Minecraft: Java Edition 21w05a snapshot adds lush caves from 'Caves and Cliffs Update'

Minecraft Caves and Cliffs Update Image (Image credit: Mojang Studios)

What you need to know

Minecraft: Java Edition tests future updates through snapshots, or temporary "slices" of larger updates.
The latest snapshot, 21w05a, is releasing today with a number of new changes, bug fixes, and more.
The largest change is the addition of blocks and plant life from lush caves, as part of the future 'Caves and Cliffs Update.'
There are also changes to additions made in previous snapshots, including to the sculk sensor.

The latest Minecraft: Java Edition snapshot is here, and snapshot 21w05a will certainly make a lot of Minecrafters very happy. While natural cave generation and new in-world features still aren't here, snapshot players will be able to try out a number of new blocks and plant life that will become a part of lush caves in Minecraft's Caves and Cliffs Update. There's a lot for players to look at in Creative mode, on top of a number of tweaks and changes that affect features added in earlier snapshots.

The Caves and Cliffs Update for Minecraft is planned to release sometime in Summer 2021, and will be one of the largest Minecraft updates to date. Expect new mobs, blocks, items, terrain generation, and even ore to all make their way into the Caves and Cliffs Update.

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The full changelog for Minecraft: Java Edition snapshot 21w05a includes:

New features

Azalea bushes as well as flowering azaela bushes!
Added cave vines and glow berries!
Added dripleaves!
Added decorative blocks for the upcoming lush caves: hanging roots and rooted dirt!
Added moss!
Added spore blossom!

Caves vines and glow berries

Cave vines grow down from the ceiling, like weeping vines
When they grow they have a chance of producing glow berries
Glow berries are a natural light source as well as a food source
Foxes eat glow berries
Use glow berries to plant new cave vines
Bonemealing a cave vine will create glow berries

Dripleaf

Small dripleaf needs moisture, so it grows on clay or underwater
Small dripleaf grow into big dripleaf when bonemealed
Big dripleaf grows taller when bonemealed
If you stand on a big dripleaf, it will tilt after a while and you will fall off
You can crouch or jump to prevent a big dripleaf from tilting
A tilted big drip leaf will tilt up again after a while
The big dripleaf will break when hit by a projectile
The wandering trader will sometimes sell small dripleaf plants

Moss

Two new decorative blocks: moss block and moss carpet
Moss carpet can be crafted from moss blocks

Spore blossom

A beautiful large flower placed on ceilings
Particles drip from it

Changes

The stonecutter can be used to craft the different copper block variants
The stages of copper oxidization are now called "Copper Block," "Exposed Copper Block," "Weathered Copper Block," and "Oxidized Copper Block," in sequence of least to most oxidized
Drowned now have a chance of dropping a copper ingot, they no longer drop gold ingots
Added new sculk sensor events
Changes to powder snow

Sculk sensor

Added the following game events that the Sculk Sensor reacts to, along with corresponding frequency value:
- Minecart Moving, Ring Bell, Block Change: 6
- Drinking Finish, Prime Fuse: 7
- Mob Interact: 8
- Equip, Shear, Ravager Roar: 9
- Entity Place: 12
- Entity Killed: 13
- Shulker Close: 14
- Shulker Open: 15
Block Change is for when player or dispenser action has changed a block. Example: cake slice being eaten
Mob Interact is for specific mob interaction events that cause vibrations
Prime Fuse is for both TNT and Creepers

Powder snow

Flaming arrows now get extinguished when they collide with powder snow
Skeletons now convert to strays when frozen
Powder snow is now pushable by pistons and sticky pistons
Foxes can now walk on top of powder snow without falling in

Technical changes

Improved performance when using many overrides on an item model
Copper oxidization is now a random tick effect and thus affected by the randomTickSpeed game rule

