I hate to admit it but, one of my least favorite knitting tasks is joining yarn!
Happily, there is an alternative to knotting and weaving as you go. It's called wet splicing. In my opinion, it is one of the best joining techniques ever and I use it often. The wet splice is easy to accomplish! You need no special tools except your hands, a safety pin and a bit of water. It works on any wool or wool blend that are NOT listed as superwash wool. The superwash coating that protects your wool in the washer will also prevent the strands from gripping together.
How-to Wet Splice Yarn
Step 1: Split the strands of both the old and new yarn about 4 inches in.
Helpful Tip: You can either use a safety pin or your fingers and gently pull the strands apart.
Step 2: Overlap the strands of both old and new yarns.
Step 3: Using plain tap water, wet the combined strand.
Step 4: Lay the strands between your palms and rub your hands together briskly.
The combination of the heat and friction in your hands will cause the wool fibers to grip each other and weld both strands together!
Step 5: Check your weld by tugging on either end.
Voila! You are done and ready to knit on!