I make rhubarb juice every year. Did not realize it was a thing. Never heard of 'shrub'.

I also make rhubarb salsa, bbq sauce, rhubarb/apple butter...rhubarb cornbread, etc..

Chop it up, cook low and slow in a saucepan. I add lots of grated ginger but just a minor Tbsp coconut palm sugar, (can always sugar up later). Strain using a fine mesh or straining bag. I add lemon juice, a bit more fresh ginger, then freeze...ice cube trays and juice containers. In some of the juice containers I add a green tea bag so as it thaws I have a ready-to--go beverage.

I harvest over a hundred pounds every year and give much of that away. One co-worker is an x-chef and took my cue and makes juice for cocktails.

Gosh, I would have thought shrubs were right up your alley, sleevendog. They're basically sweetened fruit vinegars. America's favorite soft drink before the colas came.

Oops, forgot to say that the way I learned to make any kind of fruit shrub is equal parts fruit and vinegar (needs to be fairly strong vinegar but the variety doesn't matter) and a bit less sugar. So like 2 cups each cut up fruit and vinegar and maybe 1-1/2 cups sugar. .

Heat the vinegar to just below boiling, put the fruit in a hot sterilized jar, pour vinegar over it. Leave a litle headroom in the jar, then cap tightly. Put it in a dark place once ht vinegar cools and let it stand at least 24 hours, as long as 3 or 4 weeks.

Strain the liquid off through cheesecloth or a coffee filter (may need to do it more than once), then put the liquid into a saucepan with the sugar and boil and stir till all the sugar is dissolved. Put into a hot sterilized container and refrigerate once it's cool enough.

To serve, put a tablespoon or two of the vinegar concentrate into a glass and fill it up with water or sparkling water.

ETA For safety it's important to have a strong, acidic vinegar for the first stage.

And then there is switchel....

Ah ha, I know what that is. Nope, don't like it. Basically a simple syrup with fresh fruit. A bit of mild fermentation. I do like the freshness and additions of herbs/spice. A cocktail making friend uses a cold steep, no heat. I should give him some rhubarb.

I take my coffee black and my cold brew iced green tea with ginger and lemon. No sugar. My rhubarb juice is more of a switchel. Maple syrup or coconut palm but just a pinch, with seltzer. Most times just over ice or with cold brew tea. Or sip as it thaws.

Would be fun for a party but I just make my usual and have a dilute honey/maple water on the side.

Yes, I must admit that while I've made it, I don't think it's worth the effort, myself. But then I don't grow fruit here, only vegetables because my space is so limited, so I never have lots of fruit to use up.

I seem to have found a cheater recipe - completely by accident. As in cooked. Simmer the first 4 ingredients for twenty minutes. Add the vinegar. Let cool and strain.

1 pound rhubarb•1/2 cup honey•1/2 cup sugar•1/4 cup water•1 cup AC vinegar

It’s pretty good in water. I will try out the juice and look up switchell.

Let us know how you like it.