In Minecraft, a Potion of Weakness is a simple brew that reduces melee damage and is often used as a splash potion to weaken mobs or to cure zombie villagers when combined with a golden apple.

What you need

Gather these ingredients and items:

  • 1 Brewing stand
  • Blaze powder (fuel for the stand)
  • 1–3 Water bottles (glass bottles filled with water)
  • 1 Fermented spider eye

To make the components:

  • Glass bottles: Smelt sand into glass, then craft 3 glass in a “V” shape.
  • Fermented spider eye: Craft from 1 spider eye + 1 sugar + 1 brown mushroom.
  • Blaze powder: Craft from blaze rods dropped by blazes in Nether fortresses.

Step‑by‑step: brewing the Potion of Weakness

Follow these steps once you have everything:

  1. Place the brewing stand.
  2. Open its interface and put blaze powder into the fuel slot on the left.
  3. Put 1–3 water bottles in the three bottom slots.
  4. Place the fermented spider eye in the top ingredient slot.
  5. Wait for the brewing progress bar to complete; each bottle becomes a Potion of Weakness.

Each potion brewed this way reduces melee damage by 2 hearts while it’s active.

Optional: make it a splash potion

Splash potions are throwable and are what you use for things like curing zombie villagers.

To convert it:

  1. Brew the basic Potion of Weakness as above.
  2. Leave the potions in the bottom slots of the brewing stand.
  3. Put gunpowder in the top ingredient slot.
  4. Let it brew; the potions become Splash Potions of Weakness.

You can also extend the duration of a normal Potion of Weakness by adding redstone dust as the top ingredient, which is useful if you want the effect to last longer.

TL;DR: Put blaze powder in your brewing stand, water bottles in the bottom slots, and a fermented spider eye on top to brew Potions of Weakness; add gunpowder afterward to make them splash potions.

Information gathered from public forums or data available on the internet and portrayed here.