Why some diners loathe coriander and others love the herb

The reason people hate fresh coriander is genetic. In a paper published on the Cornell University Library website (arxiv.org/abs/1209.2096), researchers found that "a genetic variant near olfactory receptor genes influences cilantro preference". Those who dislike it perceive a soapy taste in the herb.

The researchers write, "The proportion of people who dislike cilantro varies widely by ancestry; however, it is not clear to what extent this may be explained by differences in environmental factors, such as frequency of exposure."

If you like fresh coriander, you'll know how fragile it can be. If you store it wrong, it will either turn yellow and wilt or become brown and mushy. It's best to buy only as much as you can use within two or three days. Supermarkets sell it with the roots trimmed off, but if you go to shops specialising in Southeast Asian ingredients, you'll find them intact, which is better. Take the herb home and dry the leaves. Wrap the roots - but not the stems and leaves - in barely damp paper towels and put the entire stalks in a sealed plastic bag before storing in the fridge.

A word on the roots: don't throw them away. They have a lot of flavour, and can be chopped and used in curry paste and marinades. Coriander roots are fine when cooked, but the leaves should be added to dishes at the last minute: mixed into guacamole, for instance, or used to top fresh fish after it's been steamed.