The lighter syrup was a simple syrup with pureed cucumber that sat in the fridge for half a day, then got strained. I used powdered sugar because that’s what I had.
The darker syrup was made by pureeing and straining a cucumber, then bringing that juice to 145° while mixing in Sugar in the Raw.
A bartender warned me about heating the vegetables and giving it a “soupy” taste, and they had a point. The immersion syrup is less sweet and more watery, but has a more refreshing cucumber flavor. The heated syrup is sweeter, but doesn’t have that fresh crispness. Both are okay but neither are great.
I found some success simply mixing cucumber juice with simple syrup, sort of like a cucumber aqua fresca, but it wasn’t as… cucumbery as I wanted. It worked well enough for a cucumber gin fizz, but I think there must be a better way to extract cucumber flavor for bright refreshing punchy cucumber drinks.
The cucumber watermelon aqua fresca I made worked like a charm and did brilliantly in a tepache and tequila cocktail I made with it. Maybe cucumber is naturally mild and the deficiencies in the flavor were hidden by the presence of watermelon.
Cucumber and watermelon flavors are kind of adjacent so I can imagine the watermelon hiding the cucumber.