Shortly after we arrived in Offenburg, I got some gourmet hot chocolate that boasted the flavor of “Tonkabohnen”, tonka beans. Never having heard of this spice, I immediately did some research. Tonka beans are a South American legume with similar chemical properties to vanilla. They also contain a naturally occurring substance called coumarin (not to be confused with Coumadin, which is a blood thinning medication derived from but not chemically equivalent to coumarin- see the Atlantic article linked below for more on that). In very high doses, coumarin can potentially cause liver damage. The studies that were done fed large amounts of tonka beans, and in some cases liquid extract from the beans, to rats and dogs. At concentrations of about the same amount as a human eating 30 beans, liver toxicity occurred in rats. In animals fed high doses of the extract, heart paralysis sometimes occurred. The US FDA looked at the test results and, maybe understandably, said “No way!”, banning tonka in particular and all coumarin containing foods in general. After this edict went into effect, it was discovered that many foods, and especially many spices, contain coumarin. Commonly eaten things like certain kinds of licorice, cassia cinnamon, lavender, etc. contain this compound, which is credited with a strong scent combining the aroma of hay and vanilla. In fact, as the law has not been changed since 1954, cassia cinnamon is probably technically illegal in the US. However, the amounts necessary to achieve toxicity are unreasonably high for a spice used much like nutmeg. No one sits and wolfs down 30 nutmeg seeds, after all (and if they did, they would discover that nutmeg, too, is toxic at high doses). The rest of the world looked a bit longer at the results and shrugged. Tonka beans are perfectly legal and considered harmless pretty much everywhere except the US. As I continued to research, I discovered that the French are rumored to be particularly fond of the nuanced flavor for both desserts and savory dishes. In South America they are used habitually to make beverages- actually sometimes containing doses similar to the 30 bean toxic limit, but apparently ill effects are not know. This raises the possibility that the tests done with animals may not accurately transfer into human physiology. Many, if not most, commonly eaten substances can be harmful in extreme doses, so I began to get the impression that the US ban might be over-reacting a bit. The Atlantic wrote a nice overview article about it a few years ago. In the end, I was satisfied that tonka beans are perfectly safe when used as a normal spice and not ingested, for instance, as a very expensive meal all on their own.
SO, bolstered by research and intellectually curious, I decided that this was something I needed to seek out. However, despite the fact that all accounts indicated it should be locally available, I couldn’t find any! I looked at our local supermarkets. I looked at the markets in France. I checked out the spice vendors at the street market. But, no one had tonka. I could have mail ordered it, but that seemed like cheating. Eventually, I just sort of forgot about the project and went on to other things.
Then, this week while shopping at Edeka, I noticed they had changed one of their spice brands. The new brand stocks tonka beans! It was an easy decision and I came home carrying a small tin with what looked like six large desiccated raisins. I was amused to note that the tin had an inner cup to decrease the amount of space that the beans rattled around. You immediately got the sense that this was a special spice– like when you buy saffron in those cute mini jars, or vanilla beans packed in their own little test tube. The beans themselves were remarkable only in that they are covered in a dusting of tiny crystals- natural vanillin accumulated from the drying process.
I admit it, I am the sort of person who gets totally excited about new ingredients, so I didn’t wait too long to open the package and get a whiff. Nice. Vanilla, a little spicier, sort of nutty and faintly sweet. I didn’t get the whole “fresh cut hay” thing people talk about, but it definitely intrigued me. Next step was to set about deciding how to use it. I researched online. Unsurprisingly, the results in English were relatively few. In fact, many of them turned out to be by expats like me posting about their own culinary adventures! I eventually settled on a recipe for another French Favorite of mine, Canelés/Cannelés, a pastry that required me to seek out bees wax and a special mold a couple years back.
The first step was grating the 1 bean necessary for the double recipe of pastries (be reassured US friends and family, this is a very small and even by US standards quite safe amount). The beans are dauntingly hard, so I worried that they might be difficult to grate, but I pulled out my microplane and was pleasantly surprised at how simple it was. The aroma was not as strong as I expected, but it was enticing, and as the evening wore on, I realized that it stayed with me. The flavor, too, was less intense than I thought, but hours later I found myself still noting the lingering bright tones. It was very much like the first time I sampled really good Vietnamese Cassia from Penzey’s. This may make sense since as I mentioned before, cassia also has a high percentage of coumarin. The flavor of the grated bean was akin to the scent, though a step spicier- like a little electric spark on the tongue. Vanilla, cinnamon, grassy tones and a smidgen of sweetness.
Cannelés are a two day process because the batter should rest overnight in the refrigerator. One of the reason I chose them as a starter recipe is that the procedure starts with the spice steeping in warm milk and then allows all the flavors to mingle over a long rest before cooking. I figured this would give me a good chance at capturing the complexity of the tonka bean’s layers of flavor. So, how did it turn out? Delicious, actually! I specifically didn’t use any other spices in the recipe so I could best evaluate the newness. If I didn’t know what I had used, I would think: vanilla, cinnamon, and maybe a pinch of mace and just a hint of a berry-like fruitiness. It blooms a bit on the tongue and leaves a subtle cool after sensation, almost, but not quite, metalic. The scent is what really stays, and I understand completely why it is a common ingredient in perfumes. It isn’t shocking or revolutionary, really. But, I do like it. As long as they are available, I will probably just add tonka beans into my general spice array.
Editor Note: I had remembered this article from a while back and had to look it up to make sure I was remembering properly. Yes indeed, it seems the EU is much more concerned with regulating the use of cinnamon in cinnamon rolls than worrying about folks purchasing small amounts of tonka beans: http://www.latinpost.com/articles/5850/20140113/cinnamongate-eu-danish-cinnamon-rolls-spicy-need-less-twists.htm