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The spice series: tonka and vanilla

Categories: Expert guidance

In this series, food writer and regular Borough blogger Ed Smith takes an in-depth look at the many spices available at the Market. This month: tonka beans and vanilla pods

It seems appropriate, for the final instalment of this series, to finish with something sweet. So we head to central America for two spices that add a heady and honeyed fragrance to the ingredients they’re mixed with: vanilla pods and tonka beans.

Everyone knows and (I think?) loves the former. The latter is currently my favourite flavouring, so if it’s not something you’re familiar with yet, I hope you pick a pot of them up from the Market next time you’re down.

Vanilla
There’s vanilla flavouring (sometimes known as ‘essence’)—the synthetically produced solution found in cheap ice creams, drinks, probably some perfumes too. And then there’s real vanilla, which is technically chemically identical, but rich, rounded, musky and wonderfully sweet.

The one we’re interested in is, of course, the real one: the seed pod of the vanilla orchid, a species originally found in Mexico, though now also grown along the tropics in the Indian Ocean (Madagascar, Réunion), South Pacific (Tahiti), and Indonesia. Most often we will be tasting the Madagascan variety. Though fat, juicy, fruity Tahitian pods are prized, and the original Mexican pods rich and earthy (and expensive).

Interestingly, vanilla pods are almost completely without flavour when freshly removed from the orchid. To reach the blackened, sticky and sweet state we know them as, they need to be ‘cured’.

The ‘curing’ process has four stages: dipping in hot water to stop the vegetative growth of the pod; seven to 10 days of sweating and fermenting in high heat and humidity; a further 6 months, when the pods are kept in sealed boxes to ‘condition’ and develop the characteristic fragrance; and then a final process of grading for quality.

Even when we ignore air miles, storage, distribution and sales, this, then, is a spice that requires a lot of work. Which goes some way to explain why vanilla is second only to saffron in expense—the other main reason being that demand outstrips supply.

Vanilla finally arrives in our store cupboards in a number of possible states: the whole pod; powder (ground pods, sometimes mixed with sugar), or as an extract in lightly alcoholic solution.

The extract is a pretty good and cost-efficient way of having this spice almost always to hand, and lasts a long time to boot.

Vanilla pods are fairly long lasting, too, provided they’re kept in an air tight container and so don’t dry out; it’s why pods are generally sold solo and vac packed and or kept in a tightly lidded tube.

You will almost certainly have read before that fresh vanilla pods should be split in half lengthways with a sharp knife, and their seeds removed by scraping the blunt edge of that knife down the pod. The seeds can be mixed directly into butter, flour and sugar. Or, along with the pods, they are often added to a liquid, so that their flavour can be infused into it.

Don’t throw the pods away if your recipe only requires the seeds—pop the pod in your sugar pot as over time, this will add vanilla fragrance to all of your sweet things.

All is not lost if you find a dried pod in your cupboard: put it in a food processor or spice grinder with 150g of sugar and blitz until the pod is well and truly powdered. This is pretty much how they make vanilla powder.

Tonka bean
Tonka beans are the seeds of a flowering tree known as ‘cumaru’ (Dipteryx odorata), which is native to central America and northern South America, and particularly prevalent in Venezuela, Brazil and Nicaragua. The beans themselves tend to be about three centimetres long and shaped like an elongated, squashed almond. They’re black, wrinkled, shiny and fairly hard on the outside, yet contain a smooth and brown hardened paste inside. And they’re incredibly fragrant.

Though often used as a replacement for vanilla, there are many other smells that spring to mind when you open a pot containing these beans (and even more when you cut open the bean itself). I get almond, nutmeg, the high notes of liquorice, cherry, cinnamon, caramel and dark honey too. It’s totally recognisable, and yet it’s unique and unplaceable.

