Finger lime green pearls - Microcitrus australasica

Here is a selection of Caviar Lime, Microcitrus or Citrus australasica in Latin, whose pulp is composed of small crunchy and juicy grains that retain their green colour when ripe. Rare and sought after, this trendy citrus tree that is coveted by the chefs of the best restaurants in the world is still little known among amateur gardeners, despite its playful appearance and compact size, which makes it well suited for container gardening. This delicate Australian citrus tree, which bears tiny leaves and thorns, produces small fragrant white flowers, followed by elongated fruits. Their skin contains a treasure trove of 'caviar', these little beads that burst in the mouth, revealing delicious tangy and aromatic flavours. This stylish and unusual citrus tree can be grown in a large container and stored in a greenhouse during winter, or planted in the ground in warm regions that are not prone to heavy frost.

The Citrus or Microcitrus australasica is also known as the 'finger lime' or Australian finger lime due to the appearance and size of its fruits, which can also resemble pickles. It is a small spiny bush belonging to the Rutaceae family, with a rather upright bushy habit. It is native to the eastern part of Australia, a mild and well-watered region. In the wild, it grows in lowland areas, in the undergrowth of humid forests.

This small tree reaches a height of 3 m and spreads to about 2m when planted in the ground, but will remain smaller when grown in a container. It is not very frost hardy and can be planted in the ground along the narrow coastal strip of the Mediterranean. Elsewhere, it should be grown in a container and stored away at the first signs of cold weather. Cultivated for its leaves and fruits, the Caviar Lime blooms in March-April. It produces pink buds that open into small white flowers with a sweet and delicious neroli fragrance, typical of citrus trees. Fruit setting is quite slow in this citrus tree, which needs time to reach maturity. The flowers give way to cylindrical, finger-like fruits, measuring 4 to 8 cm (2 to 3in) long. The skin of mature fruits is green with a slightly yellowish tinge. The fruits contain small vesicles that naturally separate from each other, like caviar, and are green, juicy, and crunchy. The fruits are harvested from October to December. They can be used to enhance both savoury and sweet dishes. The evergreen and aromatic leaves of this citrus tree measure 1cm (0.5in) to 6cm (2in) long and 3mm (0.1in) to 25mm (1in) wide. They have a very delicate aromatic flavour, used as a spice.

The Caviar Lime is grown in frost-free conditions, in a slightly acidic soil that is always moist, and in a humid atmosphere, requirements that are easier to meet when grown in a large container. Growing it in the ground is almost a specialist affair for this species, which is sensitive to temperatures below -3°C. The fruit of the Caviar Lime is a refined and sought-after delicacy, which can fetch prices of several hundred euros per kilogram. Like truffles, it should therefore be used sparingly to decorate a plate or flavour a dish. This citrus-condiment brings a pleasant tangy and aromatic note to seafood dishes such as oysters or almonds, for example. It pairs well with the flavour of scallops or thinly sliced salmon fillets prepared as carpaccio. Incorporate some crunchy beads into fruit salads or cocktails as well.

Like all Citrus trees, the Microcitrus contains essential oil pockets in its leaves, flowers, and fruits, which are often visible to the naked eye. Essential oil is extracted from them through distillation (flowers and leaves) or pressing (peel). It has anti-inflammatory and anti-rheumatic properties, as well as sedative properties, helping to combat stress and insomnia. The fragrance of the essential oil is described as fresh, citrusy, tangy, with green notes.

Most citrus trees thrive when planted in the ground in Mediterranean coastal regions, where they can enjoy the necessary year-round warmth. However, to bear fruit successfully, they must not lack water or nutrients. The Caviar Lime is not very frost hardy and starts to suffer from temperatures below -3°C. It is a self-fertile bush, meaning that a single individual is sufficient for complete pollination and fruiting.