Bug fixes

Mobs suffocate / go through blocks when growing up near a solid block
Debug world spawns player at y=2 instead at y=70 where all the blocks are
Baby turtles take damage when pushed against ceiling
Sound spam while in water and lava at the same time
Pufferfish triggers tripwire without colliding with it upon reloading the game
Starting server outputs "unable to resolve BlockEntity for ItemStack" errors
Baby zombies / piglins take damage when pushed against ceiling by bubble columns
Baby husks, piglins, zombies, zombie villagers, and zombified piglins take damage when jumping into a space with a solid block above it
Standing in fire and water spams the extinguish sound
Player is dismounted when standing on farmland while riding a horse/boat while the farmland turns to dirt, causing a desync
Pufferfish phases through blocks after reloading world
chatDelay in "options.txt" has a space between the colon and the value
Pufferfish hitbox incorrect when reloading world
Large amounts of copper blocks lag the server and causes the worldsave to take forever
Cauldrons don't fill with powder snow in some biomes
"Fire extinguishes" Sound repeatedly plays when a mob that burns in daylight is in powder snow
Occasional desync when trying to enter / exit a boat while the server is lagging
Baby cows can suffocate on stairs
Powder Snow causes Z-Fighting with Falling Blocks
Sculk sensors do not react to minecarts being driven
Bell ringing event is not considered a vibration
Drinking potions or milk doesn't cause vibrations even though eating does
Inconsistency: Filling cauldrons with liquids or powder snow is not detected by sculk sensors
Sculk sensor can't detect setting a fire with fire charge
Extinguishing a campfire is not detected by sculk sensor
Blocks being placed or picked up by an enderman are not detected by sculk sensors
Sculk sensors don't properly detect eating from other mobs
Sculk sensors do not detect buckets of fish being emptied
Sculk sensors don't detect shulkers opening and closing
Flame arrows repeatedly trigger sculk sensors
Sculk sensors can sense players sneaking in water when they move, even when they're not swimming
Sculk sensors don't detect certain flying mobs
The fire extinguish sound plays every tick when the player is on fire and freezing
Villages will always generate at least on y=0
Directly breaking fire does not alert sculk sensors, but removing its supporting block correctly does
Breaking paintings / item frames / glow item frames does not alert sculk sensors, even though placing them does
Sculk sensor doesn't detect squids swimming
Sculk sensors do not detect when ghasts shoot
Sculk sensors don't react to ravager roars
Ocelots and cats can still emit vibrations while sneaking
Shooting bow with flame enchantment while sneaking triggers sculk sensor
Sculk sensor detects wrong sound for fishing rod
Sculk sensors do not detect the placement of boats and minecarts
Sculk sensors do not detect candles being placed into cakes
Sculk sensors do not detect when creepers are set off with flint and steel
Sculk sensors do not detect lighting TNT with flint and steel
Sculk sensors do not detect placing things in flower pots
Sculk sensors do not detect books being placed onto lecterns
Sculk sensors do not detect collecting water with bottles
Sculk sensors do not detect collecting honey bottles
Sculk sensors do not detect the breaking of bee nests and beehives in Creative mode
Sculk sensors do not detect when ender dragons shoot fireballs
Sculk sensors do not detect removing things from flower pots
Sculk sensors do not detect when candle cakes are eaten
Going into a dimension that has height higher than the maximum height crashes the game
Game crashes upon instantly click-replacing the block underneath a bamboo sapling with another bamboo
Baby llamas suffocate when below a solid block while standing on top of a carpet
Placing glow lichen in lava creates waterlogged glow lichen
Shulkers get rotated when upgrading to 21w03a
Shulker is sometimes mis-rotated when player teleports through a nether portal and reloading an active chunk with Shulker
Crammed enitities pushed through blocks when growing to adults
Commands setblock and fill don't work at or above height 1024 in some cases
Client can dismount vehicles independently from the server, causing a de-sync
Boats dismount you in the direction the boat is facing instead of the direction of the player
Importing custom world file height is limited to 2047 instead of 2048
Game crashes when generating a world with increased height limit
Shulkers are spawned slightly mis-rotated after a shulker was hit by another shulker's shulker bullet
Standing near a shulker slightly lifts you when they open
Shulkers are often incorrectly rotated upon generation
Copper blocks are named differently from bedrock edition