Indian sherbets are sweet concentrates of flowers, fruits and roots, diluted with cold water at the moment of drinking. The syrup is a preservation format rather than a convenience.
Sugar holds volatile aromatics in place
Rose petals, vetiver root and unripe mango carry aromatic compounds that dissipate quickly in water and disappear entirely when heated hard.
A dense sugar syrup slows their escape, both by reducing the free water they would move through and by raising the viscosity of the liquid holding them.
The same concentration that preserves the aroma also makes the syrup resistant to spoilage, so a bottle keeps for months rather than days.
Extraction is usually cold or gentle
Delicate botanicals are steeped rather than boiled, since sustained heat drives off exactly the top notes the drink is made for.
Traditional practice for some ingredients involves distilling an aromatic water first, then combining it with syrup, which separates the extraction from the sweetening entirely.
Roots and seeds tolerate more heat, so preparations built on those can be simmered in a way a flower-based one cannot.
Dilution is where the drink is actually made
The concentrate is designed to be cut heavily, and the ratio determines whether the result reads as refreshing or cloying.
Cold water is the usual medium, though milk is used for some, which changes the aroma noticeably since fat holds and releases different compounds than water does.
Salt appears in several traditional versions, where a small amount sharpens the fruit and keeps a sweet drink from feeling heavy in hot weather.
Seasonality is the reason the format exists
Roses, green mangoes and many of the fruits used are available for a short window, and a syrup converts a brief harvest into a supply that lasts.
Households traditionally made these concentrates during the season and drew on them through the year, which is why recipes are written in bottle quantities.
The drinks are also tied to hot weather, so the syrups made in one season are drawn down hardest in the next, matching supply to when they are wanted.
Buying and using them abroad
Indian groceries carry bottled concentrates, and reading the label is worthwhile because some are built on real botanical extracts and others on flavoring and color.
The strong ones dilute much further than the instructions suggest, so a bottle goes considerably further than its size implies.
They also work outside their original use, adding aromatic sweetness to sparkling water, yogurt drinks and desserts where a plain syrup would contribute sweetness alone.