When don't you need it? when should you add it? where did the red go? can you reuse the dyebath? will old bottles still work?
Q. I'm using Kool-Aid, do I need vinegar?
No, the citric acid in drink mixes will bond the food color to your wool, nylon or wool blend yarn.
There is enough citric acid that you can add a few drops of McCormick (or other food color drops) and a dab of Wilton frosting gel and it still works.
Here is a video on this.
Q. When should I add the vinegar?
For most colors, it's personal preference.
Soaking in water with vinegar produces a solid color. Adding it quickly to a hot dye bath can make a more mottled yarn.
The exception to this, is the next question.
Q. When I am using some colors of Wilton, the dyebath gets less red. Why does this happen?
This photo shows two jars of Wilton royal blue, the left has a teaspoon of vinegar added, the right is plain water.
And the color of the dyebath is the color the yarn will be. There is no easy way to get the red to come back.
Other Wilton colors that shift to less red are: burgundy, violet, and delphinium blue. Copper shifts slightly.
These colors contain red but don't shift: aster mauve, black, juniper, and Fairies blue.
The easiest way around this problem is to mix up a dyebath with the food color and plain water and let the yarn soak overnight. Heat the yarn in the bath to 160 degrees F (72 C) and slowly add the vinegar.
Then raise the temperature to 180 degrees F (82 C), so the food color will bond to the yarn.
Overnight soaking allows the red to bond to the yarn, not the dye pot.
Q. Once I have finished dyeing for the day, what can I do with the water?
The dyebath is safe to pour down the sink.
Or you can save it for reuse.
The food color will be gone, but the acid level of the water remains the same.
I keep three jugs of exhausted bath:
1 = red, yellow, and orange
2 = green
3 = blue (that doesn't have red3).
And you don't have to wonder if the amount of acid in the water is enough to set the color. If the dyebath worked the first time, it will always work.
A word of warning: the dyebath will eventually get moldy.
If you sterilize the storage jars, and boil the dyebath, you will get a few extra days.
Q. I have a bottle that is a few years old. Will it still work?
This is unknown.
While lemon juice will lose its acidity, no one seems quite sure about vinegar.
My oldest jugs are less than a six months old, because I use so much.
But as my DH says "if you're using expensive yarn, spend a few bucks on a fresh bottle."
Q. How much vinegar do I need?
This depends on the acidity of your tap water and the color you are dyeing.
I use a teaspoon per 8 ounces water for reds and yellow and a tablespoon for blues.