Aroma associated with fresh-cut grass. Reminiscent of a pasture or green field. Often times just called by the general term "green".
Grassy aroma is usually attributed to aldehyde compounds such as geraniol or hexanal. These compounds usually come about through the secondary oxidation of lipids.
Aroma associated with fresh herbs. Encompassing general herbs and spices.
Herbal aromas and flavors come from a large number of compounds and their combinations. Structurally aromatic compounds, esters, acids, aldehydes, and combinations thereof makeup a vast amount of the resultant aromas in herbs.
Aroma associated with a "green apple" aroma. Often elicits a puckering sensation in the mouth.
This compound is often generated by microbial activity, such as the lactic acid bacteria cultures used in cheesemaking. Examples include:
Aroma concerning fruity aromas and flavors in cheese. Similar to pineapple, strawberry, and other fruits. Sometimes described as generic "fruity breakfast cereal"-type aroma.
Fruity aroma, much like many of the other complex aroma types in cheese, come from a variety of compounds. In many cases, esters are generated from enzymatic activity in cheese resulting from cultures or endogenous compounds in the milk. This class of compoudns are formed by the reaction of an acid with an alcohol compound, therefor ester formation could happen spontaneously without culture activity. For cheddar, high amounts of fruity aroma is considered a defect by professional graders.
Aroma associated with roses or other flowers.
Rosy/floral aroma in one study was attributed to phenethyl alcohols, and the related esters and aldehydes.
Aroma associated pine trees. Reminiscent of rosemary or other resinous herbs.
Related to herby aromas, piney aromas are usually attributed to terpene compounds such as geraniol or prenol. Usually introduced to cheese by it's wrap or aging conditions. The mechanism through which these compounds are formed in cheese is not yet fully understood.
Aroma associated with members of the alium family: garlic, onion, etc.
When a cow's diet consists of high amounts of aliums, the main aromatic components of those foods can carry over to the milk and then into the final cheese. The compounds responsible for these aromas start their life as sulfur-containing amino acids, like cysteine. Various enzymatic activity within the vegetables create volatile aromatic compounds such as thiosulfinates.
Generic term describing the presence of a flavor/aroma that doesn't belong.
Aroma associated with generic nuts. This term is hard to define due to the wide variety of nuts and their associated flavors, some of which differ greatly.
In the case of swiss cheese, the nutty aroma may come about from propionic acid production due to Propionibacterium freudenreichii subsp. shermanii. Other compounds, like amino acids, are also produced leading to nutty flavor. Nutty notes from cheddar are a little more complicated.
Aroma associated with fresh mushrooms. Umami-like meaty aroma.
Unlike many aromas in cheese, this one can be attributed to just about one key compound, mushroom alcohol. This compound comes about through the metabolism of the white mold on the exterior of the cheese.
Another generic term much like "clean". Usually used for fresh cheeses.
Aroma/flavor associated with fresh milk or milk-fat. Reminiscent of cream or whole milk.
Milky aroma is usually attributed to lactone compounds. These compounds come about through reactions of the fat in milk. See this study for potential mechanisms in gouda cheese.
Aroma associated with butter. Reminiscent of microwave popcorn.
One possible source of buttery aroma is from the compound diacetyl. Usually comes about from microbial activity or breakdown of compounds in cheese.
Sweet can mean a few different things when used in a cheese context:
Aroma associated with old milk.
Different from acid, sour refers to acidity that is vinegary or citrus-like.
Usually comes about from microbes producing various types of acids.
Aroma associated with cooked milk. Slightly sulfur note, like scalded milk.
Cooked notes from cheese are usually due to the formation of sulfur linkages in the milk proteins. Whey proteins unravel with high heat and can form sulfur-sulfur or sulfhydryl linkages.
Similar to cooked, only to a greater degree.
Flavor similar to caramel or cooked sugar. Sometimes referred to as "butterscotch"-like
Some products of certain microbial metabolisms may have caramel flavor or perhaps some products of maillard browning reactions that are going on in the cheese. Furan-type compounds like furaneol and homofuraneol are thought to contribute to caramel flavor.
