1.Store the jars in a cool, dark area.  Most (but not all) microbes need heat and light for optimal growth, and aniline dyes will degrade in bright light.

2.Keep jar lids tightly closed when not in use to prevent contamination and evaporation.

3.Add vinegar to the dyes on a regular basis.  Dyes that are rarely used need 1-2 T annually (if you use them; if you don’t use them in a given year, there is no need to open them to add vinegar). Dyes that are used more frequently may need more vinegar: Helen Badulak, who uses hers daily, notes that she adds 2 T of vinegar to her dye jars every other week.

4.Top up with a little bit of water as needed.  The water can evaporate over time, and it is best to keep the dye at a level that will cover submerged eggs completely.

5.Use a separate spoon for each dye. This will prevent transference of colors and contaminants from one dye to another. 

6.Rinse off and dry spoons after use. This will prevent transference of colors and contaminants from one dye to another.

7.If the dyes get debris in them (wax, rust from lids, small amounts of mold), strain them occasionally. Instructions for straining can be found on the following page.