⭐ This is what the 19th-century bar actually sweetened with, and it is why Jerry Thomas keeps calling for “gum syrup” instead of simple syrup.
Gomme sirop is a rich syrup with gum arabic dissolved into it — a natural resin tapped from acacia trees, food-safe, essentially flavourless, and an excellent emulsifier and texturiser. It was the standard through most of the 1800s, and it is the correct sweetener for the Improved Whiskey Cocktail and most of Thomas’s book.
What it adds is weight and cling, not sweetness. A gomme-sweetened drink has a silky, faintly viscous body that plain syrup cannot manage at the same sugar level — and, the part that matters in a strong drink, it rounds off the burn of the spirit without adding more sugar to do it.
🔴 It is slow, and that is the whole reason bars stopped. Gum arabic does not want to dissolve. Rushing it gives a gritty, cloudy syrup. Plan on leaving it overnight and doing something else.
Ingredients
- Step 1 — the gum solution
- 100 g powdered gum arabic (acacia gum)
- 100 g warm water
- Step 2 — the syrup
- 2 cups sugar
- 1 cup water
- 1/2 oz vodka, optional, for keeping
Directions
- Hydrate the gum first. Whisk the powdered gum arabic into an equal weight of warm water. It will look lumpy and wrong and refuse to combine. That is normal.
- Cover it and leave it overnight, or up to 24 hours, stirring whenever you pass. It slowly becomes a thick, translucent, honey-like liquid. ⚠ Do not try to shortcut this with heat or a blender — you get foam and grit instead of a solution.
- Make a 2:1 rich syrup: heat the water, add the sugar, stir until it runs clear. Do not boil hard.
- Off the heat, stir the hydrated gum into the hot syrup — roughly a fifth of the syrup’s volume. Stir until completely uniform.
- Skim any foam off the top. There will be some.
- Cool completely. It thickens as it cools.
- Bottle, label, refrigerate.
Notes
Ratios. The common bar proportion is about 3 parts sugar : 2 parts water : ½ part liquid gum arabic, or more simply: make a 2:1 rich syrup and add hydrated gum at around 20% of its volume. Both land in the same place.
⚠ Foam and haze are the two failure modes. Both come from agitating the gum too hard or too early. Slow hydration, gentle stirring, and skimming at the end are the whole technique.
Use it the same way as rich syrup — around ¼ oz in a 2 oz drink. It is a 2:1 base, so it is sweeter per volume than 1:1 simple.
Where it earns the effort: spirit-forward stirred drinks, and anything historical. An Old Fashioned or a Manhattan made with gomme has a body that people notice and cannot place. It is also a genuine emulsifier, so it helps hold citrus drinks together in a way glycerine does not.
Keeps 3–4 weeks refrigerated. Half an ounce of vodka extends that. ⚠ Cloudiness that was not there when you bottled it means it has turned — throw it out.
Sourcing: powdered gum arabic (acacia gum) is sold as a baking and brewing ingredient and is inexpensive. Buy powder, not the whole tears, unless you enjoy grinding resin.
Gomme vs glycerine: glycerine is ten seconds’ work and gives smoothness. Gomme is an overnight job and gives smoothness plus structure plus emulsification. If you only ever make one, make the glycerine version — but make this one once, for a Manhattan, to find out what the 19th century was on about.
Deep dive, Vol 3: brewing.fubsypoly.com/mixed-drinks/old-fashioned/