Feed The Beast Wiki
This page is about the Forestry Fermenter. For other uses, see Fermenter.


The Fermenter is a machine added by the Forestry mod. It's primary uses are the conversion of organic materials into Biomass, and the creation of Short Mead from Honeydew and Liquid Honey



Firstly, the Fermenter needs power, in the form of Minecraft Joules (MJ) This enables the Fermenter to operate. It will accept up to 17MJ/t, with lower inputs slowing the rate at which it runs. The machine runs fine off of a single Stirling Engine, if a little slowly.

The Fermenter has two primary uses- the creation of Biomass, and the creation of Short Mead

Liquids produced by the machine can be directly canned within the machine, or exported via Waterproof Pipes or Liquiducts

Biomass Creation

In order to produce Biomass, the Fermenter needs several things.

Firstly, the machine will require a constant supply of either Water, Liquid Honey or Fruit Juice. Whilst water is easier to set up, Liquid Honey or Fruit Juice will increase the machine's efficiency by 50%

Secondly, the machine will require a source of organic material. Different materials produce different amounts of Biomass per item (as shown in the table labelled organic materials, below), so it is best to choose your organic material wisely.

Item Output per Item with Water (mB) Output per item with Fruit Juice or Honey (mB)
Saplings Between 250 and 1500 (see Saplings table) Between 375 and 2250 (see Saplings table)
Wheat 100 150
Cactus 200 300
Sugar cane 200 300
Mushroom 200 300
Plantball 400 600
Compressed Plantball 500 750

Versions of the modpack running on Minecraft 1.5 have different yields of biomass for different saplings. This is due to the saplings "Sapiness" genetic trait, discovered through Tree Breeding.

Sapling Sappiness Output per Item with Water (mB) Output per item with Fruit Juice or Honey (mB)
Non-Forestry Saplings Lowest 250 375
Balsa, Larch, Pine, Lime, Chestnut, Walnut, etc. Lower 500 750
Cherry Kapok Ebony, Mahogany, Willow, etc. Low 750 1125
Lemon, Plum Average 1000 1500
Mahoe High 1500 2250

It will also require a form of Fermentation Item. There are three to choose from: Fertilizer, Mulch and Compost. Mulch or Compost have a 20% longer lifespan than Fertilizer.

The machine will also require a constant supply of MJ.

Short Mead Creation

In order to produce Short Mead, the Fermenter needs to be set up in the following manner.

A constant supply of Liquid Honey needs to be supplied to the machine. This can be pumped into the machine through pipes, or placed in the left-hand liquid slot through Cans. Approximately 1 bucket of Liquid Honey is used to create 1 bucket of Short mead.

Honeydew needs to be supplied in the top middle item slot. One Honeydew produces 500mB of Short Mead.

A Fermentation item is also required, and have identical rates of use as with Biomass production.

Interaction with Pipes

One thing that is often confusing for people using a Fermenter is the correct side in which to pipe items.

Input liquids (i.e. Water, Liquid Honey and Fruit Juice) should be pumped, either in item form (e.g. cans and buckets) or liquid form, into the left side of the block. The liquid shows in the left side of the interface, with the far left item slot intended for liquid item input.

Organic material, or Honeydew, should be piped into the top of the machine. These show in the top-middle item slot in the interface.

Fermentation Items (Fertilizer, Compost or Mulch) should be piped into the bottom of the machine. these show in the bottom middle item slot in the interface.

Liquid output should be piped from the right side of the machine.

If you want the machine to automatically can the liquid output, first place empty liquid containers (e.g. buckets or cans) in the top right item slot. When the Fermenter has enough liquid output, it will automatically place it in the can, and move it to the bottom right slot. These can then be manually removed, or pumped out the right hand side of the machine using Transport Pipes and some form of Engine or Autarchic Gate.

Energy can be inputted from any free side. This normally means power is placed on either the front or the back of the machine.