Materials needed:

• Yarn scraps in different weights can be used, fine, superfine or lace yarns work best
• A hook matching your yarn
• A tapestry needle
• A mason jar

(wire for a suspension, if you want to hang the yar)

Abbreviations used:
ch - chain stitch
sc - single crochet
slst - slip stitch
tr - treble

~ Crocheting around the yar isn´t necessary in the beginning, but you can try it on once in a while to find out if your cozy fits the jar.

Round 1: start with crocheting as many ch as you need to get around the bottom of the jar. Connect with a slst.
Round 2: sc around
Round 3: 2 sc into the second stitch, skip stitch and repeat around
Round 4 : skip first stitch, tr in next three stitches, yarn over hook, put the hook into the skipped stitch and pull the thread through, slst repeat around
Round 5: sc around

Repeat Round 4+5 until your jar narrows towards the brim.

Change to the pattern of Round 3 for as many rounds as you need to reach the brim (as mason jars come in different sizes, it varies). At this point you may want to put the cozy on the jar and crochet around it for a snug fit.

End with one round of sc.

Fasten off and weave in ends

If you want a suspension, use wire and wrap it around the part of the yar where the cap would normally be screwed on and form a loop to hang the jar.