Java Edition 21w06a

Not to be confused with 20w06a.

 Note: the 2 "flavors" are what the 2 new cave types, spaghetti and cheese caves, are called on Minecraft.net.

21w06a is the ninth snapshot for Java Edition 1.17, released on February 10, 2021, which adds new cave generation and a new build height limit.

Worlds created prior to this snapshot cannot be loaded and edited in this version without the NBT editors, due to there being no upgrade path towards the new height.

World generation

 * Caves
 * Added aquifers and new noise caves, which come in two "flavors": "spaghetti" and "cheese" caves.
 * The old cave generation still generates, combining with the new caves.


 * Spaghetti caves
 * Long noodle-like caves, sometimes wide like tagliatelle.
 * Utilise noise generators for generation.
 * Can form cave entrances when they intersect with land.


 * Cheese caves
 * Utilise noise generators for generation.
 * Like the holes in swiss cheese, often form caverns of various sizes.
 * Can form cave entrances when they intersect with land.


 * Aquifers
 * Used to generate bodies of water in new caves. As of now, it's only used below Y=31, meaning any noise caves between the two heights are flooded with water. This will be fixed later.
 * Magma blocks may generate at the bottom of these new water bodies, creating downward bubble columns.
 * Replaces the old underwater cave carvers/canyons.


 * Mineshaft
 * Mineshaft pieces no longer generate if they were fully floating in the air.
 * Corridors now generate with log pillars for support if needed.
 * Removed the floating cobwebs.

Blocks
Big Dripleaf


 * Will no longer stop tilting while sneaking on, jumping on, or even jumping off it.
 * Will now tilt quicker.
 * Now just tilt when hit with a snowball.
 * Can now be used with redstone.
 * Powering a dripleaf will now prevent it from tilting down.
 * Powering an already tilted dripleaf will tilt it back up.
 * Powering a dripleaf down will allow it to tilt down again.
 * Powering a dripleaf does not prevent tilting because of projectiles.


 * Hanging Roots


 * The texture has been changed.


 * Small Dripleaf


 * The texture has been changed.

General

 * World
 * Raised the height limit to 384 blocks.
 * The height limit now goes from -64 up to 320 blocks.
 * Due to this change, the old worlds can't be loaded in this version.

Trivia

 * This is the first snapshot for the Caves & Cliffs Update that didn't add any new item.
 * This snapshot marks the first time since 12w07a that the height limit was increased.

Video
Video made by slicedlime on the gameplay changes: