A yoghurt from Kappacasein, fermented twice to create a complex, tangy flavour
It was Jamie Montgomery—he of Montgomery cheddar fame—who gave Bill Oglethorpe the idea for his Kappacasein natural yoghurt. “Jamie was having some problems with TB on his farm, so was looking to pasteurise his cheddar for a time, but he didn’t want to compromise on taste,” Bill explains. Jamie sought advice from a French cheesemaker, who told him to ripen the milk with a starter culture before pasteurisation, “so you get those complex raw milk flavours, which stay in the milk after it’s pasteurised.” After pasteurisation, Jamie could add the starter culture again to kickstart the cheesemaking process, creating a pasteurised cheddar with an unparalleled ‘unpasteurised’ taste.
It made Bill, a man famed for his raw cow’s milk cheeses, made with his own natural starter culture, stop and ponder. What if he made yoghurt like that? Could he make yoghurt of the same depth and complexity as his beloved Bermondsey Hard Pressed cheese? “To make yoghurt you need to denature the proteins, and that requires boiling. You can’t make raw yoghurt. People ask for it, but it’s impossible to create the thick texture without denaturing the proteins and precipitating the calcium—then, once it’s cool, acidifying it by adding the starter again.”
The starter Bill uses is one he makes himself, by incubating raw milk overnight and relying on the milk’s naturally occurring bacteria to begin lacto-fermentation. This starter is added to the fresh milk, which he picks up from the Bore Place farm in Kent each morning, and as Bill drives the two hours back to his south London dairy it mixes and ripens, creating the distinctive tang we associate with his cheese.
Only once Bill gets back to Bermondsey does he separate the milk destined for cheese from the milk used to make yoghurt. The latter is boiled and chilled, and more of the starter is added to start the curdling process. “I think using pre-ripened milk is the distinction that makes it special,” he continues. “The first time the starter culture is in warm, raw milk, driving the fermentation alongside the other bacteria present in the milk, and the second time the starter culture is in pasteurised milk working on its own.”
Kicky and tart
The result is quite something: kicky and tart, with a touch of sweetness that comes from full fat, organic milk. The texture is thick enough for granola, but smooth enough for a lassi—or at least so Bill is told by his customers of Indian heritage, who also use it to cool down particularly spicy dishes. Bill serves his for breakfast with roasted buckwheat, pumpkin and sunflower seeds, and occasionally Seville marmalade from Rosebud Preserves, which adds “a lovely flavour and texture”. “I’ve been eating quite a lot of it recently,” he confesses—and, now we’ve tried it, so will we.