How to Substitute Fresh Herbs for Dried Herbs
Most herbs can be used either way, but there are exceptions
If it's the middle of summer and you've got plenty of fresh herbs growing in your garden, you probably want to use them while they're fresh. But what if your recipe calls for dried herbs instead?
Fortunately, it's usually pretty simple to substitute fresh herbs from your garden for the dried herbs called for in your recipe. You'll wind up using more of the fresh herb, because in fresh herbs, the flavor isn't as concentrated as it can be in dried herbs.
Here are some general rules you can follow for the vast majority of herbs you might grow in your garden, plus specific ideas for individual herbs that may be more or less pungent when they're dried, and so might require slightly different substitution ratios.
General Rule to Substitute Fresh Herbs for Dried Herbs
For most herbs — even unusual ones such as orange thyme, ginger mint and winter savory — you generally can follow a rule of thumb that calls for tripling the amount of dried herbs called for in any recipe when using fresh herbs.
For example, if your recipe calls for a teaspoon of dried oregano, you would use a tablespoon of fresh oregano in its place. If the recipe calls for half a teaspoon of parsley, you would need to use one-and-a-half teaspoons of fresh parsley.
However, there are some common herbs where this ratio doesn't work well. Fresh oregano, for example, can be quite strong, and may taste metallic. Therefore, you should tread carefully when substituting it for dried oregano in a recipe, since you most likely won't need anywhere near three times as much fresh oregano to get similar results.
Knowing When to Substitute Herbs
Some herbs work best when dried, while others need to be fresh to taste "right" in certain recipes.
Fresh basil, for example, is the main ingredient in pesto, a green Italian sauce that's made with olive oil, pine nuts, garlic and cheese in addition to the basil. To make a good pesto, you can't really substitute dried basil for fresh — the pesto just won't taste the same.
On the other hand, many chefs believe that dried oregano tastes better than fresh, and works more effectively in dishes such as tomato sauce and Greek roasted potatoes. Thyme also tends to work at least as well in recipes in its dried form as it does when it's fresh.
The Bottom Line
When making any substitutions to flavoring agents such as spices in a recipe, it's always a good idea to go slowly, just in case the taste becomes overpowering.
In the case of fresh herbs, you can start with one-and-a-half times the recommended dry amount, and then move up from there, tasting as you go. If you follow this approach, you're likely to find a ratio that works well for your particular recipe and your particular herb crop.