The familiarity, apparently, is due to the chemical compound within it, ‘coumarin’, which for almost a century has been used within perfumes, wood polish, pipe tobaccos and fabric conditioner. So if you do feel as though you’ve smelt tonka beans before, despite never having set eyes on them, there’s every chance it’s because it evokes memories of your grandmother’s laundry pile. That is, unless you’re a keen forager: high levels of coumarin are also found in woodruff and meadowsweet.

The beans are best kept in an air tight container, I think because that helps prevent them from drying out too much and thereby letting go of too many of the wonderful flavour compounds. Spice Mountain sells the beans in screw top jars, which is a good enough storage container.

Generally, it seems tonka beans are best grated finely, like nutmeg, and infused into liquids such as milk, cream, custard or sugar syrups.

Technically, too much tonka can be toxic (it’s outlawed in the USA), but the quantities of the spice required to reach danger levels is well beyond normal consumption. That said, too much tonka can be acrid, so don’t grate too zealously, or infuse for an indefinite period.

Culinary uses
Classic dishes that major on vanilla tend to be custard based: ice cream, creme brulées, creme caramel, vanilla custard tarts, and ice cream, of course.

The flavouring (and all of the aforementioned things) goes famously well with two particular genres of ingredients: spices and fruits.

On the spice front, it matches things like nutmeg, clove, cardamom, ginger and anise—and by extension, anything they go well with. These spices tend to be combined in custards, cakes and biscuits…  and in turn with fruits such as apples, blackberries, rhubarb, quince and figs.

Combinations that are less immediately obvious, but to which we are well accustomed, are those such as vanilla and chocolate and (tried and tested since the Aztecs), vanilla and coffee (think of affogato, an espresso poured over a ball of ice cream) and vanilla and hazelnut (err, the brown and white striped, chocolate, hazelnut and vanilla spread that you see on the continent).

And then there are the matches that might surprise: shellfish and white fish are fans of a hit of vanilla, particularly when there’s a buttery beurre blanc sauce, and perhaps a fine oaked white Burgundy alongside, which is characteristically labelled as vanilla-like. Add a spot of anise to the mix, through liquorice, tarragon or fennel, and you’re in a very good place.

Though far more complex a flavour, a decent starting point for using tonka beans when you cook is to think of it as a replacement for vanilla: both in terms of style and flavour pairings, what goes with vanilla, tends to go with tonka. So, custards, tarts and cakes, either solely tonka flavoured, or matched with stone fruits (apricots in particular), apples and pears, chocolate, coffee. It’s even a good match with the likes of scallops and sea bass (in moderation).

Being less sweet than vanilla, though, means you might try it with a few more savoury items: grated in moderation into a beef stew instead of nutmeg, for example, or similarly into a swede, carrot or jerusalem artichoke purée or soup.

Market spice heroes
It’s hard to overlook Bread Ahead’s famous vanilla custard doughnuts, but on this occasion we will, and shall turn instead to Greedy Goat’s classic Billy Vanilly ice cream. The goat’s milk base adds a tang that’s not there in a plain vanilla cow’s milk version and the rounded sweetness of vanilla bounces off that tang very pleasingly indeed.

Specific recipes to look out for
I’ve drawn something of a blank in my cookbooks for uses of tonka beans, though I imagine there are some decent recipes out there. On the vanilla front, though, consider:

—Itamar Srulovich and Sarit Packer’s plum and vanilla iced tea in their book Honey & Co: The Cookbook.

—A celebration of a classic vanilla custard in the form of iles flottantes, in Blanche Vaughan’s Egg.

—Rick Stein’s Thessalonian baked filo pastries with vanilla cream, in his Long Weekends book.

—A clutch of lovely ideas for using vanilla in your preserves, thanks to Kylee Newton’s The Modern Preserver—things like rhubarb and vanilla cordial, and vanilla and peach jam.

But you want to cook with tonka beans, don’t you? In which case, have a go at my tonka bean and honey panna cotta with vanilla poached pears.