- The tonka bean is actually a seed of the cumaru tree, which is native to Central America and parts of South America. The beans are roughly three centimetres long and are shaped like an almond, but are black and wrinkled with a hard exterior and a softer interior.
- 100g of tonka beans is roughly a third of the price of the same weight in vanilla pods. To stop them drying out, keep in an airtight container.
- Tonka bean has been banned from sale as a food in the US since 1954 because it contains the chemical coumarin, which has been found to be toxic to the liver in large doses. Many US chefs have used it regardless, including Grant Achatz of Alinea, who was visited by the Food and Drug Administration (FDA) after serving it. Good news for Brits: it is unrestricted in the European Union.
The tonka bean is certainly no newcomer to the UK's dining scene. This fragrant, gnarly black legume, which shares some similarities in flavour to vanilla pods when finely grated, has been used as a flavouring for desserts by chefs for several years.
However, with vanilla prices rocketing to as much as £60 for 100g in the last year due to Madagascan plantations being hit by natural disasters, chefs have sought out alternatives – and the tonka bean neatly fits the bill.
But while it shares some of the taste profile of the aforementioned spice, tonka bean – actually a seed from the flowering South American cumaru tree – is more complex, offering notes of nutmeg, sour cherry and almond, among others.
“For me, the tonka gives a much more interesting and deep flavour than vanilla. It’s like vanilla's big brother who smokes and rides a motorbike,” says Luke Richardson, head chef at Wreckfish in Liverpool, who is currently employs tonka bean to flavour a semifreddo (semi-frozen dessert).
Chris White, chef and owner of The White Spoon in Cheltenham, is also a fan. Having first turned to tonka bean as an alternative to vanilla when prices starting rising, he now uses it to make curd to serve alongside an olive oil cake.
“In the past I have also used this very versatile ingredient in marshmallows for our petit fours board, and we’ve also served a tonka bean creme brulee in the past which was incredibly popular,” he adds.
Chris White, chef and owner of The White Spoon, Cheltenham, makes a tonka bean curd, which he serves with a dessert of olive oil cake, pistachio and rhubarb: “Depending on the dish I would normally microplane the tonka bean – to release the full flavour – and then let it infuse in milk or cream. For this dessert, I infuse milk and then make a custard, whisking in extra butter to set the curd. We began using tonka bean as an alternative to vanilla, partially due to the cost of vanilla rising but also because it adds a slightly different aroma to dishes; it has a hint of spice, almost along the lines of nutmeg. It is a strong flavour so you don’t need much, you have to find the right balance so it doesn’t overpower. Tonka bean pairs particularly well with the rhubarb in this dish as we poach it in star anise. You find that the combination of this spice and the tonka bean really complements the nuttiness of the cake.”
Luke Richardson, head chef at Wreckfish, Liverpool, uses tonka bean in a semifreddo: “First we roast the tonka beans, which helps bring out some more flavour and give it more depth of flavour. Then we semi-whip the cream, finely grate the tonka beans into the egg and sugar mix, then make a hot sabayon. We whisk the eggs and sugar over a bain marie until it at least doubles in size and goes thick and creamy. Once it's at this stage, we whisk until it cools. Once that is done, the egg mix and cream are mixed together and frozen. It's essentially vanilla ice cream – and who doesn't love more interesting vanilla ice cream, right? For me, the tonka gives a much more interesting and deep flavour than vanilla. It’s nicer than vanilla and also gives our guests an opportunity to try something different to what they would usually try.”
Ramael Scully, chef-patron at Scully St James’, London, uses tonka bean in his dessert Piura Porcelana chocolate sorbet, pistachio, tonka: “At the bottom of the bowl we put stem ginger and lightly toasted cocoa nibs, then a scoop of dairy-free chocolate sorbet, which we make in our kitchen. We then add a blueberry vinegar that has been made with red wine vinegar to make a blueberry gel. We then infuse tonka bean in a sugar syrup, which is drizzled over the rest of the ingredients. Before serving, the whole dish is lightly sprinkled with lightly toasted pistachio nuts and a light grating of tonka bean – the texture is almost like nutmeg. I find that tonka bean works so well with chocolate. It's a bit like a marzipan and gives an almond-y flavour. It pairs really well with the chocolate sorbet because of the marzipan flavour and also with the vinegar as the sorbet is rich.”