Fuzzy descriptors are the most frustrating challenge in the never-ending quest to link consumers’ choice of English words to raw materials that we can actually identify and use. Hexyl acetate (FEMA# 2565, CAS# 142-92-7) is very definitely a fruity note, combining attractive pear and banana characteristics.
This simple description does not even get close to saying it all. Hexyl acetate has an additional characteristic that is very hard to define, possibly fresh, possibly juicy, possibly sweet, all somewhat fuzzy. This ill-defined, but attractive, smorgasbord is shared by several hexyl esters and they often work very well together. In the interests of space, we will split them – covering hexyl acetate this month and then hexyl butyrate and hexanoate next month.
Note that the dose rates given throughout this article are the levels suggested for use in flavors intended to be dosed at 0.05% in ready-to-drink beverages or in a simple bouillon.
Apple: Hexyl acetate, clearly, does not bring the instant recognition to apple flavors that ethyl 2-methyl butyrate does, but it is a very welcome adjunct, bringing distinctly greater freshness and juiciness at around 8,000 ppm.
Apricot and Nectarine: Apricot and nectarine flavors are not nearly as ester driven as apple flavors, so the best level of addition is significantly lower, around 1,500 hundred ppm.
Cherry: A good starting point is 1,000 ppm for most cherry flavors, but higher levels can work in profiles dominated by benzaldehyde.
Peach: Noticeably, higher levels are ideal in peach flavors, with 3,000 ppm ideal for juicy style flavors.
Pear: Here the sky really is the limit. At 10,000 ppm, it works very well, but more caricature styled flavors can easily use more, sacrificing strict authenticity for extra sweet, juicy notes.
Plum: The fruity notes of plum flavors should be quite complex. Hexyl acetate, at around 1,500 ppm, plays a key role underlining freshness.
Tropical Fruit Flavors
Açai: Açai flavors are a small, but interesting, category and hexyl acetate can certainly be helpful. A reasonable level of addition is 800 ppm.
Banana: Higher levels work much better in banana flavors, obviously working in conjunction with iso-amyl esters. It works well at 1,500 ppm, but higher levels are also attractive and exhibit only a limited tendency to shift the profile towards pear.
Fig: Just a touch of hexyl acetate, as little as 200 ppm, is enough to add a hint of juiciness to fresh fig flavors.
Guava: The fruity note of guava flavors can be quite complex once you get past the dominant cinnamates. At 400 ppm of hexyl acetate, it reduces the tendency to heavy, cloying notes.
Kiwi: One of the main challenges in formulating kiwi flavors is avoiding too obvious apple notes. Hexyl acetate, at around 800 ppm, is very helpful in this regard.
Mango: Authentic mango flavors should not only emphasize the obvious mango skin notes but also the underlying juice notes. At 500 ppm, hexyl acetate helps in this regard.
Melon: Cantaloupe melon flavors happily incorporate high levels of hexyl acetate, 2,000 ppm and more. The fruity notes of watermelon flavors, on the other hand, are more restrained and are better served by levels in the region of 500 ppm.
Papaya: Papaya flavors have some notes in common with guava flavors and the ideal level of hexyl acetate is similar, around 500 ppm.
Passionfruit: Juicy notes are especially attractive in passionfruit flavors because they work so well in combination with the sulfur notes. Quite high levels, 1,500 ppm and above, are worth considering.
Pineapple: Pineapple flavors are better served by lower levels, nearer 300 ppm, but slightly higher levels can be used in flavors with an enhanced fresh profile.
Pomegranate: I find the character of real pomegranates very attractive, although they can be time consuming to use in cooking. Unfortunately, many pomegranate flavors lack authenticity because the fruity notes tend to be dominated by iso-amyl esters. At 3,000 ppm, hexyl acetate can help propel the fruity note in a more realistic direction.
Blackberry and Raspberry: Hexyl acetate blends very effectively with berry notes in both flavor profiles to increase the perception of freshness at 800 ppm.
Blackcurrant: All styles of blackcurrant flavors can benefit from hexyl acetate additions, ideally at around 1,200 ppm.
Blueberry: Hexyl acetate can help to add juicy character and freshness to the dominant floral notes in blueberry flavors at 600 ppm.
Cranberry: Fresh cranberry flavors, especially those serving at top notes in juice drinks, gain extra juicy character from the addition of 300 ppm of hexyl acetate.
Strawberry: One of the temptations in formulating strawberry flavors is to rely too heavily on ethyl esters and the esters of cinnamic acid. Spreading the net a little wider by adding 1,000 ppm of this raw material can add freshness and realism.
Butter, Fresh: Hexyl acetate is a very minor ingredient in dairy flavors from a quantitative point of view, but it forms an important part of a fruity complex of ingredients adding fresh top notes. An ideal level in fresh butter flavors is 100 ppm.
Cheese, Cheddar: A similar combination of fruity notes is helpful in all cheese flavors. An ideal in cheddar style flavors is 100 ppm, but higher levels can certainly fit in well into blue cheese flavors.
Cream and Fresh Milk: Also, a good starting point in fresh milk and cream flavors is 100 ppm.
Milk, Condensed: Condensed milk flavors can tend towards heaviness and, although 100 ppm of hexyl acetate works perfectly well, there is an understandable temptation to increase the level to 200 ppm.
Bacon and Ham: Just a hint of fruity character lifts the profile of bacon and ham flavors. Hexyl acetate is ideal at 200 ppm.
Elderflower: Elderflower flavors are predominantly floral, driven by linalool, linalool oxide, hotrienol and rose oxide but a strong, fresh fruity note is very helpful to round out the profile. Hexyl acetate can provide this at 2,000 ppm.
Grape, Concord: At 500 ppm, hexyl acetate adds nice freshness to Concord grape flavors, offsetting the mustiness.
Olive: Olive flavors benefit from a hint of fruit character and 200 ppm of this ingredient is ideal.
Rum, Brandy and Whisky: All spirit flavors are lifted by subtle additions of hexyl acetate, typically around 50 ppm, although higher levels, nearer 300 ppm, are to be preferred in whisky flavors.
Seafood: Fruity notes in fish and seafood flavors may seem like a strange idea but they can work, especially in crab flavors. Start of generally with very low levels, but crab flavors can happily absorb 300 ppm.
Tea: Hexyl acetate is also helpful in all tea flavors. The best level in black tea flavors is around 100 ppm, but green tea flavors are better served by 200 ppm.
Tomato, Fresh: Hexyl acetate is only of very minor interest in processed tomato flavors, but it lifts fresh tomato profiles subtly at 50 ppm.