Soylent should be more convenient than real food, but the world is set up for real food, so sometimes it is not. You’re not supposed to carry it warm for hours, but it’s not water-soluble enough to just mix by shaking, or even with a spoon. You get clumps and those protective cysts of dry powder on the sides of the glass. Enter Blender Bottle, a normal water bottle with a whisk ball inside it. As long as you don’t overfill it it mixes extremely well. Not quite immersion blender well, but it’s pretty homogeneous. And you can do it anywhere.
Technically you could accomplish this with any water bottle + the whisk ball. The advantage of the Blender Bottle is 1. not every water bottle can stand up to that amount of shaking and 2. the Pro Stak System. You can buy little ~tupperware containers that interlock with the water bottle. Unfortunately they don’t hold a useful amount of soylent, I use a ziploc bag for those. But they are big enough to carry around salt. I always drink water with salt. Nothing was stopping me from carrying a salt shaker with me before, but I didn’t, so I didn’t drink enough water out of the house. Apparently I will carry an attachment to my water bottle filled with salt. So the blender bottle has solved two problems for me.
Credit to Brian for recommending a version of the Blender Bottle to me.