What is the most efficient way to make Concrete from Concrete Powder?

Question

I have an entire chest full of Concrete Powder that I want to turn into normal Concrete.

What is the most efficient way to turn the Powder into Concrete?

Answer 1

Another way to achieve this without the need for mining the concrete, would be to make use of the fact, that TNT now drops all the blown up blocks.

So you could insert the powder into a piston feed tape, which is next to water => powder gets converted to concrete.

The stream of concrete get blown up by TNT after that. With a simple water stream collection system in the end you can build something that works like a charm.

If you search for TNT blast chamber you will most likely find something that works wonders.

Disclaimer: Many of the designs out there make use of a bug [Java version 1.15] in the game to duplicate the TNT block that is used to blow everything up. I don't think that this will work for bedrock, but if you have enough gun powder you should be able to achieve the same result with normal TNT

Answer 2

As pointed out in a comment, this answer does not work for MCBE. It was written while the question had both tags.

The easiest way is to put a pickaxe into your main hand, concrete powder into your offhand and hold both mouse buttons ("use" and "break" actions) while aiming next to water.

The issue with this is that the items fly out in all directions, because you place a new block where they appear, accelerating them outwards. The best solution to this is to put hoppers everywhere around you, wherever items can land.

You will also eventually run out of concrete powder. To keep going, you need to dispense new concrete powder to your player (if you want to do it AFK). Either you find the perfect rythm for that (unlikely, especially with client lag) or you need to pick up excess powder with a hopper and direct it back into the dispenser. To make sure that the powder and concrete blocks don't end up in the same hopper, you can separate player and placement spot with a wall that has just a small hole in it to click through, but not big enough that items can fly through. Usually slabs should work fine, but if you want to be absolutely 100% sure, you need to use snow layers.