There’s a new form of chocolate out there that wants to replace chocolate as we know it. The reason it’s not going to is the same reason all substitute foods keep failing to deliver on their promises: Accurately replicating food is almost impossible.
In a study published today in PNAS, physics researchers at Temple University describe a new chocolate-making technique that let them cut the fat content — which usually made-up half or more of the bar — by 20 per cent. Previous attempts at cutting the fat by that much had resulted in a chocolate so chunky and slow-flowing that it clogged the machines. The new chocolate, however, flowed as easily as the original.
Researchers accomplished the trick by electrorheology, a technique in which an electric field is set in the same direction as a moving liquid. The field flips the particles — in this case, cocoa solids — into chains that move together, making the liquid flow easier.
Lead researcher Rongjia Tao of Temple University noted that, although the method had never been used on food before, it wasn't an entirely new technique.
"Dark chocolate, basically, is a mix of cocoa solids and the liquid is cocoa butter. It's a liquid suspension," Tao told Gizmodo. "[The same technique] is also used to reduce the viscosity of crude oil in the pipeline, the crude oil is also a liquid suspension."
Tao's hunch paid off when his low-fat chocolate moved easily through the machinery without a hitch. But chocolate, even at its worst, is not crude oil. It's not enough for it to flow through machinery without clogging it, it also needs to taste and feel just right. In a statement, Tao had described the flavour as "wonderful", adding that many in his lab called it "better than the original".
That's where the problems start. "Better" is not only a subjective judgement of taste but also another way of saying that something just tastes different than the original. And that difference -- whether you happen to find it more or less palatable -- is the basic problem that all food substitutes keep running into. When a new fake-meat burger or lab-grown chicken breast or a low-fat lolly comes out, they don't promise a taste that's better than the original. They promise an identical one -- and over and over, they fail to deliver it.
Elaborating on the question of the difference in taste of his chocolate to Gizmodo, Tao said, "I myself couldn't find the difference in flavour. But some people find the flavour more concentrated. It's stronger."
Flavour, though, as important as it is, is just one part of the experience. In fact, for chocolate, it might even be considered secondary to its texture in your mouth. Last year, for the first time, researchers were able to isolate the flavour of fat independent of its feel. The results were not particularly pleasing, with many respondents referring to the taste as gross and, even more disappointingly, surprisingly "unfatty".
The unhappy reactions to the taste, and the difficulty synthesising it all, point to a basic fact about fat. Fat doesn't taste good because of its flavour, it tastes good because of its feel. It makes our foods creamier, silkier, meltier. And that experience -- even if you can manage to make the chocolate quite smooth, like Tao says his method can -- is almost impossible to replicate.
Replicating foods while subtracting a primary ingredient -- say, the fat from a chocolate bar or the meat from a burger -- is an almost impossible task. It demands that every sensory experience, not just the taste, by reproduced practically flawlessly.
Even when pulled off quite well, the results of foods copies often seem to fall more into a food uncanny valley than true duplicates. Perhaps scientists should just forget about making copies and instead move their research towards truly novel foods that stand on their own. We have enough replicant foods that are almost (but never quite) right.