A byproduct from the making of cultured butter and other dairy products across Europe, India and the Middle East, the sour whey known as buttermilk has many uses.
Its sourness has famously been harnessed to tenderise deep-fried chicken by cooks in America's southern states, and it is used by chefs to add richness and tang to dishes as diverse as pancakes, roasted meats and salad dressings.
Jill Dupleix's buttermilk scones. Photo: William Meppem
What is it?
Traditional buttermilk starts with cream, to which lactic acid bacteria starter culture is added. The bacteria eat the lactose and make lactic acid.
This soured cream is creme fraiche, which is then churned. Agitation makes the fat clump together to form cultured butter, and the remaining liquid is buttermilk.
Buttermilk can turn mutton into lamb.Sydney buttermaker Pierre Issa
Industrial buttermilk, on the other hand, is made by adding acid-producing cultures to skim milk. It is less complex in flavour than traditional buttermilk, but in both cases the lactic acid gives buttermilk a pH of between 3.8 and 4.6.
Neil Perry's vanilla and buttermilk panna cotta with quince. Photo: William Meppem
Why do we love it?
"That acid in buttermilk can turn mutton into lamb," says Sydney buttermaker Pierre Issa from Pepe Saya. "It breaks down the muscle fibres in meat, which is why it is used to marinate chicken wings."
He cooks a recipe from Mike McEnearney, of Kitchen By Mike fame, in which a shoulder of lamb is marinated in buttermilk and herbs for 24 hours, then roasted.
"The curds and whey separate and you get cheesy flecks of savoury curd and clean, citrus-like whey," Issa says. "It is beautiful."
In Melbourne, Andreas Papadakis from Osteria Ilaria makes his own butter and therefore has buttermilk. "I use as a seasoning like a chef would use lemon," he says.
For example, he dresses kingfish crudo with buttermilk, its acidity balancing the richness of the fish.
"We make a parmesan cream, let down with buttermilk, to dress brassicas, and I have also used it to add flavour and a little tartness to polenta."
How do you use it?
In baking, the lactic acid in buttermilk reacts with sodium bicarbonate (baking soda) to create carbon dioxide, which adds the lightness to Stephanie Alexander's warming buttermilk pancakes with hot fruit (pictured).
It adds a clean, sour tang to Jill Dupleix's buttermilk scones and balances the cream in Neil Perry's vanilla buttermilk panna cotta with poached quinces.
Make a salad dressing by mixing together 100ml buttermilk, a tablespoon of mayonnaise, a tablespoon of lemon juice and a teaspoon of Dijon mustard in a small bowl and serving over green salad leaves.
Or try a refreshing Indian drink called masala chaas (spiced buttermilk) by blending together 750ml buttermilk with a small knob of peeled ginger, 1 green chilli, 1 tablespoon coriander leaves, ½ teaspoon cumin powder, ½ teaspoon chaat masala spice blend and a large pinch of salt. Serve chilled in tall glasses garnished with more coriander leaves.
Where do you get it?
You can also make an acceptable substitute by mixing 250ml of milk with 20ml of vinegar or lemon juice.
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