We ran supermarket pastes through the ‘soup test’ to find out which ones have an authentic flavour and which are nothing like the real thing

• The best supermarket kimchi

Miso is a simple product that’s traditionally made by fermenting pulses (usually soya beans) with salt and koji, typically a grain (rice or barley, and more recently oats, say) inoculated with Aspergillus oryzae mould. Bar one fabulous exception, however, our supermarkets seem to have flipped the “you get what you pay for” adage on its head when it comes to miso: the least authentic and most processed products in this test were also some of the most expensive, even though they’re little more than synthetic imitations cut with thickeners, colourants, acidulants and preservatives.

I asked my friend Jono Hope from Slow Sauce, a miso and shoyu brewery in Scotland, for advice, and he told me not to taste it straight from the jar; its intense, salty flavour would ruin my palate. Instead, he advised mixing a teaspoon with warm water, then drinking it – “the soup test”.