What Caviar Tastes Like? A Primer
Introduction: some key pointers and background facts
The ultimate quality indicator of caviar is obviously the taste of the caviar itself, in addition to its nutritional value. Tasting samples to check caviar product quality is routinely done every single individual time a caviar product is traded, while it is in storage and before serving.
Tasting should be done in a professional manner, taking samples on their own without accompaniments after first cleansing the palate. Caspian Monarque has written this guide as practical guide designed to inform everyone from the occasional caviar consumer right down through to the caviar connoisseur and caviar master.
The guide is unfortunately but necessarily lengthy given its objective of answering the question on what caviar tastes like. In doing so, we do not cover anything but taste, so topics such as egg size, lucidity and others are not discussed. They are discussed in our other guides.
Note: In conducting any caviar tasting, it is first essential to determine if artificial or natural waters were used in growing the sturgeon that your caviar came from. Producing caviar is neither an easy, mechanical, or short-term process. One beluga sturgeon can take up to 25 years to produce caviar, and so the sturgeon that swim and live in a farm that uses the high quality natural waters compatible with the genetic make-up of the sturgeon will always be of superior grade and quality.
It is for this reason that Caspian Sea waters have always produced the most expensive and high quality caviar. The Caspian Sea has been the native habitat of sturgeon fish for millions of years and thus is an excellent and sustainable ecosystem that ensures quality. New caviar farms in Europe and China suffer from the problem that their sturgeons have –literally–been living in artificial (and sometimes hormone-laden) waters for their entire life time and thus produce low quality, tasteless caviar. It is somewhat akin to expect a human to breath on the moon or a Kangaroo to be raised in the frozen forests of Siberia.
Room Temperature and Caviar Tasting
Tasting for product grading purposes should be done with the product at room temperature of about 18°C (65°F), although when eating caviar the best serving temperature is about 10 to 12°C (50 to 55°F). In cold caviar the flavor is less pronounced. Less desirable aftertastes, sometimes described as muddy or grassy (particularly found in artificial European caviar farms), will be reduced; so will early signs of rancidity, characterized by a sharp flavor. The warmer temperature suggested for tasting will highlight defects of flavor.
Warning: Do not taste samples of caviar for product grading purposes from the top layer of a package, as this is most likely to show signs of deterioration and will not be representative of the container. Take samples about 2.5 centimeters or so beneath the surface. Use utensils that do not impart flavors to the caviar. Horn, mother-of-pearl and wood are traditional materials for caviar tasting or serving implements. The best time to check the aroma of a caviar shipment is immediately the containers are opened. Any accumulated odors will be immediately apparent. Since the top layers may be dry, samplers should also smell eggs taken from an inch or so below the surface.
What Does It Taste Like?
The overwhelming impression from caviar is that it tastes salty. Modern tastes prefer much less salt than was considered palatable in past centuries. High levels of salt were once necessary to preserve foods from spoilage. Refrigeration and freezing, together with modern food processing and handling techniques, have made high salt levels unnecessary in many products. The trend is no doubt helped along by the understanding that too much salt can contribute to high blood pressure and heart disease. However, it would be a very rich consumer who could afford to eat enough caviar to make the slightest difference to his blood pressure.
Caviar producers are now frequently faced with market demand for caviar with salinity as low as 2 percent. There are important considerations in this. Firstly, excessively low salinities may result in significant flavor reduction. The salting process converts the raw (uncooked) fish product to the familiar caviar product, changing the texture and creating a new, specific, natural flavor which is recognizable as caviar. If there is insufficient salt, or the curing process is not complete, our palate will judge the product as “raw.” Secondly, safe handling of low salted products requires strict adherence to storage temperature requirements and frequent checks of the pH level of the product. Drastically shortened shelf is often the result of low salinity.
Salt cures food through complex chemical changes that are not fully understood. While fish eggs cure very quickly compared with fish flesh, salt still needs time to complete the process. Salmon eggs, for example, are held after salting for several hours at room temperature before they are completely cured. During this time, they may be vacuum packed, because the curing process continues so long as the temperature is sufficiently high. If the caviar is frozen immediately after salting and rapid draining, the curing process is slowed or stopped and the product will taste raw. It is also possible to leave caviar to cure for too long, resulting in products which are spoiled because they have been held at temperatures that are too high.
What are good taste and viscosity?
The interior viscosity of the eggs is important to the “mouth-feel” of the caviar. In extreme cases the viscosity has a “mouth-feel” of watery to chewy. The best caviars feel like a pleasantly viscous liquid.
Exterior viscosity is the stickiness of the egg. It should roll down a gently sloping glass surface. Eggs in glass jars should roll if the jar is slowly shaken and rotated. It is difficult to judge exterior viscosity by tasting.
However, good taste of any particular type of caviar is a matter of perception or opinion of the consumer on the issue of what is actually ‘good’. The answer depends on ethnic traditions as well is on the promotional efforts of repackers and writers who a advertise certain quality properties which they consider to be desirable Sometimes, of course, these properties are promoted only to increase business.
