Here is an excerpt I found on proper storage of spices:
"Spices do not age well and have surprisingly short shelf lives. Whole spices and herbs have about twice the life of their ground counterparts.
Whole leaves and flowers are good for a year; once they are ground, they are good for about six months
. Whole seeds and barks last two years, once they are ground they are good for one year.
Whole roots last more than two years, once ground, one year
. If you find that you have to increase the amount of a given spice in a dish to make it "come out right" then the spice is telling you that it is old and has lost its potency.
When spices get old, one of two things occurs: they lose potency or they become bitter. In either case, old spices can be worse than no spices because they can have an unpleasant impact on the outcome of your meal. Look for the loss of color, or color fading as a good indicator that a spice might be old. If the spice does not have a fresh odor or taste, it may be time for it to be replaced. If your spice begins to cake up, it is a good sign that moisture has gotten to it, and it should be replaced.
The way spices are stored and handled have a lot to do with how long they will last. Proper storage will not improve the life of spices, but improper storage will decrease their effective life.
Spices need to be stored in dark dry locations. Never store spices in the refrigerator
, as the high humidity is harmful. Similarly, never hold a container of spices over an open container on a hot stove, as the moisture and heat rising from the open containers can get into the spices remaining in the container. Similarly, always use a clean, dry spoon when scooping spices out of a container.
Store your spices in a cabinet or in a spice drawer. Cabinets are acceptable because they mostly keep the spices out of the direct light, but cabinets are not efficient places for spice storage unless one uses an in-cabinet rack to provide easy access and to minimize wasted space. Well-designed spice drawers are an excellent choice as they keep spices away from the heat, light and moisture that are commonly found in kitchens. In addition, spice drawers lend themselves to the user of screw-cap jars with rubber seals that will help further protect the contents.
As with cabinets, putting spices in a pantry keeps them out of the light, but can be a potentially inefficient use of the space. A pantry is a good place to use a counter top spice rack, or you can mount one to a wall or the inside of the door. An alternative idea is to put the spices on a small step shelf, which will help make the smaller containers easier to organize and see.
Counter top and wall-mounted spice racks are attractive and popular, but they are not ideal for storage because they expose the spices to light, especially sunlight. Yet, they are very popular, and some kitchen designs make them a necessity. If you decide to use a freestanding or wall-mounted spice rack, pay particular attention to where it is located. Keep it as far away from the sink and stove as possible, so as to minimize moisture. Try to locate it where it never gets hit by direct sunlight. If you can minimize the amount of direct fluorescent light it gets, so much the better.
Taking these basic precautions can ensure that your rack not only looks attractive and compliments the kitchen, but it also protects your investment in spices."
Hope this helps!