Question re: Cassis beverage on KLM
 

A few years back, I flew LAX to Amsterdam on KLM in coach. They served the most delicious soda-type drink, called Cassis, if I'm not mistaken; a sparkling red currant beverage. I've not been able to find it anywhere in the US and it wasn't offered on any other airlines I've flown since. Does anyone know anything about this heavenly elixir? Many thanks.

Creme de Cassis
 

It's a liquer made from black currants (cassis) and, as you discovered, is delicious as an apertif - with white wine or champagne it's Kir, and goes down very smoothly.
You'll find it in most liquor stores, I think even Trader Joe's carries it.

Cassis is a very popular soft-drink here in the Netherlands. I am not sure it is sold in other countries.

If it's the one I think it is, one of the most popular types is made by Spa (actually Belgian, but a mineral water manufacturer) and flavoured with blackcurrant. Unlike 'cassis' or 'creme de cassis' in other countries, it's a soft drink.

Have a look at:
http://www.popsoda.com/herocassis.html

Thank you for the responses. I found two place that sell it and have ordered a bunch of cans. Can't wait!

More specifically, with Champagne it's a Kir Royale and with white wine it is a Kir. It was my aperitif of choice when I lived in France.