thicker consistency.

In cooking, buttermilk’s acidity reacts with raising agents like bicarbonate of soda to produce carbon dioxide, which helps bakes rise. It also tenderises batters and doughs, making it popular in American-style pancakes, scones, cornbread and fried chicken marinades.

How to Make Buttermilk at Home

If you do not have buttermilk in the fridge, you can make a quick substitute using milk and an acid such as lemon juice or vinegar. This combination mimics the acidity and thickness of real buttermilk and works well in almost all recipes.

Pour 250 millilitres of whole milk into a jug or bowl. Add one tablespoon of lemon juice or white wine vinegar, stir gently and leave it to sit for five to ten minutes at room temperature. The milk will begin to curdle slightly and thicken. This is exactly what you want. Once it has developed a slight tang and a texture similar to thin yoghurt, it is ready to use.

If you are using semi-skimmed milk, the mixture will still work but it may be slightly thinner. Avoid using skimmed milk, as it will not curdle well and lacks the richness needed for baking.

Other Buttermilk Substitutes

If you are short on fresh milk, you can use yoghurt or crème fraîche to create a similar effect. Mix 180 millilitres of yoghurt with 70 millilitres of water or milk to loosen it. This blend offers the same acidity and texture and can be used in most baking recipes that call for buttermilk.

Kefir is another excellent substitute. As a cultured milk drink, it already contains the live bacteria and acidity that make buttermilk effective. It is slightly more tangy and works beautifully in breads, muffins and pancakes.

When to Use Buttermilk

Buttermilk’s acidic profile makes it a star in baking. It reacts with bicarbonate of soda to give rise and structure to recipes without using yeast. Irish soda bread is a classic example. Buttermilk also creates a tender crumb in cakes and muffins, particularly when paired with oil or melted butter.

In pancakes and waffles, buttermilk brings lightness and a slight tang that cuts through sweetness. In chocolate cakes, it balances the richness of cocoa. It can also be used in savoury dishes like marinades for fried chicken, where its acidity tenderises the meat while keeping it juicy. It even makes a lovely base for salad dressings, adding creaminess without overwhelming richness.

Chef Tips and Tricks

For best results, use your homemade buttermilk immediately. Although it can be stored in the fridge for a couple of days, it is most effective when freshly made. If you are scaling up the recipe, keep the ratio at one tablespoon of acid to every 250 millilitres of milk.

Mary Berry recommends using buttermilk in place of milk for a more delicate scone texture. James Martin often highlights its ability to create fluffier pancakes. For a tangier taste, some bakers prefer to add a teaspoon of yoghurt along with lemon juice to mimic the fuller flavour of cultured buttermilk.

Common Mistakes to Avoid

One common issue is not allowing enough time for the mixture to curdle. If you use the milk and acid too soon, it will not have the same effect in baking and your rise may be limited. Always wait the full five to ten minutes before using.

Another mistake is using the wrong milk. Plant-based milks or skimmed varieties often fail to curdle properly. If you need a dairy-free version, choose a plant milk with higher protein such as soy and combine it with lemon juice. The result will not be as rich, but it can still serve the purpose in pancakes and muffins.

Sustainability and Waste Reduction

Making your own buttermilk helps reduce packaging waste and makes use of ingredients already in your kitchen. If you have milk that is near its use-by date, turning it into buttermilk for baking is a clever way to use it up. Choosing organic milk and natural vinegars or fresh lemon juice adds another layer of sustainability to your cooking.

Final Thoughts: A Simple Kitchen Staple

Buttermilk may seem like a specialist ingredient, but with a splash of lemon juice and a bit of waiting time, you can recreate its tangy magic at home in minutes. It adds lightness, flavour and texture to a huge range of recipes and gives your baking that unmistakable homemade touch. Once you have made your own, you may never go back to shop-bought.