The Fresh Herb Guide

Herbs are the gateway to elevating your cooking from good to great. There is no other ingredient that has a greater effect on your food. But should you use dried or fresh, and when should you use them? Read on to find out.

Herbs haven’t just been an instrument of cooking. For centuries, and into the modern day, herbs have been used as medications. They offer a wealth of antioxidants and may even reduce the risk of cancer and heart disease.

Before we dive into the nuts and bolts of herbs, I want to leave you with the words of the late chef Anthony Bourdain from his book Kitchen Confidential, "that dried sawdust they sell in the cute little cans at the supermarket? You can throw that right in the garbage along with the spice rack. It all tastes like a stable floor. Use fresh!" -Anthony Bourdain. 

And so, with those encouraging words of wisdom, let's begin!

The Science of Flavor in Herbs

Among the water and plant matter that make up herbs is what can best be described as liquid gold: essential oils. These essential oils make up about 1% of the herb and are responsible for the flavor and aroma in our cooking.

Aromas can be broken into three main categories. Top notes, mid notes, and bottom notes. Top notes are what you will detect right away, mid notes are what you will detect afterward, and finally, bottom notes will be detected last and linger longer.

Flavors also have their own categories: Terpenes and Phenolics. Terpenes are light and ethereal but are easily removed by brief cooking. Phenolics define the flavor of the herb and your dish and are significantly more resilient. The flavor of your cooking largely depends on when you add your herbs.

Dried Herbs

In the view of Anthony Bourdain, as well as myself, dried herbs are more akin to sawdust than the herbs they are derived from. But why is that? It all comes down to how they are made. When drying herbs, water is extracted from the herb to make it dry. The broader issue is the essential oils that give herbs their flavor. Oil is more volatile than water, so when drying herbs, the flavor (essential oil) is the first to go. This is why, when you open a jar of dried herbs, it smells of hay or sawdust.

But not all dried herbs are equally bad. Commercial drying removes the most flavor due to its use of high temperatures. Air drying is slightly better, and freeze drying is the best option. Freeze drying freezes the herbs to such extreme temperatures that the water comes off in steam; this process is called sublimation. In each of these instances, flavor is lost; there is no way around it.

Infusing Herbs in Oil

One alternative to dried herbs, and a way to overcome the cost of fresh herbs, is to infuse them with oil. As you know, oil and water don’t mix. So, when it comes to extracting essential oils from fresh herbs, there is no better way than with oil. Vinegar and Alcohol can also be used, but oil is the most effective.

To infuse oil with fresh herbs, you must first bruise them. This helps to bring out the essential oils and increase the surface oil of the herb. Next, gently heat up the oil, add the herbs, and store it in the fridge for a few weeks. This slow steeping allows for the freshest of flavors.

There are some dangers involved in making infused oils. The biggest is botulism. Sugar, alcohol, and acidity (from vinegar), all act as preservatives. Oil has none of these. The air-free environment and lack of preservatives can act as a breeding ground for botulism bacteria. By heating the oil, you aim to kill bacteria in the oil, and by storing it in the fridge, you aim to slow the growth. Herbs pose little risk; however, garlic is of major risk as it provides nutrients for bacteria to grow.

Herbs In Commercial Extracts

If you’ve ever smelt a vanilla bean and asked yourself: hey, this doesn’t smell like my vanilla extract, you’d be spot on. The same holds true for commercial extracts of herbs. Although they are a low-cost way to get “herb-like flavor,” they don’t capture the true essence of herbs. They often taste harsh and don’t capture the complexity and mellowness of herbs plucked from the garden. These highly concentrated extracts may either be made from fresh herbs or may be synthetic chemicals made to simulate the real flavor.

Harvesting & Storing Herbs

Herbs have different flavors depending on when you harvest them. For some herbs, their defensive essential oils will be at their peak at the start of flowering. For others like the fennel sprout, the anise-like flavor will be overpowering and dominate the mature plant, and thus must be harvested early. If you have an herb garden, try harvesting early versus when the plant is mature; you’ll notice differing aromas and flavors.

Once the herb is cut, it will start to secrete hormones that cause deterioration, especially if stored in a closed container. The enemy of storage is air, moisture, heat, and light. Attempting to freeze herbs will cause them to turn black and limp, and although oil is a good option. The best choice is a cool, dark fridge. Store herbs in an open plastic bag wrapped in paper towels to help absorb moisture. Basil, however, requires special care. Since it is from a warm climate, it is best stored in a room-temperature room in a glass of water. Simply fill a glass with water, and put the stems of the basil into it.

