If butter tastes better, homemade cultured butter tastes best, says Pierre Issa, maker of Pepe Saya artisan butter.
Try Issa's recipe with our best of butter recipes.
The starting point is very good cream. I look for organic, as fresh as possible and with as high a fat content as I can find - the ideal is 40 to 50 per cent. Farmers' markets are your best go-to.
Ageing the cream is the next step. In this process we're trying to grow lactobacillus.
As the pH drops, the cream sours, so taste every couple of days. I age my cream in the refrigerator for a week until it smells like it has turned slightly.
When the cream reaches the desired sourness, it needs to be warmed to 37.5C to create the ideal environment for bacteria to grow. When dealing with bacteria and culture, hygiene is very important, so at this stage sterilise your bowls and utensils. Make sure you wash your hands thoroughly before you continue or wear disposable gloves.
Once this is done, heat the cream gently to prevent scalding, best done in a double-boiler or bowl over a saucepan of simmering water, stirring frequently to distribute the heat. Monitor the temperature with a thermometer, or dip your little finger in the cream and count to 10. If you can stand the temperature and only need to pull it out at the count of 10, you've hit the sweet spot. If it remains cool, give it a little more time and test again. Too hot and you'll need to let the cream cool a little (up to 45C is fine).
At this point, add the lactic culture, either in crystal form (available at cheeselinks.com) or in the form of active crème fraîche or live buttermilk, which functions a bit like a mother or starter in sourdough-making.
Check the ingredients of whatever crème fraîche or buttermilk you intend to use - it needs to have active lactic culture. Much of the buttermilk available is not live buttermilk; rather, it's a combination of skim milk, skim milk powder and culture. Farmers' markets are a reliable source of the real deal.
As a general equation, I add half a cup of culture for every litre of cream. When the culture is first introduced to the warm cream, it eats the lactose and converts it into lactic acid.
Once the cream is inoculated, a stable temperature of between 20C and 37.5C needs to be maintained for at least 20 hours. At home, the best way to do this is to place the cream in a saucepan with a lid and wrap it in a thick woollen blanket. Place the whole bundle in the warmest part of the house where it won't be disturbed.
Next, the mixture needs to set in the fridge for 24 hours (unwrap it first) - the mixture will resemble thick custard. You've just made crème fraîche.
Beat the crème fraîche on high speed in a heavy-duty electric mixer fitted with a paddle attachment until it thickens and splits; it will develop a slight yellow tinge and spray out buttermilk. Reduce to the lowest possible speed and keep beating until the butter comes out of the cream and starts to resemble popcorn. This is where the fat content of the cream comes into play - if you've used cream with 50 per cent fat, you'll have about half buttery solids and half buttermilk.
Tip all the mixture into a colander over a large bowl and refrigerate the buttermilk in a sterile container for up to two weeks.
The butter "popcorn" then needs to be rinsed of any remaining buttermilk. Place the colander in the sink and pour about a litre of chilled water over, shaking the colander until the water runs clear.
Next, knead and squeeze a handful of butter at a time to extract any remaining liquid until the butter feels like playdough. Push it into a ring mould lined with baking paper, fold the paper over to enclose, then wrap in foil and plastic wrap. Refrigerate in an airtight container for up to three months.