Organic Compost

Organic Compost next to the Rich Soil it becomes

Organic Compost slowly rots into Rich Soil, the best soil in the mod. You don’t feed it or use it: place it, leave it, come back later. Sunlight, water and certain blocks around it make it go faster.

An Organic Compost heap beside a pond, with mushrooms and Rich Soil around it to speed it up.

Setting up a heap

Every so often (on average every 68.3 seconds) each compost block gets a chance to rot one step further. After 8 steps it turns into Rich Soil. Its chance each time adds up from what’s around it, in the 3×3×3 space centred on the block:

• Activators: +2% each. Other compost, Rich Soil, mushrooms and mycelium all count, and the block counts itself: Brown Mushroom ColonyOrganic CompostRed Mushroom ColonyRich SoilRich Soil FarmlandBrown MushroomMyceliumPodzolRed MushroomShelf Mushroom
• Sunlight: +10%, or only +5% in the shade. Open sky above the heap or right next to it is enough.
• Water: +10% if there’s any water in that space, even one waterlogged block.

the compost block, which counts as an activator itself sunlight is checked just above each cellAll 27 blocks count. Each activator adds 2%, any water adds 10% once, and sunlight adds 10% (only 5% in the shade).

So the best heap is a big pile of compost outdoors, with water running beside it. The block in the middle of a solid 3-wide pile counts 27 activators: 54% before sunlight and water.

Torches don't help

Only sunlight counts, and night counts as sunlight too. A torch-lit cellar always gets the shade bonus, while a heap under a glass roof still sees the sky.

How long it takes

Setup	Chance each time	Rich Soil in about
One block in the shade, no water	7%	2.2 h
One block under open sky	12%	76 min
Open sky, next to water	22%	41 min
Middle of a 3×3 layer of compost, open sky, water beside it	38%	24 min
Middle of a solid 3×3×3 pile, open sky, water	74%	12 min

These are averages: a single block can finish much sooner or later. Try your own heap here:

Open sky above it or a neighbour (night counts too; torches don't)Water touching it, even diagonally (source, flowing or a waterlogged block)Activators around it (compost, Rich Soil, mushrooms…) in the 3×3×3 cube: 0Game rule randomTickSpeed: 3 (default 3)

chance each time it gets a turn12%

• 1 activator +2%
• sunlight +10%
• water +0%

steps to Rich Soil

8

turns needed (average)

66.7

time between turns (average)

68 s

time to Rich Soil (average)

75.9 min

Times are averages. A single compost block can finish much sooner or much later than this; a big pile evens it out.

Stages

From fresh compost to Rich Soil

1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7
8. 8

The block changes look as it rots. A comparator next to it reads 8 from fresh compost and one less per step, so you can check a buried heap.

Recipes

Crafting (shapeless)

Crafting (shapeless)

Good to know

• Breaking compost gives back Organic Compost, but its progress is lost: it starts again from step 1.
• Mushrooms survive on compost in any light, but mushroom colonies only grow on Rich Soil.
• Some villages come with a compost heap you can raid (Villagers).
• A canvas rug on top lets sunlight through, so you can cover a heap and keep the bonus.