Black pearl finger lime (true caviar) - Microcitrus australasica

The Caviar Lime, Microcitrus or Citrus australasica in Latin, also exists in a black-seeded version that will surprise on the plate as much as in the mouth. Rare and sought after, this trendy citrus fruit that top Chefs from around the world are clamoring for is still little known among amateur gardeners, despite its playful appearance and compact growth, well suited to pot cultivation. This small Australian lemon tree produces small white or pink, fragrant flowers, followed by elongated fruits. Under their fragrant skin lies the 'caviar', small translucent beads that reveal delicious tangy and aromatic flavors. This chic and unusual citrus fruit will be cultivated in a large container to be stored in a greenhouse during winter, or in open ground in warm regions that are spared from severe frosts.

The Citrus or Microcitrus australasica is also known as the 'finger lime' or 'Australian finger lime' due to the appearance of the size of its fruits, which can also resemble pickles.

It is a small thorny bush from the Rutaceae family, with a rather upright bushy habit. It is native to the east of Australia, a mild and highly rainy region. In nature, it grows in plain areas, in the undergrowth of humid forests. The natural variability of this species has allowed for the selection of different varieties of different colours, offered in cultivation, among which some have been named and registered.

This small tree reaches a height of 3 m (10ft) and spreads over approximately 2 m (7ft) in open ground, but will remain smaller when grown in a pot. Not very hardy, it can be planted in open ground in a narrow strip along the Mediterranean coast. Elsewhere, it will be cultivated in a pot and stored as soon as the first frosts arrive. Cultivated for its leaves and fruits, the Caviar Lime blooms in March-April. It produces pink buds that open into small white to pink flowers, with a sweet and gourmand neroli fragrance, characteristic of Citrus. The fruiting process is quite slow in this citrus fruit, which needs time to reach maturity. The flowers give way to cylindrical, finger-shaped fruits, measuring 4 to 8 cm (2 to 3in) long. The skin of the mature fruits can have various shades, from green to almost black, passing through red, purple, and brown. They contain small, juicy, and crunchy vesicles that naturally detach from each other like caviar. The fruits are harvested from October to December. They enhance both savory and sweet dishes. The evergreen and aromatic leaves of this citrus fruit measure 1 cm (0in) to 6 cm (2in) long and 3 mm (0in) to 25 mm (1in) wide. They have a very delicate aromatic flavor, used as a spice.

The Citrus australasica is cultivated frost-free, in a slightly acidic, always moist soil, and in a humid atmosphere, requirements that are easier to meet in a large pot. Cultivating it in open ground is almost a specialist affair for this species, which is sensitive to temperatures below -3°C (26.6°F). The Caviar Lime fruit is a refined and sought-after delicacy, with prices reaching several hundred euros per kilogram. Just like truffles, it should be used sparingly to decorate a plate or flavor a dish. This citrus-condiment brings a pleasant tangy and aromatic note to seafood such as oysters or almonds, for example. It pairs well with the flavor of scallops or salmon fillets prepared as carpaccio. Also incorporate some crunchy beads into fruit salads or cocktails.

Like all Citrus, the Microcitrus contains essential oil pouches in its leaves, flowers, and fruits, often visible to the naked eye, from which essential oil with anti-inflammatory and anti-rheumatic properties, as well as sedative properties, can be extracted by distillation (flowers and leaves) or by pressing (zest), allowing to fight against stress and insomnia. The fragrance of the essential oil is described as fresh, citrusy, tangy, with green notes.

Most citrus fruits thrive in open ground in Mediterranean coastal regions, where they find the necessary year-round warmth. But to bear fruit well, they must not lack water or nutrients. Not very hardy, the Caviar Lime begins to suffer from cold temperatures below -3°C (26.6°F). It is a self-fertile shrub, which means that a single individual is sufficient for complete pollination and fruiting.