Infused With Flavor

By Christopher Warsow, Contributing Editor

Although there is no legal definition in the food industry for an infusion, many informal ones are out there. It just depends on whom you ask. From the culinary sense, an infusion is adding a desired flavoring agent, usually plant-derived, to a steeping liquid. From a flavor manufacturers standpoint, an infusion is the method of extracting a flavoring material from any solidwhat we commonly think of as an extract.

Avenues to flavor

From my perspective, infusion is a passive form of extraction. For instance, adding rosemary and garlic to olive oil and leaving it on the counter under ambient conditions creates an infusion. Expediting this process with heat or mechanical methods forms an extract.

According to the Flavor and Extract Manufacturers Association (FEMA), Washington, the several methods of making an extract should be based on the solubility of the substance that needs to be extracted. Most solvents can be classified as polar (alcohol) or non-polar (oil). If you remember your high school chemistry, like dissolves like. That means paprika oleoresinan oil-soluble material will readily dissolve in oil, but will not dissolve in water.

A typical commercial extraction of a spice volatile would be to grind the spice and dissolve and extract it into hexane. The hexane is distilled off and recovered to be used again. The resinous material that remains is the oleoresin, which can be used to flavor food products.

One of the first examples of infusion that I learned in culinary school was the first step in making a béarnaise sauce. According to The Professional Chef, the Culinary Institute of Americas textbook, the first step is to make an infusion of peppercorns, dried tarragon and tarragon leaves into tarragon vinegar. I found this recipe unique because it calls for making an infusion with an infusion (the tarragon vinegar), thereby adding a powerful burst of flavor to the sauce. The tarragon vinegar is made by simply placing fresh tarragon into 30-grain distilled white vinegar brought to just below the boiling point, sealing it in a sterilized glass bottle, then allowing it to cool to ambient temperature. The mixture is heated to kill any bacteria that may be present on the tarragon. It is allowed to sit in a cool, dark place for at least three weeks. Then, for this béarnaise preparation, the tarragon vinegar is further infused with tarragon and peppercorns. The resulting double infusion is then added to the egg and clarified-butter emulsion at the end of cooking to flavor the sauce.

The rate of extraction can be modified by the temperature of the extraction medium (solvent). A good visual example of this would be to put annatto seeds into cold cooking oil and hot cooking oil. When they are dropped into the cold oil, not much happens. However, when heated oil is used, the color change is immediate. Only hearty compounds can be infused this way.

In a traditional Caribbean sofrito (a concentrated sauce thats used as a flavor base for other dishes), salt pork is rendered, and annatto seeds are heated in the lard until it is richly colored and highly flavored. The annatto seeds are then strained out. This oil is then used to cook the components of the sauce.

If you tried to make an infusion of violets in this manner, you would fry the flower, and all of the desired floral components would flash off. A slow and cool infusion in alcohol is necessary for this infusion. To make an alcohol-based violet infusion, start with a mixture of 70% ethanol and 30% water, or 140-proof neutral grain spirits, and add the violets. The violets should be macerated to facilitate maximum extraction. Put the mixture in a clean glass container and allow to steep for two to three weeks in a cool, dark place. Strain the macerated flowers and dilute with more water to taste for use in beverages and cocktails.

Other methods that do not involve a solvent are commonly referred to as infusion. When a vanilla bean is placed into a canister of sugar we say the sugar is infused with the flavor of vanilla. When a chef gently smokes a chicken over wood, would the chicken then also be infused with the smoke?

Infusions can be made with any number of solvents, but the flavors that you extract will be different. If you made an infusion of basil in separate solutions of vodka, oil and water, each one would have distinct characteristics. The reason behind this is that each of the chemical components that give basil its characteristic flavors has different solubilities in different solvents.

The infusion of basil in alcohol would highlight the grassy, green notes of the basil, reminiscent of freshly cut grass. The oil infusion would be high in the earthy and woody notes of the basil, whereas the water infusion would be highest in the leafy-type notes that are characteristic when tearing a basil leaf and smelling it.

The aroma of these three different infusions would display varying characteristics, as well. The alcohol and water infusions will have a stronger aroma because of the characteristics of the solvents and the interaction it has with the solute (dissolved substance). Alcohol and water infusions are more common for beverages, where you need a high initial aroma that quickly dissipates.

