Soylent is a crazy idea to replace food with a drink that contains all the nutrients the body needs. The team behind Soylent asked me to make some 3D printable measuring cups of non standard volumes for them. You can download the CAD here. I included the STL for printing and the SolidWorks file so you can re-export the STL if you need to.
The sizes are 4/3 cups, 4/3 tablespoons, and 5/32 teaspoons, from largest to smallest. The reason the handles are long is so you can print it without using any support material. The big one isn’t hard to grip, it’s just different. I printed these in ABS on a Lulzbot 3D printer with about 50% infill. You can probably get away with less. These are NOT bacteria resistant as is. There are lots of little pits and grooves that bacteria could get in. Coating the inside with acetone to smooth it would help, but if you want to be really safe, use a food safe coating. ABS and PLA are not rated as food safe by anyone, but you also probably won’t die or get poisoned by it. People print cookie cutters and shot glasses and stuff all the time and really the bacteria would be a bigger potential problem. But you probably don’t want to be that guy who has to explain to the toxicologist that a stranger on the internet said it would be fine. The safest way to print these is in a safe material like HDPE or PET, or to correctly coat them. You can also use them as positive molds if you want to use a different process. How these will fare in heat depends on what you print them out of and if/how you treat them afterwards. The ones in the picture made from ABS (same plastic as Legos) are very sturdy and you’d probably have to stomp on them with boots to break them.
Manufacture and use these at your own risk and be safe.