Quick answer: for one litre of rum, count 3 to 5 Bourbon vanilla beans, split lengthwise and left whole in the bottle. The low end of the range is for a large bean, the high end for a small one. An S grade is enough: in alcohol, nobody looks at the bean, only its matter counts. Sweeten to taste, seal, store away from light, then wait. A few weeks for a first taste, a few months for a truly rounded bottle.
A bottle, a few beans, and time
Infused rum is the simplest preparation you can make with a vanilla bean. No cooking, no technique: a bottle, a spirit, split beans, and patience. The alcohol works cold, slowly, and draws from the bean what a hot custard has no time to take.
Our family grows and cures this vanilla in the SAVA region, in north-eastern Madagascar. There, a split bean in a bottle is not a recipe, it is a household gesture: you set it aside, let it work, and bring it back out for an occasion.
Which bean to choose
An S grade is enough
Our Bourbon vanilla beans, Vanilla planifolia, are sorted into four grades by length, from S, 10 to 12 cm, to XL, 19 to 20 cm. It is the same vanilla, from the same harvest; only the matter per bean changes: a 19 cm bean carries twice as many seeds as an 11 cm bean.
For an infused rum, the beauty of the bean does not come into it: it will spend months at the bottom of a bottle. On our Bourbon vanilla beans page, grade S is described for what it is: the bean for infusing, for slipping into a vanilla sugar or an infused rum, the cheapest per unit. You simply count one or two more within the range; with Ls or XLs, stay at the low end.
What you are paying for in each grade is explained in what a vanilla bean really costs, and what the sorting means in vanilla grades.
A split bean infuses faster
A whole, closed bean gives little to the alcohol: its skin holds it back. Split from end to end, it exposes its caviar and the inside of its flesh, and the infusion starts right away. No need to scrape out the seeds separately: the open bean works with everything it contains.
The bean should be supple, brown, fragrant up close. A bean that has dried out will give less, but will not spoil anything: simply add one more. Our advice for keeping it in good condition is in storing and preparing beans.
The method, bean by bean
- Choose the bottle. A bottle or glass jar, clean and dry, that closes well.
- Choose the rum. A rum you already enjoy neat. A white rum leaves all the room for the vanilla; an amber one brings its own woody notes, and the vanilla will be more discreet in it.
- Split. Lay the bean flat, prick the tip of the knife near one end and split it lengthwise, without cutting it in two. Do not rinse the bean: you would wash off its most fragrant part.
- Bottle it. Slip in the split beans, 3 to 5 per litre. They must stay under the level of the alcohol: a bean that sticks out dries and gives nothing. If the bottle is short, cut the bean into two pieces.
- Sweeten to taste. Sugar is optional. Some add none, others add cane sugar, powdered or as syrup. Go gently, you can always add more, never take it out: it is best to sweeten after a first taste.
- Seal and store. Cap tightly closed, bottle in a closed cupboard, at room temperature, away from light.
- Wait, and turn. From time to time, gently turn the bottle to bring the alcohol and the bean back into contact. No need to shake it.
- Taste. A spoonful after a few weeks, then again later. It is you who decides when the bottle is ready.
How long: weeks, then months
There is no right date, there is a taste you are waiting for. In the first weeks, the rum takes on the colour and smell of the vanilla, but the two stay side by side: the alcohol on one side, the vanilla on the other. Over months, they merge. The rum rounds out, the vanilla moves from aroma to flavour, and length on the palate settles in. The longer, the rounder.
Taste rather than count, without opening the bottle every day: each opening lets a share of the aromas escape. Once you like the rum, there are two paths: leave the beans in, and they will keep giving gently, or remove them and decant into a clean bottle to keep it at that point.
If the result seems light, the cause is almost always time, not quantity: wait before adding a bean. Our benchmarks for creams, ice creams and drinks are gathered in our dosage guide.
Pairings: pineapple, cinnamon, wild pepper
Vanilla alone makes a complete infused rum. But it likes company, as long as it stays the leading voice.
- Pineapple. Pieces of fresh, ripe fruit, with the beans: the fruit's sugar and acidity answer the roundness of the vanilla. With fresh fruit, you can taste sooner.
- Cinnamon. A stick of Madagascar cinnamon, whole, never ground, which would cloud the rum. Our family grows it in Vangaindrano, in the south-east of the island. Its woody warmth blends effortlessly with vanilla.
- Wild pepper. A few whole berries of Voatsiperifery wild pepper, for a touch of citrus and wood on the finish. A small pinch is enough: pepper quickly takes over.
For a more spiced rum, where vanilla becomes one voice among others, read our page on Madagascar spiced punch.
Storing the bottle, and the frost
Once ready, infused rum keeps like any spirit: bottle well sealed, away from light, at room temperature. The removed beans are not wasted: air-dried, they flavour a jar of sugar.
A word on frost. It happens that a bean, in its tube or pouch, becomes covered in a bright white veil along its ridges. This is not mould: it is crystallised vanillin, vanilla's main aromatic compound, risen to the surface. A sign of richness, and for an infused rum a bonus: these crystals dissolve in the alcohol. Never rinse a frosted bean. To tell frost apart from real mould, read frost on a vanilla bean.
Frequently asked questions
Should you scrape the caviar before putting the bean in the rum?
No. Split the bean and put it in whole: in alcohol, the open bean gives its seeds and its flesh without needing to be separated. Scraping the caviar out separately is the pastry method, explained in vanilla caviar.
Can you use a bean already infused in a custard?
Yes, as a second life. Rinsed and dried, a bean that has already infused a milk still gives something, but noticeably less. For a bottle you will wait months for, we prefer fresh beans.
Which vanilla for an infused rum, Bourbon or Pompona?
Bourbon is the vanilla for infused rum as we make it at home. Pompona, whose beans run 20 to 25 cm, gives a different reading. Bourbon remains the safe benchmark.
Our beans, and everything that comes from them, are gathered in the Bourbon vanilla collection. The rest of our pages are kept in the Wiki.
Alcohol abuse is dangerous for your health. Please drink responsibly.
