Tonka bean

• cumaru

  Portuguese

  The Brazilian name, and also the name of the timber from the same tree, which is sold as a hardwood. A search for cumaru returns decking as often as it returns the bean.

• sarrapia

  Spanish

• fève tonka

  French

• Tonkabohne

  German

  German-language baking literature uses it freely, which is worth knowing because the regulatory position in the European Union is a limit on coumarin in the finished food rather than a prohibition on the bean.

Sweet and aromatic rather than tasting of much on the tongue — the effect is almost entirely aromatic. Grated over a dish it reads as vanilla with hay and almond behind it, and it turns bitter and soapy if overdone, which happens easily.

Intense and immediately recognisable: sweet hay and new-mown grass over vanilla, with almond and a cinnamon edge. It is far stronger than its size suggests and a single grated bean will scent a room.

Black and deeply wrinkled, sometimes with a white crystalline bloom on the surface. Grated, it is a fine pale brown.

Extremely hard — grated on a fine rasp like nutmeg and never chopped. The bean does not soften in cooking and is not eaten.

• Coumarin — The dominant compound and the source of the hay-like sweetness. It is also the compound the regulation is about, and the white bloom sometimes visible on a bean is coumarin crystallised on the surface.
• Dihydrocoumarin and related compounds — Rounding the aroma towards almond and vanilla.

Use less than seems reasonable, and prefer infusing to grating. A few passes on a fine rasp will flavour a whole dessert, and the failure mode is not subtle: too much tonka turns soapy and bitter and cannot be corrected. Infusing a whole or halved bean in warm cream or milk and lifting it out gives control that grating does not, which is why professional kitchens generally do it that way. The aroma survives baking, unlike most volatile aromatics here, so it can be built into a batter rather than added at the end. Grate to order — a bean grated in advance loses the aroma that is the entire point — and store the bean itself sealed, where it will still be strongly aromatic in three years. Readers in the United States should know that it is not sold there as a food ingredient; the regulatory position is recorded on this profile rather than summarised here.

Sweet cooking almost exclusively, and European pastry above all. Tonka goes into cream and custard bases, ice creams, rice puddings, chocolate desserts, fruit compotes and baked goods, generally infused in warm cream or grated over a finished plate. It suits cream, milk, chocolate, vanilla, coffee, stone fruit, pear and pumpkin, and it sits alongside vanilla, cinnamon and cardamom rather than replacing them. A small savoury use exists in modern restaurant cooking — grated over root vegetables or into a sauce — and it remains marginal. Quantities everywhere are tiny.

• grinding — Grating is the only sensible preparation, and quantities are tiny — a few passes on a microplane flavours a whole dessert. The aroma is released immediately and a bean grated in advance loses its point.
• infusing — Infusing a whole or halved bean in warm cream or milk extracts the aroma gently and allows the bean to be removed, which gives more control than grating and is how most professional kitchens use it.
• baking — The aroma survives baking well, unlike most of the volatile aromatics in this dataset, because coumarin is comparatively stable to heat.

Scratch the surface with a thumbnail and smell it. A good bean gives an immediate strong sweet-hay aroma from a single scratch. A bean that needs to be grated before it smells of anything has been stored badly or is very old.

• Little or no aroma when the surface is scratched.
• Fuzzy grey-green growth, which is mould and means discard — distinct from the flat white coumarin bloom, which does not.
• A soft or spongy bean, which should be hard enough to resist a thumbnail.

There is no real decision to make: buy whole beans, because that is essentially all that is sold and because the whole bean is the better product on every axis that matters. It keeps for years where ground spice would be flat in months, it is grated to order in the quantity the dish needs, and — the part that matters most with this particular spice — it can be infused and lifted out, which is the only reliable way to stop. Tonka is easy to overdo and turns soapy and bitter when overdone, so a form that lets the cook remove it mid-way is worth more here than in almost any other entry in this catalogue.

• Hard, black, deeply wrinkled beans that resist a thumbnail.
• A strong sweet-hay aroma from a single scratch of the surface.
• A white crystalline bloom is a good sign, not a fault — it is crystallised coumarin.
• Bought as whole beans; ground tonka is rare and pointless.
• Sold by the bean or in very small quantities, because one bean lasts most kitchens years.

Traded on size and aroma rather than against a published international specification, with the coumarin bloom treated as a quality indicator. Availability is governed more by jurisdiction than by grade: in the United States it is not sold as a culinary spice at all.

Fabaceae

A very large rainforest tree of the Amazon basin and the Orinoco, reaching well over forty metres, bearing a fruit whose single hard seed is the spice. Cured beans are black, wrinkled, roughly the size and shape of a large prune stone, and hard enough that they are grated rather than cut.

The Amazon and Orinoco basins of northern South America, where the tree grows wild and where most beans are still gathered rather than farmed.

• VE — major producer
• BR — major producer
• NG — notable producer
• CO — notable producer

Fallen fruit collected from the forest floor and the single seed extracted from each. Collection is seasonal and dispersed across large areas.

1. Extraction and drying — Seeds removed from the fallen fruit and dried.Why: Reducing moisture before curing.
2. Curing — Traditionally soaked in rum or alcohol for a day or more, then dried again, which turns the bean black and wrinkled and brings the aroma forward.Why: The curing step is what develops the characteristic aroma; an uncured bean smells of very little.
3. Grading — Sorted by size and appearance. Beans sometimes show a white crystalline bloom on the surface.Why: The bloom is crystallised coumarin and is a sign of a strongly aromatic bean rather than a fault.

Traded on size, appearance and aroma rather than against a published international specification. The visible coumarin bloom is treated in the trade as a quality indicator.

Overwhelmingly wild-harvested from forest trees by gatherers, alongside a smaller planted supply. This makes it one of very few spices here whose production is an extractive forest activity rather than agriculture, and it links the bean trade to the same forests as the timber trade in the same species.

Wet lowland tropical forest. The tree is long-lived and slow to mature, which is why it is harvested from standing forest rather than planted for a quick return.

Long used by peoples of the Amazon and Orinoco and carried into European perfumery and confectionery from the eighteenth century, where its scent became a fixture of tobacco flavouring and fine fragrance before it was much used in food. Its modern culinary history is largely a European one, and largely recent: it became fashionable in restaurant desserts from the late twentieth century and is now an ordinary shelf item in German, French and Scandinavian baking while remaining prohibited as a food additive in the United States.

A wild-harvest forest commodity traded in modest volume, with perfumery and flavouring historically taking more of the crop than kitchens did. The same tree supplies cumaru hardwood, so the bean trade and a substantial timber trade rest on the same forests.

Recorded in South American traditional practice, and the bean has carried folk and amulet associations in its home region. Held as cultural context only. SpiceHQ holds no clinical source on tonka bean and makes no health claim about it.