Australia is almost the size of Europe, spanning pretty much every climate zone and boasting a mind-boggling diversity of plants. Yet from this botanical treasure trove of more than 30,000 species, the Aussies have only provided the world with a single major crop: the macadamia. With the revival of traditional Aboriginal cuisine, however, some incredible new flavours are beginning to get the attention they deserve.
As a “bush tucker” geek, I have tried my fair share, and so far my favourite is the caviar lime (Citrus australasica). As delicious as it is quirky looking, like something straight out of Charlie and The Chocolate Factory, the fruit is almost impossible to buy in the UK. Just as well then that they are widely available as houseplants, capable of fruiting in any brightly lit living room.
Originating from the subtropical rainforest on the border of New South Wales and Queensland, these long, cylindrical fruit look a bit like gherkins on the outside. Not very appealing. Slice one open, however, and the pulp spills out like shiny bubbles of caviar in vibrant shades of emerald green, pale yellow, even bright pink and deep reds. The juice is trapped in each of these tiny, jewel-like bubbles and is only released when bitten into, creating a bright spritz of intense lime flavour with a fragrant hint of mandarin. Imagine pomegranate grains, only far tinier, with an intense citrus tang and coming in the colours of the rainbow.
Their recent introduction into commercial production has seen them enthusiastically taken up by top chefs all over the world who sprinkle the citrus-flavoured grains over salads and muddle them through martinis. Because of their brilliant colour, acidity and resemblance to caviar, they are spooned over oysters and served with smoked salmon or even rolled around sushi instead of flying-fish roe. I find they work well in salads and fresh sauces. They are really just limes in far cooler looking and more versatile packaging.
The plants are now increasingly available online from a range of independent nurseries at a similar price to conventional citrus and can be grown in almost the same way. A bright spot indoors, away from radiators but close to a window, would make the perfect habitat. Like all citrus plants, they benefit from a dose of liquid feed during the spring and summer, as well as well-drained potting mix that is on the acid side (any commercial citrus compost will do fine). Just ensure the plant dries out slightly between waterings, as they hate having their roots sit in cold, sodden compost.
Regular limes cost less than 50p in a supermarket, yet the fruit of quirky, tasty caviar limes are essentially unbuyable – and I know which I’d pick to grow at home.
Email James at james.wong@observer.co.uk or follow him on Twitter @Botanygeek
