When people talk to me about herbs I get a few common herbal questions regularly. I tend to ask them in return about the quality of the herbs they’re using. I usually get a confused look in response. The quality of herbs you’re using is often overlooked but incredibly important.

What do I mean by herb quality? Medicinally potent, properly harvested, processed and stored herbs that are preferably not older than a year. The length of time a properly stored herb or spice is stored affects the potency.
Things That Affect Quality
Long-term storage in a warehouse without climate control can negatively affect herbs. Harvesting at the wrong time of year affects the strength of the medicine. Improper processing, such as inadequate drying before packaging, can lead to mold growth. This is why there are Good Manufacturing Practices and other consumer protection laws.

Quality Control
As an Herbalist I focus on easy to grow herbs, because I like to know the history of the herbs I’m using. When I grow my own I can control the quality because I am harvesting, drying, processing and storing my herbs.
As a “whole herb” type of herbalist, growing my own gives me the flexibility to use different parts of the plant that may not be commonly available. Ie: You can buy fresh or dried ginger and turmeric roots almost anywhere, but I have yet to find the leaves of either.

I store my homegrown herbs as whole as possible to retain their potency. They’re in glass containers away from any heat sources and sunlight. Each container is labeled and dated so I can keep track of how quickly I use them. I try to keep the containers small to minimize air space in them. If I have a large amount, I will fill another smaller jar for frequent use.
If you’re eyeing your spice rack by now and wondering if your herbs are still potent, there’s an easy way to tell.
Trust Your Senses
Look at it. The dried herb should be close to the same color as it would be if the plant was still alive. If green herbs like basil, thyme, and rosemary are tan, compost them. (Of course if you grow a purple basil variety or a variegated thyme, adjust your expectations accordingly.)
Use your nose. The herb should have a strong smell when you open the storage container. If you open cayenne powder and have to stick your nose into the container to get a hint of it, relocate it to the compost.

Take a small taste. The herb should have a strong taste. Note: I didn’t say pleasant! Some herbs can be intensely bitter or unbearably hot. If you have to use half a jar to get any flavor, it’s time to put them in the compost bin.
You can use the visual principle to determine the potency and quality of many dried herbs you purchase in stores. I highly suggest making this potency checklist a routine habit when cooking.