Adding yarn in crochet covers any moment you need a new strand attached, whether from running out of a skein, switching colors, or repairing a damaged section. I use the same core technique for all three situations, just with different knot choices depending on visibility needs. This guide covers the general approach.
The General Approach
Work your last stitch with the old yarn until two loops remain on the hook, then finish that stitch with the new yarn instead. This single technique underlies joining a new skein, changing colors, and repairing a torn section, with only the finishing knot choice changing based on whether you need the join to be invisible.
Frequently asked questions
Is adding yarn the same process for a color change and a new skein?
Yes, the core stitch mechanics are identical. The difference is mainly in where you plan the switch and which finishing knot best hides the join for your specific situation.
Need the specific same-color join method?
See the magic knot method for an invisible same-color join.