First time dying

I tried my hand at dying the other day. My mother-in-law gave me some white yarn to try it out with. First I wound the yarn around a niddy noddy and made two skeins of yarn.

So after skeining the yarn I heated it up on the stove in some water as not up shock it (at the time I thought I had wool,and wool felts if the the temperature changes to quickly. I have since realized I have cotton).

I made the dye bath with used coffee grounds that I boiled for a hour. After straining the coffee grounds I put the skeins of yarn in to dye. I simmered them for a hour and then I pulled one of the skeins out and let the  other sit over night to see if I got a darker color.

The one that sat over night is slightly darker, but it's hard to tell.

Top is yarn in bath 1 hour, bottom is yarn over night, right is original color.