After cleaning and cutting your herbs, set them in a glass of water and cover with a plastic bag, cinching it at the bottom. You may store this in the fridge for a week or more. You may also place a few herb sprigs between sheets of dry paper towel. Place this in a plastic bag and place it in the refrigerator. This will keep fresh herbs available throughout the week.
In order to keep your rosemary fresh for the long haul, you will want to protect it from the cold, dry air in your refrigerator. You can do this with damp paper towels. Simply wrap your rosemary sprigs in a damp paper towel and place them in a zip-lock bag. Seal the bag and place it in the crisper of your refrigerator. This will help preserve the fragrance and flavor of the herb.
If you don't have access to a refrigerator, then place the rosemary in a bowl of water. This will help preserve its scent and flavor.
You can also place the rosemary in some sand or soil at room temperature for about a month. Then plant it when it's time to re-grow more of it!
Finally, if you want to keep some of the rosemary for longer than a month, then freeze it. Once thawed, rinse off any dirt or soil and pat dry with paper towels. The frozen herb will keep for up to a year.
The best way to use preserved rosemary is by adding it to recipes where it's called for. But be sure to remove the leaves before cooking so that you don't overpower the dish with their strong taste and smell.
1-Place dried rosemary in a clean, dry glass jar and fill it about two-thirds full. Leave the rosemary free and not packed so that the oil has adequate area to coat the herbs. 2-Soak the rosemary in a generous amount of extra virgin olive oil. Cover the herbs with oil to keep them from drying out. Let the mixture sit for 6 to 12 months until the rosemary is very soft. 3-Remove the rosemary from the oil and set it aside to cool completely. 4-Put the rosemary into a food processor or blender and process or blend it until it's a fine powder. 5-Heat a half cup of water in a small saucepan over low heat. When the water is warm, remove it from the heat and let it stand for a few minutes. 6-Strain the hot water through a fine-mesh sieve or coffee filter into a bowl or container, pressing down on the rosemary with a spoon to release as much oil as possible. 7-Repeat steps 4-6 with fresh water each time you make rosemary oil. 8-After you've made six batches of hot water, the oil will be ready to use or can be stored in a dark glass bottle. 9-To use rosemary oil, dilute it with a little bit of olive oil before applying to skin.
Fresh rosemary may be kept in the refrigerator for up to two weeks if wrapped in a moist paper towel and stored in a freezer bag. The storage time is shortened in half if the paper towel is omitted. Allowing the fresh herb to stay at room temperature will cause it to wilt and lose quality in a matter of days. Rosemary can also be frozen; simply place sprigs in a zipper-lock bag and freeze for up to three months.
The flavor of rosemary improves with age, so using fresh herbs is always best but if you must store some for later use then wrap them in a damp paper towel and put them in a plastic bag or container. They should keep for up to one month this way.