Popcorn stitch (PC): Yarn over, insert hook in indicated stitch or space, yarn over, pull up a loop (yarn over, pull through 2 loops) twice (first double crochet made), (yarn over, insert hook into same stitch or space, yarn over, pull up a loop, [yarn over, pull through 2 loops] twice) 4 times (4 more double crochet made), remove hook, insert hook through first double crochet made from front to back then through the loop once again, pull the loop through the first double crochet stitch.
Note: This stitch has many variations, be sure to check the special stitches description in your pattern before working the stitch.
Popcorn Stitch
Yarn over
Insert hook in indicated stitch or space
Yarn over
Pull up a loop
Yarn over
Pull through 2 loops
Yarn over
Pull through 2 loops (first double crochet made)
Work 4 DC into same stitch or space
Remove hook
Insert hook through first double crochet made from front to back
Then insert hook through the loop once again
Pull the loop through the first double crochet.
Pro Tip: While Puff and Bobble stitches are typically worked only on right side (RS) rows, you can work the popcorn on every row and still have the texture appear on the right side. A back popcorn stitch is worked the same way as above, but when you remove the hook and insert into the first stitch, insert the hook through the first double crochet from back to front (rather than front to back) and the stitch will pop out on the back side of the work.