One soda siphon is enough for about 4 highball glasses
Fill a highball glass to the top with ice cubes
Place 10 bar spoons of sea buckthorn jam into a soda siphon
Pour in 120 ml of tarragon syrup and 800 ml of club soda
Close the soda siphon and froth 3-4 times
Pour the cocktail from the soda siphon into the highball glass