Obsidian farming refers to methods of obtaining large quantities of obsidian. Obsidian does not generate naturally with the terrain (except in the End and Ocean caves), instead being created by natural events or player action.
The simplest method is to pour water over lava source blocks, either in a naturally-occurring lava pool or transported in buckets. A more advanced (and renewable) method is to take advantage of nether portals being created when no destination portal is in range or the recreation of the 5×5 platform when using the end portal.
Most methods of obsidian farming require manual mining. Obsidian is one of the toughest blocks in the game, so you'll need the right tools to take care of it. Enchanting a pickaxe with Efficiency greatly speeds up the farming process. With a beacon, the Haste and Haste II effects can be used to reduce mining time further. Below are the mining times for each level of enchantment.
|Without Haste||Haste I||Haste II|
Using Efficiency V without haste, it takes about 2.25 seconds to mine each block, or approximately 26.7 blocks of obsidian per minute. With Haste, this is reduced to around 1.85 seconds per block, or 32 blocks per minute. Haste II further reduces the time to about 1.6 seconds per block, or 38 blocks a minute.
The simplest ways to obtain obsidian is to find lava and "drench" it with water to convert it into obsidian. This is not a renewable method of farming obsidian, however, as lava source blocks are not a renewable resource.
In the Overworld, lava primarily occurs deep underground. However, it can occasionally also be found in small lakes, at or near the surface. It is also possible to find small lava springs, but since these typically only contain a single source block, they are not particularly useful.
One of the easiest ways to obtain obsidian is to find a lava pool, pour water on it, and then mine with a diamond pickaxe. It is also sometimes possible to find lava pools which have been naturally converted to obsidian by waterfalls.
When mining in this way, the top layer of obsidian usually has lava underneath it. Not only is this hazardous, it can also destroy the mined blocks before they are collected. A solution is to place water next to the obsidian and stand in it. When you mine an obsidian block adjacent to the water, the water should flow and freeze the lava before it has a chance to burn anything. It is also possible to place the water above the obsidian, however this is more likely to get in the way and decrease mining speed. Be careful to periodically move the water, especially if you are standing in it. Otherwise, it is possible that the water will reach its limit of 7 blocks and push you or items into the lava.
If you have obtained a large number of lava buckets, it may be more efficient to "cast" the lava rather than drenching and mining it. In this process, the lava is placed as desired and then covered in water to convert it into obsidian. In this way, obsidian structures such as Nether portals can be created in place without the use of a diamond pickaxe.
In order to aid in the process of casting, it is helpful to create a mold or frame.
When using a mold, the obsidian is usually casted one layer at a time. This is done by placing blocks around where the lava should go to prevent it from flowing. It can then be drenched in water.
If the obsidian structure is large, it may be easier to build a frame for the obsidian. The frame should be constructed so the lava can be placed on it. Next, water can be run down the sides next to where the lava will be placed. When lava is placed on the frame, it should immediately freeze without needing extra blocks to keep it from flowing.
This has the advantage of not requiring frequent reconstruction of the scaffolding and movement of the water. Additionally, the water streams can aid in mobility as it is possible to float in the waterfall. Care should be taken to remain clear of the area where obsidian is being created, however, as the solid blocks created can suffocate the player.
A quick video on how to find obsidian and how to make it.
Portal and End farming
When traveling through a Nether portal, a new portal is created at the destination. Breaking this portal yields obsidian and does not affect the portal in the other dimension.
To farm obsidian using Nether portals, first travel to the Nether and build a second portal at least 16 blocks away. Traveling through the second portal will bring you to a newly spawned portal in the Overworld. This portal will be about 128 blocks away from your original Overworld portal. You can then mine the new Overworld portal and repeat the process. Each time after the first should yield 14 obsidian.
If you built the Nether portal too close to the generated one, it may bring you back to the original Overworld portal rather than creating a new one. The Overworld portal may then do the same thing and not generate a new portal. Conversely, if you built the second Nether portal more than 16 blocks from the first, the generated Nether portal may more than 128 blocks from the original. For this reason, it may be necessary to adjust the location of the second portal in order to find the optimum distance.
Using two players, it is possible to use only a single portal. One player travels to the Nether, and the second breaks down the Overworld portal. The first player then uses the Nether side of the portal to return, generating a new portal nearby.
This can be done in single player by traveling to the Nether, breaking down the portal, storing everything in a chest, and dying. After returning to the Overworld portal, the process can be repeated.
It is also possible to travel through a portal and use a redstone mechanism to deactivate it before traveling back. If the portal in the Nether is not exactly aligned with the Overworld one, a new Overworld portal will be generated in a different location. Note that game remembers portal locations, so it may be necessary to wait up to a minute before returning.
In all cases, be sure to maintain a 4×4 area of flat ground with at least 4 blocks of air above the entire area near the location of the destroyed portal, either by filling in the holes left by mining out the base of the portal each time or by leaving the four base blocks unmined. If this is not done, you may suddenly find the newly created portal is in a cavern underground because there is no longer any valid location for a portal to spawn on the surface.
If the portal search fails to find a suitable location, it will create one with an air pocket and 4 extra pieces of obsidian. By creating the Nether portal so that the Overworld equivalent is over the ocean, it may be possible to use this mechanic.
The End platform
When using an End portal to travel to the End, a 5×5 platform of obsidian is generated. If the platform is damaged or destroyed, it will be restored. However, getting back requires either having killed the ender dragon or killing yourself.
The End Towers
The obsidian pillars in the End may be mined for obsidian. They are renewable since they regenerate when the ender dragon is respawned. These towers extend quite high and reach down to y=0. This requires being able to handle the Ender Dragon, however.
|This feature is exclusive to Java Edition.|
The biggest problem with obsidian mining is the time it takes; even with the best pickaxe and effects, it takes 1.6 seconds to mine a single block. Various methods can be used to break obsidian blocks automatically. The wither is usually key in these methods as it is capable of breaking obsidian blocks with its attacks.
By caging the wither in the Overworld and putting the player in a teleport loop through portals, a Nether portal is repeatedly generated and destroyed.
|Automatic Nether portal design (view on YouTube)|
|Automatic End platform design (view on YouTube)|
One of the first designs used the wither to break portions of the 5×5 obsidian spawn platform in the End, and regenerating it with a sand generator that pushed sand through the end portal situated in the Overworld. This method was patched however when the wither was made to shoot blue skulls that were capable of breaking any block. As such, this method works only in Minecraft 12w36a and several earlier versions. The following video is an explanation of how this method works.
|Outdated automatic design (view on YouTube)|