Clicking a recipe in the new recipe book that you can make and then click one you cannot and back will increase the amount in the recipe grid by 1 each. Shift clicking with the same back and forth clicking will double it to max 64 block stack for the items.
MC-115482
Duplication within the new Recipe book system
Resolved
Duplicate
0
I am having this happen, too. I also had the boat recipe just appear out of nowhere while I was trying to make a sword and pickaxe. I didn't even place the wooden planks in the formation of a boat and it just appeared in the book.