A fermented spider eye is one of the most important brewing ingredients in Minecraft. On its own it does nothing, but in a brewing stand it “corrupts” potions, flipping them into their opposite effect. It is the key to Weakness, Harming, Slowness, and Invisibility potions, and it takes just three easy-to-find items to make.
This guide covers the recipe, where to get each ingredient, and exactly which potions a fermented spider eye is used for. Everything here is confirmed in the current 2026 version of Minecraft (26.2).
Quick answer: combine 1 spider eye, 1 sugar, and 1 brown mushroom on a crafting table (in any arrangement) to make 1 fermented spider eye. It is a brewing ingredient used to turn potions into their negative versions.
Fermented Spider Eye at a Glance
| Detail | Value |
|---|---|
| Recipe | 1 spider eye + 1 sugar + 1 brown mushroom |
| Type | Shapeless (any arrangement) |
| Main use | Corrupts potions into their opposite |
| Makes | Weakness, Harming, Slowness, Invisibility |
The Recipe
At a crafting table, place 1 spider eye, 1 sugar, and 1 brown mushroom anywhere in the grid. The recipe is shapeless, so the positions do not matter. You get 1 fermented spider eye.
One thing to watch: it has to be a brown mushroom, not a red one. A red mushroom will not work.
Getting the Ingredients
Each of the three parts is easy to gather:
- Spider eye: dropped by spiders and cave spiders when killed, at about a 1 in 3 chance (a Looting sword raises this). Witches also drop them, and you can find spider eyes in some loot chests.
- Sugar: craft it from sugar cane (1 cane makes 1 sugar), which grows on water edges. You can also craft a honey bottle into 3 sugar.
- Brown mushroom: grows in poorly lit areas, on the surface of swamps, in dark oak (old growth) forests, mushroom fields, and the Nether. Look in shady spots and caves.
What a Fermented Spider Eye Does
Its whole purpose is brewing, where it acts as the “corruptor” that flips a potion into its opposite. Brew a fermented spider eye into these potions:
- Potion of Weakness: brew it straight into a water bottle (no awkward potion needed). Weakness lowers melee damage and is famous for curing zombie villagers when combined with a golden apple.
- Potion of Harming: brew it into a Potion of Healing (or Poison) to turn healing into instant damage.
- Potion of Slowness: brew it into a Potion of Swiftness (or Leaping) to slow the target instead.
- Potion of Invisibility: brew it into a Potion of Night Vision to turn invisible.
In short, whenever a potion has a “negative” counterpart, a fermented spider eye is how you make it. Our best Minecraft potions guide covers the full brewing tree, and the invisibility potion guide walks through that specific brew.
Frequently Asked Questions
Combine 1 spider eye, 1 sugar, and 1 brown mushroom on a crafting table. The recipe is shapeless, so the arrangement does not matter, and it makes one fermented spider eye.
A spider eye (from spiders), sugar (from sugar cane or a honey bottle), and a brown mushroom. It must be a brown mushroom, not a red one.
In dark, poorly lit areas, on the surface of swamps, in dark oak forests, mushroom fields, and the Nether. They need low light to spawn and grow.
Brewing. It corrupts potions into their opposite effect, making Weakness, Harming, Slowness, and Invisibility potions.
Brew a fermented spider eye directly into a water bottle, no awkward potion required. Weakness potions are used to cure zombie villagers alongside a golden apple.
Brown. A red mushroom will not work in the fermented spider eye recipe.
A fermented spider eye is cheap to make and unlocks a whole side of brewing: the negative potions. Grab a spider eye, some sugar, and a brown mushroom, craft it, and you are ready to brew Weakness, Harming, Slowness, or Invisibility whenever you need them.
