I want to puree frozen blueberries, blackberries, and muscadines to an ultra-smooth puree. Ideally, maybe 2 liters at a time. I don't mind if they get cooked a little in the process, as happens in some blenders. But I do NOT want to push air into the puree. All blender-like things I've used in the past incorporate air into whatever is being blended at high speed and at low speed they don't puree at all finely. By ultra-smooth I mean I want the product to be totally homogeneous with no perceptible grittiness, seeds, flecks of skin, or any kind of structure perceptible to tongue or eye.
A Champion juicer, set up in grinder mode, grinds without incorporating much air but the texture is pretty coarse. Blenders like the Vitamix might achieve the smooth texture but incorporate air.
I've thought about sealing the blender container and drawing a vacuum on it, but they aren't really designed with that in mind and I suspect air would leak through the gland where the shaft driving the blades enters the container and maybe even bring in bearing lubricant with it. I could build a vacuum cabinet and put the whole blender in it, but that would be a hell of a lot of work, and I'm afraid the blender would overheat without air to cool it. I suppose I could make a smaller vacuum chamber and put the finished puree in it after making it in some kind of blender and let it outgas a while but I suspect that would take hours and it would be drying out also. OK, instead of vacuum I could use just water vapor at half an atmosphere maybe. But that is beginning to seem like a real complicated project. Or I could custom build a blender from scratch so that there could be vacuum on both sides of the gland but air around the motor. That last actually appeals to me, but realistically I'll probably find the time to get around to it sometime in the next century. Maybe I could seal the blender and flush it with steam before blending. That actually sounds halfway sane.
I have an old Vitamix from back when the container was steel and the blades did the quick reverse trick. It worked it to death a few years ago and I haven't investigated getting it repaired but maybe it's repairable - I don't know.
Anyway, I'd appreciate any thoughts on techniques and/or equipment that might best do part or all of what I want. If the part about not incorporating air seems insurmountable, skip that and tell me what you've done to get truly ultra-smooth fruit purees where even the blackberry and blueberry seeds are obliterated. If there is a good way to do that, I suspect the flushing with steam trick might solve the air problem.