Tutorials/Slime farming

Slimes only appear in 10% of chunks from y=39 and below, as determined by your world seed. Various utilities exist to help locate these chunks, for example Amidst 3.6 or later, or http://chunkbase.com/apps/slime-finder. They can also spawn in higher y values in swamps, but building farms in swamps is impractical.

Once a slime chunk has been located, the best farm, and quite simple, is to dig out the chunk, all the way down to bedrock if so desired, and from y=38 start building platforms that cover the entire chunk every 3 blocks down. E.g., y=38, y=35 and so on. Around the chunk platform, make a 3 wide dead fall, and on the lowest level use water streams to either drown the slimes to death or push them against cacti (this method will destroy much of the slimeballs against the cacti).

Jioge's 1.8 Slime Grinder Tutorial
Many slime farms, especially those involving iron golems and the mechanic of slimes sinking into a water pit, were broken in 1.8 release of Minecraft. Jioge has the solution with this simple trap. Slimes are now able to swim upward and on a horizontal axis, so it is important to take note of how Jioge places the water in the drowning trap.

Ферма слизней