Franklin & Sons Rhubarb & Hibiscus Tonic Water
A tonic that brings its own acidity, which most do not. Rhubarb is genuinely tart and hibiscus is tarter still, so this arrives sharp rather than soft — the opposite problem to a floral tonic, and a much easier one to build around.
Quick Facts
Flavour Profile
Primary Flavours
Tasting Notes
Sharp and red-fruited on the first sip, with the hibiscus giving a cranberry-like tartness and the quinine drying an already dry finish.
Storage & Handling
Cool and sealed. Cold for service.
Usage
About 150ml over 50ml of gin, and it is one of the few tonics that genuinely suits vodka, because it supplies flavour and sharpness rather than needing them supplied. It also lengthens a rosé vermouth well.
A Tonic With Acid In It
Almost every flavoured tonic adds sweetness, softness or aroma. This one adds sourness, and that makes it behave differently from the rest of the shelf.
Rhubarb is tart because of the acids in the stalk — malic mostly, the same one that makes a green apple sharp. Hibiscus is tarter again, which is why it is drunk as a cooling infusion in hot countries and why it reads as cranberry to most British palates.
The practical upshot is that this is the tonic that fixes a sweet spirit, alongside a lemon tonic and for much the same reason.
Rhubarb Is Not the Colour
People assume the pink comes from the rhubarb, and it does not. Rhubarb juice is a pale, murky straw colour; the forced pink stalks lose most of their drama the moment they are cooked or pressed.
Hibiscus is the pigment. The flower carries anthocyanins — the same compound family behind blackcurrants and blood oranges — and a small amount colours a whole bottle. It also carries flavour with it, which is why the colour and the tartness arrive together.
What to Pour Into It
Sweetened and flavoured gins are the obvious use, and an honest one. The shelves are full of them and most are badly served by plain tonic, which brings bitterness but no acidity. This brings both.
Vodka is the surprise. Most tonics need the gin to supply character; this supplies its own, so a vodka build is a real drink rather than a diminished one.
A rosé or bianco vermouth lengthened with it makes a low-alcohol aperitif with genuine structure, which is a better use of an afternoon than most gin drinks.
Garnish
Orange peel expressed over the top, or mint clapped and dropped in. Both add aroma without adding more acid to a drink that has plenty.
Lemon and lime are the two to leave alone. The drink is already at the sharp end and citrus pushes it past pleasant into sour.
Pro Tip
Do not add citrus out of habit. Between the rhubarb and the hibiscus there is already more acid here than in any other tonic on the shelf, and a squeeze of lemon tips it from sharp into sour.
Top Tips
- It is the tonic for a sweet or floral gin. Where a plain tonic leaves those flat, this one has the acid to answer them.
- Skip the lemon. Reach for orange peel or a sprig of mint if the drink wants lifting.
- The colour is hibiscus, not rhubarb. Rhubarb in a bottle is pale; the pink is the flower doing it.
Possible Substitutions
- Fever-Tree Rhubarb & Raspberry Tonic: the parallel product, fruitier and less floral
- Indian tonic with a splash of rhubarb cordial: sweeter, and you lose the hibiscus edge
History & Context
Hibiscus has been drunk as a sharp red infusion for centuries across west Africa, the Caribbean and Mexico, where agua de jamaica is everyday rather than exotic. Rhubarb came into British drinking through the kitchen garden and the crumble dish. Neither had much to do with gin until the flavoured-tonic era went looking for things that were not citrus.
Common Questions
Does it taste of rhubarb crumble?
No — there is no sugar-and-butter sweetness to it. The rhubarb reads as tartness rather than as pudding, and the hibiscus pushes it further towards cranberry than towards dessert.
Which gin should I use?
A sweetened or flavoured one, which is where it earns its place. Those gins go flat under plain tonic because quinine is bitter rather than sour. This supplies the acid they lack.
Should I add a slice of lemon?
No. Between the rhubarb and the hibiscus there is more acid here than in any other tonic, and citrus tips it into sour. Orange peel or mint if it needs lifting.
Often Used With
Guide by Jerry Can Spirits