Breaking an instantly breakable block deals one "hit" of damage to the block behind it (i.e. the one the cursor is aimed at), unless that block is also instantly breakable. These hits are "remembered," and they can stack up to break the block behind. The quality of the hit is appropriate for the tool used. (e.g. It takes 4 hits to break a Dirt block when wielding a Shovel, but 16 or 17 hits with an open hand.)

This can be observed by repetitively placing Grass on the ground (or a torch on the wall) and breaking it.

The remembered hits are forgotten if the player ...

1. Aims their cursor at a different block, but still through the insta-break block,
2. Breaks the insta-break block with a different item in hand,
3. Hits the behind-block directly, or
4. Hits any block. (Punching the sky / Punching chickens does not reset it.)

Hits aren't forgotten if they come from differently positioned insta-break blocks-, but they do need to be adjacent-. In other words, you can break a single block of Dirt by surrounding it with Grass on all faces and hitting it through each Grass.

These tested positive (each with Oak Leaves behind, wielding nothing):

• Grass
• Tall Grass
• Fern
• Large Fern
• Sugar Cane
• Dandelion
• Poppy
• Lilac
• Peony
• TNT
• Slime Block
• Redstone Dust
• Redstone Torch (caused an explosion b/c of testing order.......)
• Torch

These tested negative:

• Oak Leaves, with Dirt behind, wielding Shears
• Dirt, with Stone behind, wielding a Diamond Shovel enchanted with Efficiency V
• Chickens, with Dirt behind, wielding a Diamond Axe