I spent too long looking for a potion brewing design that met a few criteria I had:
- Not more than 6 blocks tall
- Can brew any potion
- Can brew an entire shulker box of potions at once
I could’ve gone with nine of the one-wide tiling designs and hooked it up to a hopper line but that was still a bit too involved for what I wanted, since swapping out ingredients to brew different potions would be a hassle (and since I’m brewing a whole shulker at once, I’d have to swap out ingredients in, at minimum, 9 droppers, and in the worst case, 45 of them).
This isn’t the cleanest design and I could certainly compact the redstone a bit (if I knew what I was doing) but this works just fine as it is and it fits in my potion room, so no need to mess with it for now.
There are three main components: the bottle input, the ingredient input, and the purge circuit. Each brewing stand has a hopper below, behind, and above it. The hoppers below are locked by default by a row of redstone torches next to them. These get unlocked by both the bottle input and purge circuits.
The main trigger for the ingredient input is a stone button (1), which powers the circuit for the exact amount of time to unlock the hoppers to let three items through – three bottles from the brewing stands (clearing any previously brewed potions) and three items in the counter circuit (2). This powers the rail that the bottle minecart sits on, through the repeater at (3).
Each time the bottle minecart runs through the loop, it hits a detector rail (4). This powers a dropper-hopper circuit (5) which unlocks the counter circuit long enough to let one item through (6). So the minecart runs through three times, enough to distribute 27 bottles to the 9 brewing stands, and then stops. Since these hoppers point into the side of the brewing stands, this is also used to load in blaze powder.
The purge circuit simply unlocks all the hoppers underneath the brewing stands, letting all the bottles out.
The ingredient distribution is just another chest minecart running over the top of the brewing stands, with a button to send the minecart (and a bounce-back at the other end of the track).
Using this system is incredibly simple. First, you purge everything so you’re starting with empty brewing stands. Then you load up bottles into the bottle input.
Then hit this button at the front of the machine.
This sends the bottle minecart through and fills up the brewing stands. While that’s running, you can toss ingredients into the ingredient cart and send that off (the bottles will get filled up before one brewing operation can complete). Then you just send more ingredients through for each step of the desired potion, until you’re done. At this point if you don’t need to brew any more potions, you can just purge everything, or if you want to brew more, you can send more bottles through and the previous batch will get partially cleared (some of the hoppers stay locked a bit too long so only about 22-24 of the 27 potions comes through to the output – this is why the purge circuit exists).
The output chest can also be replaced with a shulker box to fill them directly.
I’ve also put consideration into the greater design of the room, providing barrels to store ingredients and more to store potions.
In the back of the room there’s also a patch of nether wart.
The trickiest part of this was getting the timing for unlocking hoppers correct; a stone button provides exactly the duration needed to move three items, but I needed the dropper-hopper combo to unlock the counter circuit for exactly the duration needed to move one item back. Altogether I’m very satisfied with the result and now have way too many potions.