The volatility of the compounds being extracted comes into play if you plan on cooking with an extract or infusion. Any long, high-heat cooking process will flash off or volatilize the substances that give flavor. Many of these compounds are delicate and are easily destroyed. For instance, when you add vanilla extract to a baked product, some of it is lost during baking. If you put this same amount of vanilla extract into a doughnut batter, then fried it, much more vanilla would be flashed off because of the higher heat it is exposed to.

As previously noted, the solvent used as the basis for infusion has much to do with the infusions resultant characteristics. Oil-based infusions are oftentimes more robust than alcohol- and water-based infusions, since oil-based extractions are higher in larger, non-polar compounds that are less likely to volatilize under non-frying cooking temperatures. Oil-based infusions work best when the product is subjected to heat. A basil oil would work much better in a bread application than a water-soluble one. Water- and alcohol-based infusions work best when the final product is not heated. This would include products like mixers and bases for cocktails, as well as ice cream. Alcohol-based infusions are higher in the top notes of the infused product.

Spirited concoctions

Flavored spirits are popular right now, but few use true infusions or extracts to produce the product. It is my opinion that there is a difference between an infused spirit and a flavored spirit. An example of an infused spirit would be a true absinthe. During manufacture, herbs are placed in a distilled spirit and allowed to steep. The flavorants are directly infused into the alcohol. The spirit is then distilled again.

However, most spirits these dayseven those labeled as infusedare made with extracts or flavors. Marko Karakasevic, master distiller, Charbay Distillery, St. Helena, CA, uses extracts that he makes himself from fresh picked fruit when making his flavored vodkas. He has strong feelings against using natural flavors in his products, preferring to use extracts that are made in-house.

Karakasevic says that some of his favorite fruits to derive extracts from are blood oranges, Meyer lemons and pomegranates because they grow so well in California. He believes the best extracts are derived from the freshest fruits, which he hand selects. He is a 13th generation distiller and has been continually modifying the extraction methods that have been passed down from generation to generation. He jokingly refers to his extraction methods as ASET, or ancient Serbian extraction technologies.

Infused opportunities

Infusion is a widely used cooking preparation. The basis of many Japanese dishes is dashi broth, which is a water-based infusion made with kombu and bonito flakes. This infused broth embodies the word umami.

Many commercially available flavors use extracts for their basis. When an extract is made, sometimes some of these delicate volatile aromas can be destroyed. It is the job of a trained flavorist to know how to rebalance these flavors to give the notes that a customer is looking for. Some of these aroma chemicals come from extractions of other natural materials.

In a lose translation of the word infused, a protein marinade would also be an infusion. When we make corned beef, we are infusing the pickling spice into the meat. Like an infusion, we discard the substance that we are drawing the flavor from (the pickling brine) and consuming the solvent (the brisket).

One noteworthy infusion Ive seen on menus lately is the use of a ginger-infused oil to garnish carrot soup. The ginger adds a sharp, spicy contrasting note to the rich sweetness of the roasted carrots. Making ginger oil would be very similar in method to making the tarragon oil mentioned earlier, simply adding sliced ginger to the oil and allowing it to sit at ambient temperature.

One of my favorites is clarified butter that has been infused with the flavor of roasted shellfish shells. For this preparation, the shells are roasted then slowly poached in clarified butter to extract all of their essence. This butter can then be used to poach seafood or drizzle over finished dishes.

Other infused products are currently available. There are ready-to-use broths infused with herbs, as well as myriad high-end cooking oils and just as many vinegars. But, what other infused products could be developed?

A few concepts that would be interesting would be to infuse whole shell eggs with herbs. Imagine a nice sunny-side up quail egg with the aroma and flavor of chive and thyme perched on top of a mix of spring greens that have been dressed with a lavender-infused vinegar. Top that with a sprinkle of crunchy bacon infused with hickory smoke and thats three infusions in one dish.

Christopher Warsow is corporate executive chef for Bell Flavors & Fragrances, Northbrook, IL, and a member of the Research Chefs Association. For more information, visit bellff.com.