There's a shortage of real vanilla and natural vanilla flavor. What's the difference?

In a tiny pink Philadelphia bakery called Tartes, owner Teresa Wall prepared caneles, French pastries flavored with rum and vanilla. She split a few vanilla beans in half and scraped out the tiny seeds into a pot of milk and butter. In a separate bowl she mixed eggs and flour. Once little bubbles formed in the heating milk, she poured it into the batter. The vanilla seeds speckled the mixture as they floated up.

About 75 percent of Wall's recipes call for vanilla. She uses real vanilla, which comes from an orchid and is mostly grown in Madagascar. When storms or other problems strike the island, prices spike. Sometimes she gets half a pound of beans for $30. Other times it costs her $75.

The price and supply fluctuations are a problem for people like Wall, but 99 percent of the 'vanilla' we eat globally is not the stuff Wall uses.

Instead, many food manufacturers use natural and artificial vanilla flavors in their products.

Customers, however, have started to demand real vanilla or natural flavors. Companies like Hershey's and Nestle have vowed to follow consumer preferences. The shift is helping drive innovations in flavor production, even as the line between natural and artificial blurs.

What is a vanilla flavor?

"Vanilla has about 600 individual chemicals that make this individual flavor that we use," said Daphna Havkin-Frenkel, of Bakto Flavors. Variations in vanilla flavor emerge because "we grow it in different locations, different sun, different food, different rainfall, and different curing process," Havkin-Frenkel said.

The main flavor compound that we distinctly recognize as vanilla comes from a chemical called vanillin. It's possible to isolate vanillin in a lab to make vanilla flavor.

Vanilla flavor "doesn't have any vanilla in it but it has vanillin in it, which is the same compound that happens in nature, but is manmade," Havkin-Frenkel said.

That's mostly what we eat when we get Nilla wafers or vanilla coffee creamers or any number of vanilla-flavored products.

Nadia Berenstein, a flavor historian, said vanilla flavor was first made in Germany, in the 1870s.

"Two chemical researchers figured out how to synthesize it from a compound called coniferin, which is basically found in the sap of different kinds of evergreens."

It's possible to get vanillin from vanilla beans, but you can also use other things. Over the years, scientists have produced vanillin from coal tar, wood bark, paper pulp, clove oil and fossil fuels.

Whatever the source, vanillin is vanillin. "A chemist will tell you that they're identical," Berenstein said.

Natural vs. Artificial Flavor

On a box of cookies or a carton of ice cream, though, flavor labeling gets complicated. If the vanilla flavor comes from spices, botanicals, fruits, or vegetables, it's labeled as natural vanilla flavor.

Most of our vanilla flavor today comes from petrochemicals, which has to be labeled as an artificial flavor.

Both are manufactured in a laboratory, but from different ingredients.

"Right now it's really a question of classification," Berenstein said.

When companies like Hershey's and Nestle promise to use natural flavors, they are not promising to use real vanilla.

But it turns out there's a problem there, too. Not only is there not enough vanilla bean to meet global demand, there's not enough of the so-called natural vanilla flavor to go around.

New alternatives

Companies are exploring new methods to make the flavor. A company called T. Hasegawa has been making vanilla flavor from fermented sugar.

A synthetic biology firm called Ginkgo Bioworks is in the early stages of exploring whether it can make vanilla flavor — and other flavors — by genetically modifying yeast. Ginkgo modifies the genes in yeast, taking the flavor-making mechanisms from plants and placing them in the yeast's genetic code. Feed the yeast a little sugar, and voila, it pumps out your desired flavor.

If they succeed in making vanillin this way, will it be natural?

"I like to think of it as a third category," said Ginkgo's Christina Agapakis. "I think that the distinctions that we draw between natural and artificial are themselves pretty artificial. There's a lot of nuance."

There's nuance in taste, too. Often, we just prefer whatever flavor we grew up eating. Teresa Wall, for one, said she'll keep using real vanilla.

When her caneles finally come out of the oven, she pops them out of their molds, then lets them cool before she eats one.

"Just like Oreos, I have certain ways. I always eat the top first. It's super crispy because all the vanilla seeds are sitting there at the top and then you get this really intense flavor and that's probably my favorite part."