Shorter fermentation (less than 72hrs), since acetic acid production peaks at 72hrs after the start of fermentation.
Proper length of conching, which varies, allows acidity to evaporate
Gentle drying after fermentation allows acetic acid to escape through the shell
Acidity (overly)
Longer fermentation(greater than 72hrs)
Cocoa grown from highly acidic soils. Soils with low phosphorous levels and higher amounts of iron and copper salts. Quick drying results in a hardening of the cacao bean shell and prevents the escape of part of the remaining acids and tannins in the bean, resulting in acidic and astringent flavors. Growers that artificially dry beans may also do it too quick.
Astringency
Germinated beans can cause this
Quick drying stops the chemical reactions started in fermentation and prevents the escape of part of the remaining tannins in the bean, resulting in astringent flavors. Growers that artificially dry beans may also do it too quick.
Bitterness
The polyphenols naturally present in cacao are bitter. However, polyphenols are usually converted in to less bitter tasting chemicals during fermentation. So a shorter fermentation (or no fermentation at all) could result in a more bitter tasting chocolate since the polyphenols have not had the time to convert into different chemicals. (Some mass market companies purposely allow short fermentation in order to save money.)
If different bean types are fermented together, over fermenting of one type and underfermenting of another results since bean types ferment at different lengths. Fermenting different bean types has implications on astringency and acidity also.
Blandness
Too much conching can dispel desirable flavors
Too much cocoa butter
Possibly the result of deodorizing cocoa butter. This involves passing steam through the butter which is under a vacuum. While removing off flavors it can also remove desirable flavors.
Burnt rubber
Use of unfermented beans
Artificial drying methods
Caramel flavor
Considered desirable, it is brought out by proper roasting, which varies by bean type.
Cardboard flavor
Packaging, sometimes plastic style wrappers contribute this.
Creaminess
Use of an emulsifier such as lecithin
Added cocoa butter
Long conching period
Earthy notes
Considered desirable, it is brought out by proper roasting, which varies by bean type.
Floral notes
Considered desirable, it is brought out by proper roasting, which varies by bean type.
Fruity flavors
An increase in acidity is strongly correlated with an increase in fruitiness
Long conching periods may increase the presence of chemicals known as “strawberry” furanone
Might be the result of acid rain
Grainy texture
Conching was not adequate (with respect to time or machinery)
Chocolate not tempered properly
Grassy odors
Beans stored under humid conditions may absorb the odor of the burlap bag they are kept in.
Ham
Smoke from drying the beans over wood fires (* regions that harvest a lot of cacao during rainy seasons or cloudy weather must use artificial drying methods to decrease moisture.)
Overfermentation may result in production of chemicals responsible for this flavor.
Heavy metals
Soil makeup and not fertilizers. Ex. Volcanic soils have higher levels of cadmium
Off flavors
Use of synthetic ingredients such as vanillan, lactose, malitol, whey powder, cocoa powder, malt extract, butter fat, emulsifiers other than lecithin
Oily, resinous flavor
Drying beans over an open fire
Smokey flavor
Wood burning to dry beans without proper ventilation often results in a smokey contamination of the beans.
Smooth texture
Long conching period
Sour, harsh or flat flavors
Using a gas fired dryer and the lack of slow sun drying (* regions that harvest a lot of cacao during rainy seasons or cloudy weather must use artificial drying methods to decrease moisture.)
Spoiled/moldy taste
Chocolate made from beans with > 3% mold (measured by a cut test). The longer the grower delays fermentation or drying, the greater the risk of mold. Cocoa free from mold or bacteria doesn't exist. The goal is to keep them to an acceptable level and then the roasting process often kills what is remaining.
Sweetness
Considered desirable if light, it is brought out by proper roasting, which varies by bean type.
Unexpected flavors
Storing strong smelling products next to or introduced to the beans either intentionally or by accident.
Blending beans from different plantations can produce unexpected flavors
Wine-like
Extra tannins in the beans
Appropriate level of acidity
