Like any type of food, not all caviars taste and cost the same. There is a logical standard that is followed (known as grades) and caviars (both sturgeon-based and caviar substitutes) undergo a considerable amount of scrutiny to determine just how good it is. Several factors will determine where a particular caviar falls on the rating scale, and thereby determine how delicious, and expensive it will be.
The following list represents the factors that determine the rating of a particular caviar.
Egg Colour: The colour of the egg is a true determinant to the overall quality of a particular caviar. The colour of the eggs are generally dependent upon the age (maturity) of the fish, and as a result the colour of the eggs will vary with age as well. For example, in Osetra caviars, as the sturgeon ages (matures) the colour of the eggs will lessen from gray and turn golden brown in colour.
Egg Maturity: Not unlike fine cheeses and wine, caviar’s taste drastically improves when the eggs are processed at a certain time in the fish’s life. For example, the best tasting (high-quality) Sevruga caviars are those that come from roe when the fish (Stellate Sturgeons) are around 20-years of age.
Egg Clarity: Like a good diamond, the egg’s shiny outer coating determines the freshness of the eggs. Eggs should be shiny (glistening) and slightly transparent to reflect freshness, as dull, oily or murky looking eggs tend to be less fresh or were not stored properly (not preserved as well).
Egg Size: Depending on the type of fish from which the eggs were extracted, caviars in turn, will range in size. Beluga caviar (the largest eggs) are the size of an average pea. In this case, only eggs that are pea-sized (based on the accepted size range for that particular fish) from the Beluga Sturgeon will be deemed mature enough for harvesting to make caviar.
Egg Consistency: Like a good strand of pearls, the overall consistency of the caviar’s appearance should be uniform throughout. In other words the characteristics of each egg should be similar (almost identical) in factors such as size, colour, etc. to all other eggs in the caviar group.
Eggshell Resiliency: The requirement in this regard is a fine line. Firstly the egg must be strong and resilient enough to withstand the rigors of the caviar-making process, yet be soft enough to dissolve on the palate when eaten. All good-quality caviar eggs possess a strong appearance, and the resilience to endure the processing and yet still have a tender element as well.
Egg-grain Separation: The initial sieving/filtrationprocess is very delicate, as it removes the attaching membranes that join the eggs together. The difficulty or ease of separation determines the resiliency of the eggs during processing. Eggs that do not make it through this early stage, will undoubtedly not be able to withstand further processing.
Fragrance: Ideally, the freshest caviar should possess a “fresh ocean scent.” This in turn, reflects the overall freshness of the eggs themselves, which makes sense, fresh fish=fresh scent. Naturally the fragrance is determinate of how fresh the eggs were at time of processing, and the overall scent could (fresh or fishy) could be an indication of salting, brining, or a storage issue as well.
Grade: There are four basic grades in Caviar as follows: Beluga, Osetra, Sevruga, and Pressed (as described in a previous article).