Asked by: Amanda Hart, Cardiff
Diet definitely affects the flavour of the milk of all mammals. A 2008 study at Copenhagen University gave flavour capsules to nursing mothers and found that the taste made its way into their breastmilk within minutes. And dairy farmers have long known that weeds in the pasture can taint the taste of cow’s milk. It’s said that French Gruyère de Comté cheese even tastes different when it is made from the milk of cows fed on mountain grass, rather than in the valley pastures.
Feeding strawberries to cows might seem extravagant, but fruit farmers often have a lot of leftover produce that isn’t good enough to sell. A 2007 study looked at the practicalities of feeding leftover pears and peaches to dairy cattle, but it made no mention of any effect on the taste of the milk. This may be because fruit flavours don’t hang around for long – the Copenhagen breastmilk study found that non-citrus fruit flavours only affected the milk for a few hours.
You can add fruit flavour to milk indirectly though, and it isn’t always desirable. The Dairy Research Laboratory of Australia experimented in 1989 with an oat and sunflower seed supplement in cattle feed, as a way of increasing their milk’s fat content. Researchers found that the oats stimulated the bacteria in one of the cows’ stomach compartments to turn the sunflower oil into a chemical called gamma-dodec-cis-6-enolactone. This gave a noticeable raspberry flavour to the milk, and even the beef!