Aroma associated with cows, barns, etc.
Cowy/barny is thought to be casued by cresol-type compounds. This aroma's complexity makes it hard to single out specific compounds. The exact mechanism is also hard to fully elucidate, but it is most likely microbially related.
Aroma associated with goats. Literally smells like goats.
Goaty aroma can usually be atrributed to specific fatty acids that are found in high concentration in goat milk. Specifically medium-length and branched fatty acids.
Aroma associated with sheep.
Similar to goaty aroma. Fatty acid profile seems to be part of the sheepy aroma as well as phenolic compounds, other compounds (More research needs to be done to identify the root cause)
Aroma associated with a horse blanket. Reminiscent of a generic animalic mustiness.
Aroma associated with cat urine. Very strong and reminiscent of a sulfur-like aroma.
Catty aroma is often lumped in with sulfur aroma due to similar chemistry of causitive compounds. A compound know as "cat ketone" is thought to be a cause of catty aroma.
Aroma associated with sweat or body odor, sometimes called "sweaty sock". The term sweat is often used interchangeably with "cheesy" when describing the aroma in other foods.
Sweat aroma is usually attributed to wide-range of compounds. One such compound is isovaleric acid. Found in sweat and often described as having a "vomit" aroma.
Lanolin refers to the wax secreted by the sebaceous glands of wool-bearing animals. Reminiscent of a dirty/fatty aroma.
Lanolin is made up of long chain fatty acids.
Aroma associated with hay or straw. Commonly known as the "Feedy" defect.
Unclean practices could cause hay to enter milk supply and flavor could possibly carry over into cheese.
Drying or puckering sensation in the mouth.
The causes of astringency can vary greatly. In some cases metal ions could give astrigency, in the case of salt-replacing cheese. More information can be found here. High levels of acidity can also cause this.
Prickling or "spicy" feeling in the mouth. Literally feels hot or burning.
The actual mechanism of the burn sensation is not fully understood. Histamine-type compounds found in the cheese are thought to be a leading cause. Free fatty acids can also cause a prickling/burning sensation. Lipase effects are also being studied.
Aroma associated with soap. Think ivory soap.
Soapy aroma/flavor is usually caused by medium and long-chain fatty acids.
Aroma associated with wax.
Long-chain fatty acids once again. Heavily saturated.
Aroma associated with baby vomit. Often called "rancid" or "piquant".
Comes from the fatty acid butyric acid. Lipase cleaves off fatty acids from triglycerides.
Aroma associated with sulfur, boiled eggs, struck match.
Sulfur is the hallmark of some aged cheddar cheeses. Sulfur is dervied from sulfur-containing amino acids. Microbial action (or perhaps enzymes) produce sulfur compounds such as: hydrogen sulfide, methyl mercaptan, etc.
Aroma associated with ammonia.
Ammonia and ammonia compounds can be a result from microbial metabolism and protein break down.
Often confused with acid. Some people have a higher threshold for the detection of bitter, leading to the term "bitter blind". Bitterness is often caused by the presence of "bitter peptides" that are a result of protein breakdown.
Sweet can mean a few different things when used in a cheese context:
While sugar is rarely added to cheese, sometimes sweet taste is present. In the case of swiss cheese, it is thought the amino acid proline is responsible.
Basic taste. Meaty, savory, etc.
Microbial metabolism and protein breakdown can result in umami-tasting compounds, like the amino acid glutamate.
Catch-all term to describe a foreign taste in cheese.
Tangy-ness associated with having metal in the mouth.
Common in instances where potassium chloride (KCl) is being used to lower sodium contents.
Aroma of beef broth. Sometimes referred to as meaty. Similar to umami.
Aroma of roasted vegetation and meats. Similar to brothy, but often associated with cooked nuts.
Roasted aroma is usually attributed to Maillard browning products and their derivatives. Origins still aren't completely clear, microbial metabolism is also a likely suspect.