I often hear the argument that fresh herbs are so much more expensive than dried herbs. While true, there are ways to overcome the price. Infusing oils is a great way, but another is to grow your own herbs. Although it requires a green thumb, herb seeds aren’t too expensive. Many grocery stores offer basil or rosemary plants you can add to a pot in your house. These tend to be cheaper than the little packs of herbs and will last longer if properly cared for.

Herbs & Cooking

There are countless ways to use herbs in your cooking. Any time a recipe calls for herbs, whether it be dry or fresh, there is no other choice to be made. Always opt for fresh herbs. When preparing herbs, there are two main methods of preparation. One is by cutting with a knife. Always ensure your knife is sharp; a dull knife crushes and bruises the herbs, which leads to a loss of flavor. Another option is to use a pestle and mortar. This method helps to minimize aeration. You may also see recipes call for a food processor when making large batches, such as a pesto. This is very ill-advised; it introduces too much air and significantly damages the flavor.

When beginning to cook with herbs, the aroma chemicals will change. Strong flavor notes will be subdued while the complexity of the herbs and your cooking will increase. Regardless of these changes, there are appropriate times to add herbs. If you are cooking something for a short amount of time, it’s best to ensure they are chopped finely to increase their surface area. If you are cooking something for a long period of time, it’s best to keep herbs in their whole leaf form. In numerous recipes, they will call for dried herbs to be added early on- this is because they are less altered by heat. With fresh herbs, I recommend adding them no sooner than the last 1/3^rd of the cooking time.

Different methods of cooking require using herbs in different ways. For soups, such as chicken wild rice, you can simply tie together your bunch of herbs and add them to the pot. For cooking via sous vide, herbs need only be added to the bag, and cooking can commence as normal. Of course, pestos and sauces can be made in a pestle and mortar. Adding herbs to a dish cooked in an oven or on the stove can be a little more intensive. The herbs can be added to a breading, or more effectively through a brine or marinade. Meat is typically made up of 75% water, and since the essential oils in herbs don’t combine well with water, we must look to other methods. Thankfully, meat contains fat, which allows the essential oils to flavor the meat. However, we must get past the skin to get to the fat. Salt helps to disrupt the skin and allow for easier flavor penetration, but using a syringe to inject the marinade flavored with herbs is the best option. In the oven, the herb flavor is mainly added through the brine and marinade. On the stovetop, you can also add herbs into the pan with butter, and spoon the liquid overtop what you are cooking to help impart more flavor.

Bouquet Garni

One of the easiest methods of imparting herb flavor is through a bouquet garni. This is used in the flavoring of liquids, such as soups. Usually consisting of parsley, thyme, a bay leaf, and celery, it is the gateway to flavor. However, it can and should be altered based on when you are cooking. It is not to be confused with a sachet d’épices, which usually consists of parsley, thyme, bay leaves, and peppercorns. The main difference is that a sachet d’épices has the herbs tied together in a cheesecloth. Think: a tea bag of herbs for your cooking. In order to choose the best herbs for your cooking, I highly recommend using The Flavor Bible by Karen A. Page and Andrew Dornenburg, which you can read about here. What should you not do when making a bouquet garni? Don’t use dried herbs or herbs that have turned colors (brown or black), as this may impart more of a bitter taste. If you aren’t getting enough herb flavor in your cooking, simply allow it to infuse longer or use more.

How to make a bouquet garni

1. Gather ingredients.

2. Lay out the largest/widest herb or flavoring you use, likely a bay leaf or a piece of celery.

3. Place the remaining herbs in the center of the item chosen in the previous step.

4. Hold the herbs together, and wrap a piece of cooking string around the herbs, tying together the ends.

5. Follow your recipe’s instructions for using the bouquet garni.

Herbs, specifically fresh ones, are one of the most useful tools that a cook has at their disposal. Each time I cook a dish that contains fresh herbs for someone, their eyes light up. In a day and age when dried herbs and old spices take up more room in a grocery store than fresh herbs, it seems many aren’t used to the benefits that fresh herbs have to offer. I encourage you to give them a try whenever possible. It will bring your cooking to the next level.

Cheers,

Chef Olson

“The Flying Chef”

Sources

"Kitchen Confidential" by Anthony Bourdain