iso-Valeraldehyde (FEMA 2692, CAS 590-86-3) has a pungent, penetrating odor that is quintessentially malty. The most obvious comparisons are with n-valeraldehyde (FEMA# 3098, CAS# 110-62-3) and 2-methyl butyraldehyde (FEMA# 2691, CAS# 96-17-3). All three chemicals have closely related odor profiles, but from my experience, n-valeraldehyde is notably harsher in use than iso-Valeraldehyde. 2-Methyl butyraldehyde is much more interesting than n-valeraldehyde and is certainly a valid alternative, but I feel it is less impactful in most flavor types.
Smelled alone iso-Valeraldehyde is so powerful that it evokes an instantaneous choking reaction, but it would be very hard indeed to imagine a malt flavor without some contribution from this note. In a similar way iso-Valeraldehyde makes significant contributions to many other “heated” flavors, lifting and brightening them. Beyond these very obvious roles this chemical, at more subtle levels, can also provide a very welcome lift to quite a number of “non-heated” flavor categories.
The dose rates given throughout this article are the levels suggested for use in flavors that are intended to be dosed at 0.05% in a ready-to-drink beverage or in a simple bouillon.
Brown Flavors
Malt: iso-Valeraldehyde plays the most important role in malt and malted milk flavors, virtually defining the profile. Levels vary depending on the type of flavor from around 3,000 ppm in malt flavors down to as low as 300 ppm in malted milk flavors.
Coffee: Ideal levels of this raw material also vary widely in coffee flavors. 2,000 ppm is a good level for strongly roasted flavors, adding pungency, but levels nearer 200 ppm still give attractive lift to milder coffee flavors.
Cocoa and chocolate: The best level of iso-Valeraldehyde in cocoa flavors is probably in the region of 1,000 ppm. This level also works very well for dark chocolate flavors, but milk chocolate profiles are better served by around 500 ppm.
Brown sugar: 500 ppm is the best starting level of addition of this ingredient in brown sugar and molasses flavors. At this level it adds useful lift and offsets the heavier notes that so often swamp these flavors.
Black tea: Much more subtle additions, in the region of 100 ppm, work best in black tea flavors, once again adding impressive lift and impact. This ingredient also works in green tea flavors, but plays a less important role.
Vanilla: In a very similar way, the use of iso-Valeraldehyde in authentic tasting vanilla bean flavors at around 100 ppm brightens the profile and adds welcome complexity.
Nut Flavors
Peanut: High levels of this pungent ingredient, in the region of 2,000 ppm, give great lift and enhance the roasted character and impact of peanut flavors.
Hazelnut: Levels of use of iso-Valeraldehyde in hazelnut flavors can vary with the roasting effect that is required but 300 ppm is a good starting point.
Walnut: Moderate levels, around 200 ppm, also work well in walnut flavors, adding brightness and impact.
Savory Flavors
French fries: The ideal level of addition depends to a very large extent on the processing the flavor is expected to undergo, but 3,000 ppm would be a good place to start with a flavor that is not going to be challenged excessively.
Chicken: Chicken flavors run the gamut from excessively boiled to excessively fried. iso-Valeraldehyde has a part to play in most chicken flavors but it has the biggest role in fried chicken flavors, ideally at around 3,000 ppm.
Bread and pizza crust: It would be very difficult to create a good, freshly baked bread or pizza crust flavor without some contribution from this note. 2,000 ppm is a realistic starting level but even higher levels are feasible, especially in pizza crust flavors.
Cheese: iso-Valeraldehyde can make a useful contribution to all of the diverse catalog of cheese flavors but it is especially helpful for cheese varieties where the cheese making process involves some cooking, such as cheddar or Gruyère. 1,000 ppm is a good level of addition for sharp cheddar cheese flavors, but levels as high as 3,000 ppm are even more effective for a toasted cheddar cheese effect.
Beef: There are close parallels between chicken and beef flavors in respect of their compatibility with iso-valeraldehyde. This ingredient is far more at home in fried and BBQ beef flavors than in stewed beef flavors. 2,000 ppm is a good starting point.
Bacon: Bacon flavors present a challenge because of the need to give a fried impact and the indigestion-inducing effects of some of the most widely (over)used bacon flavor impacts ingredients. 2,000 ppm of iso-Valeraldehyde provides considerable impact and allows the other ingredients to be dropped back to more natural levels.
Mushroom: This ingredient is a more important piece of the jigsaw puzzle of cooked mushroom flavors than of raw mushroom flavors. 1,000 ppm is a good starting point.
Lobster: Most types of seafood flavors can be helped by the addition of iso-Valeraldehyde but this is especially true of lobster flavors. 1,000 ppm is the best level to try initially.
Corn chips: The function of iso-Valeraldehyde in corn chip flavors is very similar to the function in French fries flavors, but the best level of addition is rather lower, around 1,000 ppm.
Fried onion: 1,000 ppm also works well in fried onion and fried garlic flavors, enhancing the cooked note and lifting the flavor out of its typically oversweet, heavy profile.
Alcoholic Drink Flavors
Whisky: 500 ppm of iso-Valeraldehyde has a remarkable effect in whisky flavors, simultaneously enhancing the malty effect, brightening the profile and taking the edge off the dominant fusel character.
Rum: Just a moderate addition of this raw material, around 100 ppm, is all that is required to add authenticity to rum flavors, working equally well in light and dark rum profiles.
Brandy and Cognac: Even lower levels, nearer 20 ppm, work well in brandy and Cognac flavors, adding subtly to lift and realism.
Other Flavors
Grape: iso-Valeraldehyde brightens all of the different types of grape flavors, but it is rather more effective in red grape than in white grape styles. 1,000 ppm is a good starting point.
Tomato: This ingredient also serves to lift all types of tomato flavors, working equally well in fresh tomato, such as in tomato puree profiles. 1,000 ppm is also a good starting point here.
Raisin: 200 ppm is a good initial level in raisin and other dried fruit flavors, giving a hint of malt and lifting the profile.
Butter: This ingredient could be helpful in all styles of butter flavors, but it is most interesting in heated butter types. 100 ppm is a useful level.
Peppermint: Even though the best level of addition in peppermint flavors is quite low, around 30 ppm, the brightening effect is very noticeable.