Sugar-free chocolate: why it doesn’t work (yet)

Stevia plant
Stevia plant

I’m interrupting your regularly scheduled gianduja blog series to bring you this important public service announcement.

Apparently a UK firm has developed a way to eliminate the bitter aftertaste of chocolate sweetened with stevia. This is very cool news for chocolate lovers who can’t (or won’t) consume sugar.

To date, sugar-avoiders have had very few options when it came to chocolate. Most of the sugar-free chocolate on the market relies on sugar alcohols (erythritol, xylitol, mannitol, etc.) for its sweetness. Sugar alcohols are notorious for causing GI distress in some people, making chocolates sweetened with them not worth the discomfort for those affected. But stevia, an all-natural calorie free sweetener, doesn’t cause GI issues and doesn’t affect blood glucose levels the way some artificial sweeteners are purported to do.

That said, stevia tastes terrible in chocolate. I’ve tried adding it to unsweetened chocolate several times, and on a good day the results taste like aluminum.

Which is unfortunate, because I really WANTED to like stevia-sweetened chocolate. Not because I worry about my sugar intake, but because I grew up eating a lot of stevia (health-obsessed family + diabetic parent = lots of weird food in the house) and have grown to appreciate its gentler, lingering sweetness in foods like oatmeal or plain yogurt. It’s the perfect sweetener for coffee. So why not chocolate?

It turns out, the answer to that question is complicated. One of the interesting things I’ve learned while working for a local small-batch chocolate maker is that sugar does more for chocolate than just sweeten it. It also affects chocolate’s viscosity, texture and flavor intensity.

Sugar’s effect on chocolate’s viscosity:

Adding sugar to chocolate reduces the chocolate’s relative cocoa butter content, which means adding sugar will thicken your chocolate. Cocoa nibs are about 50% cocoa butter, and most chocolate makers add additional cocoa butter to facilitate molding and enhance texture. But add 30% sugar to that chocolate and your total cocoa butter percentage will fall significantly. This leads to thicker chocolate that many chocolatiers may find unsuitable for enrobing confections.

Sugar’s effect on chocolate’s texture:

Conching machine or melangeur
Photo credit: Mark Chamberlain via Rochester City Newspaper

Also, part of the art of making chocolate is figuring out the right time to add the sugar. The cocoa beans are ground by granite rollers in a melangeur for several days, and sugar is added at some point along the way. Added too late, and — depending on the chocolate maker’s refining equipment — large sugar particles may result in a gritty texture (interestingly, Taza Chocolate leaves large sugar particles in its chocolate on purpose, and the texture of their chocolate is quite unique).

Side note: one thing I’m still trying to figure out is what happens if sugar is added too EARLY in the grinding/refining process? Why don’t chocolate makers just add sugar at the very beginning, as soon as the nibs have liquefied in the melangeur? Is it possible for sugar particles to become TOO small?

Sugar’s effect on the intensity of chocolate’s flavor:

Generally, in dark chocolate anyway, the lower the percentage of sugar, the higher the percentage of cocoa mass. At least theoretically. The thing is that most chocolate makers also add additional cocoa butter to their chocolate, and the “cocoa solids” percentage stated on chocolate bar wrappers includes the combined weight of the cocoa mass AND the added cocoa butter. So a 70% dark chocolate could be 30% sugar and 70% cocoa mass (known in the industry as “two-ingredient chocolate”). Or it could be 30% sugar, 20% cocoa butter, and only 50% cocoa mass. Suddenly that chocolate isn’t sounding so dark, is it?

Earlier in this post you learned that sugar makes chocolate thicker by reducing its relative cocoa butter percentage, and chocolate makers often add extra cocoa butter in order to thin it out again (and sometimes to improve its texture). Given that cocoa butter has very little actual chocolate flavor, the more additional cocoa butter in a chocolate, the less intense its flavor.

Enrobed chocolate bonbon“Couverture” chocolate — the chocolate used by chocolatiers to make bonbon shells and enrobe truffles —  by definition must contain over 31% added cocoa butter. So that means that a 65% dark couverture chocolate is likely made from 35% sugar, at least 31% added cocoa butter and, at the very most, only 34% cocoa mass (most likely less because most cocoa makers also add soy lecithin). 34% cocoa mass does not an intense chocolate make.

So as you can see, sugar interacts with other ingredients in chocolate in complex ways by displacing cocoa butter and affecting texture. Chocolate makers have been trying to tweak processes and recipes for hundreds of years. Replacing sugar with a sweetener that has a completely different chemical composition is complicated, requiring multiple adjustments along the way, and a lot of trial and error.

It will take a lot of thought, time and experimentation before chocolate makers figure out how to make great chocolate sweetened only with stevia, but I’m guessing it can be done. I’m curious which chocolate maker will be the first to make that leap.