You'll find speciality restaurants in the United States and in the United Kingdom that brag about frying their chips in duck fat. A couple of years ago it was recommended as a "twice a year" treat because of its cost.
But in South Africa duck fat is today cheaper than butter anywhere there is a Woolworths food store.
Woolworths' own-brand butter currently retails at the equivalent of R161 per kilogramme. It's free-range duck fat is R122 per kilogram – just short of a quarter less expensive.
The price difference is not unique to Woolworths. A Business Insider South Africa survey found that the price of duck fat at independent retailers range from R166 per kilogramme in Johannesburg (at Thrupps in Illovo) to R244 per kilogram from the Cape Town Online Market – for duck fat imported from France.
Butter prices, meanwhile, are universally high across retailers. At Pick n Pay, Ladismith salted butter goes for the equivalent of R131 per kilogramme, or some 13% more than Woolworths duck fat.
Various independent grocery stores quoted remarkably similar prices for butter – in the region of R65 for a 500g block – with one saying customers were "extremely aware of the price of butter", making for a minimal markup.
Milk production dropped in 2017 even as consumers switched to full-cream milk and started using more butter, inspired by banting-style high-fat diets.
Whether you should use duck fat instead of butter to, say, fry bread for an egg toastie, is a more complicated question. Chefs swear by duck fat for its taste and mouth feel – but dieticians generally recommend steering clear of animal fats and reaching for the olive oil instead.