Calamansi juice, sometimes called Filipino lemonade, is made from calamansi.
Calamansi is a small, sour citrus cultivated especially in the Philippines. Its juice is commonly mixed with water and sugar to make a refreshing drink similar to lemonade. The fruit’s flavor is sharply acidic, while its thin peel can contribute a fragrant, slightly sweet citrus note. In the Philippines, calamansi is also squeezed over noodles, rice porridge, seafood, meat, and dipping sauces.
The fruit has several names, including calamondin, Philippine lime, and Philippine lemon. Botanically, it is generally treated as Citrus × microcarpa and is commonly described as a hybrid involving kumquat and mandarin ancestry. That background explains why it can resemble a tiny orange or lime while tasting distinctly tart.
Calamansi is not simply another name for lemon, pomelo, or yuzu. Its round fruit is usually only about 25–35 millimeters wide, and the ripe pulp and juice can be orange-colored even when the fruit resembles a small green lime. In Filipino cooking, both the juice and the whole fruit are valued for their intense acidity.