The efficiency of a Minecraft witch farm depends on the location of the hut, and lower heights lead to higher efficiency.
Witches can drop more loot and potions if they fall to their death or are attacked by the player, and potions can be obtained when attacking them.
Lecterns can be used to adjust the drop rate of each potion type, with healing potions having the highest drop rate and water breathing potions having the lowest.
The witch hut where witches spawn is small and there's usually only one nearby, making the farm's limitations clear. So, to improve this a bit, we'll utilize the huts that are partially buried underground. If we consider the efficiency of the lowest hut (Y: 36~42) as 1, the efficiency decreases to about 0.8, 0.79, and 0.62 as the height increases. While these aren't exact numbers, it's clear that higher huts lead to losses.
In this farm, witches will fall to their deaths even if left alone, but if you swing your sword at them before they fall, you can get more loot and potions. Witch potions only drop if the player directly kills them. So, for the farm to perform at its best, player participation is essential.
Simply swing your sword when the minecart pops out of the dispenser. Wait and swing as soon as you see the minecart. The best timing is 5 game ticks (250ms) after the minecart appears. If you see experience orbs drop when the witch dies, it means your attack hit. If you don't see them, adjust the timing in increments.
Witches drop 4 types of potions: (Healing / Fire Resistance / Water Breathing / Swiftness). This farm allows you to obtain all 4 types of potions by flipping the pages of a lectern. Flipping the page switches to a mode specialized for each potion drop, allowing you to focus solely on swinging your sword when the minecart appears.
Healing potions are the most common, and they always drop regardless of the mode. There's a chance factor involved in witches drinking potions. For example, even if a witch touches lava, it's not guaranteed they'll drink a Fire Resistance potion.
Fire Resistance potions are the second most common. Swiftness potions are next, and Water Breathing potions are the least common. Witches can spawn at a rate of about 1290 per hour at the most and 1220 at the least. As you can see, even with a high witch spawn rate, the Water Breathing potion (on the right) only yielded 90 potions.