Place 1 Brewing Stand
Add Blaze Powder as fuel
Put 1 Water Bottle in a brewing stand slot
Add 1 Fermented Spider Eye to brew a Potion of Weakness
To make a Splash Potion of Weakness, brew the Potion of Weakness with Gunpowder
To make a Lingering Potion of Weakness, brew the Splash Potion of Weakness with Dragon’s Breath