I hate to spread waistline-negative news, but yes – you can now buy a 3D printer that prints chocolate. The cocoa press has been in development for a full decade. Now it’s finally here and I’m pretty sure it’s solely responsible for one of the pounds I gained over Christmas.
At least it’s not yet cheap or easy enough to tempt most people.
This holiday season, I received a pre-built printer for $3,995—you can build one yourself for $1,750 or less—and thirty bars of perfectly fitting chocolate that I could use to fulfill my delicious goals.
I plugged in the printer’s screen, did the setup, popped a dark chocolate “cocoa core” into a cartridge, added a washable plunger cap, preheated the chocolate for 30 minutes, clicked “Start”… and immediately observed the nozzle tried to eat up her silicone baking mat.
I’m not sure if it was the Z height or the print head came loose a bit during shipping, but after adjusting both things I tried again and got this incredible 3D printed rose:
Just look at this flower. Look at the ridges. The whole surface that melts on your tongue? I can confirm that it was delicious, velvety and delightful. It took almost an entire bar of chocolate to make that one impression, but two minutes later it was gone.
The best thing about 3D printing chocolate is the incredible textures you can create. 3D printed gyroid filling? I just can not get enough. (You can see some examples of this stuffing in my video at the top of this story.)
And yes, the dark chocolate really tastes like chocolate, although because of its fat, palm oil was used instead of cocoa butter, presumably to improve the flowability. My wife is partial to dark chocolate, and while it’s definitely not the best we’ve ever had, she was happy with the quality.
But I can’t say the same about the milk chocolate and white chocolate – they’re a bit waxy and remind me of candy melts – and I never had another success like the first rose. Because the worst thing about 3D printing chocolate is controlling the heat.
This screw drive pushes a piston into slightly melted chocolate to squirt it out. It always sounded like I was having trouble.
Chocolate is fundamentally difficult to print, and not just using traditional 3D printing processes. With Cocoa Press, you can program the heat of the nozzle to the nearest tenth of a degree, because fractions of a degree can mean the difference between the product being hot enough to be liquid or too cold to even squirt out of the nozzle.
In my case, it sometimes took hours for the printer’s 65 gram chocolate syringe to reach a consistent temperature. Ellie Weinstein, founder of Cocoa Press, says this is due to a defect in one of my heaters—and will replace the entire cartridge and heater assembly to “anyone who asks”—but the heating can also depend on the chocolate itself. Dark almost worked with Cocoa Press’s default setting; Milk wasn’t much harder, but the white milk took most of the day, going up and down every half hour to find a temperature that would flow.
But even as I let the chocolate flow well, I quickly discovered that you can’t print anything too small or too pointy without drastically slowing the print speed. The chocolate needs time to cool and solidify before the nozzle attempts to print another warm layer on top.
It’s easy to see at what point this Sierpinski pyramid began to percolate:
The chocolate Sierpinski pyramid breaks down nicely into four smaller pyramids for serving – and a central octahedron for your family to fight over.
And there’s probably no point in printing a single calibration cube at all.
A very lumpy, too smooth calibration cube. The shiny layers could not cool down sufficiently.
Ideally, I would have slowed these prints down at certain altitudes to give them time to cool – but right now that’s a manual task that Cocoa Press can’t automate for you.
Although individual small objects are not particularly recommended, I couldn’t print particularly large ones either, as the 65 grams in a single bar of chocolate isn’t a lot. Weighing in at 59.5 grams, this pyramid approaches the limit of a single cartridge.
2.10 ounces of chocolate pyramids.
But you can print sheets with small objects, like these Mario stars I made:
I don’t like the surface textures of these stars, but they sure tasted good.
Or you can use vase mode, where a 3D printer prints in a single continuous spiral to build something large but hollow. The rose is a vase print, as is the bottom part of this coffee cup mockup – which I printed with white chocolate for the “cup” and milk chocolate for the top “lid”!
One of the cups from my video, made from two different types of chocolate.
Or you could theoretically trade in for a longer squeeze for a new cocoa kernel after the first one runs out… but again, it’s not automated. You’d have to program it to stop at the right point, or manually monitor it and stop it early when it’s running low. Even then, you would have to wait for the second cocoa kernel to preheat before continuing to print.
I tried the swap three times. One time I missed the timing and the printer ran out of air and just kept printing air. At one point the printing appeared to be working smoothly, but the printing later mysteriously failed. And once I tried switching from dark chocolate to white chocolate, but the chocolate got stuck in the nozzle and wouldn’t come out.
In practice, I found it much easier to simply print objects that would use up most of a stick all at once, then use the rest to print a second part of the object and just stick it straight into my mouth.
I missed the opportunity to continue this pressure. Nice simple touchscreen buttons.
Despite my difficulties, parts of the cocoa press seem pretty well thought out. I was impressed to see that the printer is natively supported by the popular PrusaSlicer, that all surfaces that come into contact with chocolate are easily removable and washable, and that my device even came with perfectly fitting cleaning tools. The touchscreen interface is easy to use, and if you know what you’re doing, all sorts of 3D printer optimizations are available to you. Andrew Sink of Tom’s Hardware, who knows what he’s doing, had a better time than I did.
“You know what you’re doing” probably describes the target group of this printer anyway. I can’t imagine a 3D printing newbie having the patience to enjoy the cocoa press even after spending more than $3,995 for a pre-made version and $49 for a pack of 10 pre-made chocolate centers.
But I could definitely imagine some DIYers spending the $1,499 on hardware, printing the plastic parts on their own existing 3D printer, spending 10 to 15 hours building it, and also learning to make their own chocolate centers – easy because they could.
Photos by Sean Hollister / The Verge