Condiment/Spread

Our Test Kitchen’s Favorite Way to Use Up Leftover Herbs

July 10, 2018

In the restaurants I’ve worked at, “green” is a colloquial term for any herb-infused oil. As in, “Hey, my puree is dull, do you have some green to share?” If your spring onion soup looks a bit pale, “green” will save it. Have five minutes to come up with a special, and it needs a little pop? Drizzle that green, baby.

In a penny-pinching industry where product cost can affect the entire restaurant’s bottom line, there is no room to waste herbs. That's why many New American restaurants often turn them into herb oil. It’s one of the most eye-catching items one might come across in the walk-in pantry.

Drizzle that green, baby. Photo by Bobbi Lin

You can make this, too, especially when you have a few random herbs getting limp in your refrigerator. With a little neutral oil, a pinch of salt, and about 30 minutes, you’ll reap the rewards for weeks to come.

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Now, I know “blanching” can send even the most seasoned home cook into a dither. Yes, it adds a whole other pot to your dinner preparation, but blanching the herbs—that is, dunking the herbs in boiling salted water and then immediately in ice water right after—is essential for color. If what you want is a GREEN thing, you must blanch and shock. You will end up with a little ball of the herbs after squeezing all the water out with a towel or paper towel or your hand. Throw it in a blender.

As for what herbs you can use, any soft, fresh herb will work (basil, parsley, chives, oregano, dill, or cilantro, for example). What maximum green with a mild taste? Use parsley, which is not as punchy as basil or cilantro. (Pro tip: Try making a combination of parsley and mint, using 60% parsley. Your ricotta-topped toasts will thank you.) Want to use up all your old herbs? Throw them all in. Experiment, tasting as you go. Get crazy. Once you’re done blending, strain the puree through cheesecloth or a strainer. This takes about 30 minutes. When you're done, save the oil in a jar or a cruet and use generously.


Put This On Toast & Add "Green"

Because you blanched, this herb oil will not lose its color after a few days, but will stay green for at least a month. However, a base rule with leafy herbs—unlike woody herbs like thyme or rosemary—is that they are used for finishing. Adding heat saps the flavor, so you want to don’t want to cook food in this oil, but simply top off foods, like roasted vegetables or crostini or pasta or vinaigrette or grilled meat (...), with your emerald green herb oil.

What's going in your emerald green herb oil? Let us know in the comments!

9 Comments

Sonj August 17, 2018
Chimichurri is also my favorite way to use up herbs - blend with fresh garlic, EVOO, salt, and an acid - lime/ red vinegar or both - possibly small shake red pepper to taste - my family gobbles this up on fish, shellfish, meat, potatoes, rice, veggies.
 
Cyn July 12, 2018
Excellent article, Taylor! I never knew this - can't wait to try it! I have an abundance of fresh herbs right now, and was just thinking what I could do with them!
 
Elyse L. July 12, 2018
I really enjoyed this charming article that showed me something I never knew about leftover herbs. I always have so many left over and it hurts to throw them out. Great information
 
isabel H. July 11, 2018
After reading the food safety comments, I have another suggestion for using up leftover herbs: make a simple pesto. Put leaves and soft stems in food processor, and while machine is running add enough olive oil to make a thick but pourable mixture. Season as desired. Pour into ice cube trays, freeze, pop out and store in plastic bags in freezer, ready to add to soups, sauces, dips, or whatever needs a little punch of herb flavor.
 
Kellye K. July 10, 2018
I always feel so guilty tossing my leftover herbs, can’t wait to try this. <br />Especially on ricotta toast!? Yum!
 
Morgan23 July 10, 2018
Really great article!!! I never know what to do with my leftover herds and hate wasting food. I can’t wait to try this with my summer dishes. Great advice
 
Nancy July 10, 2018
An idea to use up extra leafy herbs is great! But I'm worried about the safety of an herbed oil one month in the fridge. From what I remember years ago, when I learned to make infused oils & flavored vinegars, common advice is a few days or max 1-2 weeks for herbed oils, and a couple months for herbed vinegars. <br />A quick web search brings this example of current advice from an extension service at Colorado State recommending max 3 days in fridge for herbed oils, or store longer in freezer.<br />Your comments?<br />http://extension.colostate.edu/topic-areas/nutrition-food-safety-health/flavored-vinegars-and-oils-9-340/
 
Josh C. July 10, 2018
Hi Nancy, I looked at the link you shared. I believe that if the herb leaves are raw, then the oil should be thrown away after three days. However, because the herb leaves are dipped in boiling water and then a lot of their moisture is squeezed out, I believe that this particular herb oil can last significantly longer in the refrigerator. <br /><br />The risk of botulism comes from raw vegetables or herbs or garlic, sliced and stored in oil (and this is especially risky if the oil is stored at room temperature).<br /><br />I am not a food safety expert, and I am always open to hearing feedback from others. If you have an opinion that differs from what I have just written, please let me know, because I do not claim to know everything on this topic. That being said, I have been a professional chef for years, and this is what I believe to be true. <br />
 
Nancy July 10, 2018
Josh -<br />Thanks for the thoughtful response and the distinction between cooked and fresh herbs used in flavored oils; also the bigger caution about botulism danger from garlic oil.<br />Because of the warnings, I stopped making the garlic oil as couldn't use it up fast enough. <br />And make the herb oils only when I know the meals planned will use them up quickly.