Burgundy beauty: The blood lime is a cross between the red finger lime and the Ellendale mandarin.
Burgundy beauty: Blood limes work well in chutneys and cordials. Photo: Wolter Peeters

Sorry, cronut and ramen burger. You guys may be the "frankenfoods" of the moment but you were far from the first on the market.

The citrus family has been getting outside-the-family frisky for centuries. Long before the "taco waffle" was conceived, Montague mandarins copulated with Capulet key limes while star-crossed oranges hit on love-lorn lemons.

Yuzu, a Japanese hybrid.
Yuzu, a Japanese hybrid.

Here are six lesser-known citrus hybrids grown in Australia. Some fruits are harder to get your mitts on than others but provided the citrus is in season, a good grocer should be able to track down your frankenfruit of choice with a bit of notice.

Yuzu

Yuzu is thought to be a mix-and-match of mandarin and Ichang papeda, a lemony Chinese fruit that looks a bit like a choko with jaundice. It's been trending in Australian restaurants for a couple of years now and Japanese cuisine for centuries.

The tangelo is a grapefruit-mandarin crossover.
Tangelo, a grapefruit-mandarin crossover.

Gerard Buchanan grows the Japanese hybrid at his Chillingham farm on the mid-north coast of NSW and supplies yuzu to hatted restaurants such as Tetsuya's whenever it's in season - usually from about mid-February to late July.

In Melbourne, Nobu uses it in a dish of soft-shell crab tempura with poached apple and jalapeno dressing and the cocktail menu at Northcote's Dojo Ramen Bar features a gimlet of West Winds gin with yuzu juice and sugar syrup.

Blood lime

Dekopons aka Sumo mandarins.
Dekopons aka Sumos. Photo: Supplied

The blood lime is a cross between the red finger lime and the Ellendale mandarin (an orange-mandarin hybrid itself). It was developed by the CSIRO as part of an effort to produce salt-resistant crops and became commercially available in Australia in 2004.

The blood lime season runs from June to September, although this can vary according to region.

The blood lime is the shape of an olive and the size of a golf ball, with deep burgundy skin. One of the small number of blood-lime producers in Australia, Tess Schmidt has about 200 trees at Jamberoo Valley Farm on the south coast of NSW. Schmidt makes a blood lime, date and ginger chutney and also recommends using them to make cordials or add flavour to a gin and tonic.

Chef Brendan Cato, who runs The Farmed Table pop-up dinners in Sydney, uses blood lime in a dish of grilled sea mullet with foraged sea plants and cucumber.  "They taste a bit like finger limes," Cato says.

Tangelo

These grapefruit-mandarin crossovers were grown in Australia primarily for the US export market. But cheap Peruvian tangelos have flooded the US in recent years and plantings of tangelos in Australia are therefore declining, says the market development manager of Citrus Australia, Andrew Harty.

"The good news for Australian consumers, however, is that farmers can now focus on the domestic market, where there is still a loyal following," Harty says.

This also results in a better tasting tangelo. "The fruit can be left longer on the tree before harvesting, resulting in richer flavour, whereas the export trade required earlier harvest of very firm fruit which could withstand the sea journey," Harty says.

Lemonade fruit

Oh, wonderful, majestic lemonade fruit, how we love thee. This Australian-developed citrus is the love-child of the lemon and orange mandarin and can be eaten straight from the tree. "It's just like an orange but a little sharper," says Kitchen by Mike's Mike McEnearney.

McEnearney has a lemonade tree at home and uses the fruit to make a hot-water drink for his children if they fall ill.

"It's less harsh than a lemon so it's easier to drink," he says.

McEnearney makes a winter-morning tonic of lemonade-fruit juice, fresh chilli and oregano he calls The Fireball. "The lemonade increases your immune system, the oregano is good for anything microbial and you've got the habanero to lift your senses. It's a really good breakfast wake up."

Their fragrance also makes them great for cooking. "When we roast chicken and vegetables at home we put hunks of lemonade fruit in the tray," he says. "Because it has a thinner skin it's less aggressive than a lemon and breaks down quite easy, lending a beautiful floral aroma to roast dishes."

Clementine

The frankenfruit with the cutest name, the tiny clementine is a hybrid of mandarin and bitter Seville orange. It's most popular throughout Europe and the Mediterranean basin, Andrew Harty from Citrus Australia says.

Clementines can be used in cakes, marmalades and sauces. Thanks to sugary and tart flavour notes, the clementine also works well with both sweet and savoury dishes.

Harty says that Australian clementines are grown mostly in the Riverland region and to a lesser extent in Western Australia, maturing from mid-May to early July. "Clementines are slowly gaining consumer acceptance, competing with Imperial mandarins for the early season window," Harty says.

Dekopon (aka Sumo)

A recent arrival to Australian shores is this orange-mandarin hybrid crafted in 1970s Japan. The dekopon has no seed, peels easily and possesses a uniquely sweet flavour. Big volumes are now harvested, mostly from Leeton in NSW, Harty says.

In a 2011 article for the Los Angeles Times, "fruit detective" David Karp declared the dekopon to be the most delicious citrus he had tasted (he claims to have tasted more than 1000 types) due to its "firm flesh that melts in the mouth, an intense sweetness balanced by refreshing acidity and a complex, lingering mandarin orange aroma".

Harty recommends looking for dekopon sold under the Sumo brand in Australia between late July and early September.