An example is the “popping” texture of lumpfish roe. It is a perception of good quality which was developed and promoted as a justification of the two-step processing technology, when eggs are first heavily salted and then desalted before final packing. Much of the original flavor of the egg interior is lost as a result and what is left is an engineered food. The ‘popping’ texture of lumpfish eggs is very much appreciated by Japanese consumers. Note that beluga, osetra and sevrugas, the very best sturgeon caviars, never pop.
|Sturgeon Caviar Grading|
|Quality Index||Evaluation Method||Highest Grade||Grade No.1||Grade No.2||Pasteurized²|
|Caviar origin & fish specie||Natural waters of Caspian Sea, CITES Label’ Quality certificates, Time-termperature history||Beluga, Osetra & Sevruga farmed using natural Caspian Sea Waters. Iran and Russia are the only two producers doing so.||Beluga, Osetra & Sevruga all other sturgeon species farmed using natural Caspian Sea Waters. Iran and Russia are the only two producers doing so.||Pasteurization is often not mentioned on the label. Species not intermixed|
|Species not intermixed||Species may be intermixed|
|Color||Visual, under standardized light condition||Homogeneous color. Beluga: light gray. Oscietre: slight yellowish or brownish shades in a basic gray-black hue. Beluga-white-gray and Oscietre- goldish shades are rarities||Homogeneous color. Light gray,dark gray, black, yellowish, brownish, greenish||Any color. Color mixtures acceptable||Any color. Slight color mixtures acceptable. Color may be paler than non-pasteurized
|Appearance||Visual, over a candling table||Eggs round or slightly elongated, firm, elastic, easily separated, no broken eggs or residual tissue; reasonable moist and rotating inside a jar at room temperature||Eggs round or elongated but slightly weak; some presence of residual tissue; moist or dry & hardly rotating inside a jar at room temperature||Eggs weak and stick together in lumps; when separated eggs may burst; excessive juices released on container bottom or excessive dryness. Considerable number of burst eggs and membranes. Over-dried eggs||Eggs firmer than non pasteurized eggs, easy to separate; presence of lumps and some juice acceptable|
Sturgeon and salmon roe are not very susceptible to efforts to redefine good flavor and texture because the perception of what constitutes good taste in these products is well established, see the tables below.
|Quality Index||Evaluation Method||Highest Grade³||Grade No.1||Grade No.2||Pasteurized²|
|Egg Size³||Line up eggs over a 10 cm ruler and measure||All eggs of one size, either large or medium||Eggs of any single size||Eggs size and mixture and acceptable||Eggs of any single size
|Odor||Organoleptic, at room temperature||Typical for sturgeon, sweet & fresh; off-odors not acceptable
|Weak typical sturgeon odor, no off-doors acceptable||Slight, sharp, sour, yeasty, stable off-odor acceptable||Typical for pasteurized sturgeon. Phenol odor|
|Offensive odors not acceptable|
|Taste & Consistency||Organoleptic multiple tasting of small portions at chilled temperature||Typical for sturgeon yolky, delicate, grassy acceptable, rich and lasting. Egg membranes melt leaving a pleasant viscous liquid impression
|Typical for sturgeon some loss of yolkiness& richness; grassy but not muddy or other non-offensive after-taste acceptable. Individual egg membranes are slightly recognizable.||Some sharpness; grassy or muddy after-taste acceptable. Slight bitter or sharp & sour aftertaste acceptable. Weak sturgeon flavour, not offensive, interfering flavours. Over-dried, recognizable dryness and total loss of the membrane melting phenomenon||Typical for pasteurized caviar. Mild, modified yolky a pleasant flavour; egg membrane is tougher than for non-pasteurized caviar, slight chewiness acceptable
|Salinity⁴ % by weight||Any instrumental method||2.5 to 3.5||3.3 to 4.5||3.3 to 5.0||2.5 to 4.0|
|Notes for the table above|
|1The generic term ‘sturgeon caviar’ is used for all sturgeon fish species. The word ‘malosol’ means in Russian ‘low salted”. Low salinity is usually synonymous with high quality but the word is often misused and in fact is only a marketing gimmick. The word ‘fresh’ should mean non-pasteurized.|
|2 In principle, pasteurized caviar can be made from all listed grades, if the roe is fresh. Pasteurized caviars are not graded further and constitute a separate grade.|
|3 Elongated sturgeon eggs are lined up along the larger axis. Large eggs are 3 mm and over, medium 2.5 to 3 mm and small eggs less than 2.5 mm. Salmon eggs: large eggs over 4 mm, medium 3 to 4 mm, small eggs less than 3 mm.|
|4 According to Iranian standards, caviars with saltiness less than 2.0% are processed only on special orders. Low salted highest grade non pasteurized caviar is processed only on special orders.
12 Warning Signs that your Caviar’s Taste is of Poor Quality
- Is it pasteurized?
Labels do not always indicate whether a package of caviar was pasteurized, although sometimes the word “fresh” will be used as an indication that pasteurization was not performed (in the USA or UK, use of the term ‘fresh’ would be illegal on a pasteurized product). The best indication that caviar has been pasteurized is the slightly increased viscosity of the interior egg liquid.
- Some of the defects and signs of deterioration discussed below are common to all caviar, some are typical only for certain caviar types. A review of these defects and possible causes of their appearance may help the consumer to judge quality visually and by taste. Defects may appear during processing or in storage or may be due to the combined effects of both processing and storage.
- Sharpness and odor. One of the most common defects for both sturgeon and salmon roe is sharpness in taste with a slightly detectable sour aftertaste. This condition eventually develops into unacceptable and offensive sourness and sharpness. It is often accompanied by a fishy smell and taste, depending on the specific properties of the egg fat. Fishiness is less pronounced in sturgeon and most of the ordinary fish caviars than in salmon roe. In sturgeons, this is because of the chemical composition of the fat. In most of the ordinary fish caviars it is due to the comparatively low fat content.
The sharpness and sourness is mainly caused by microbiological and enzymatic spoilage. In the early stages it shows as a deterioration in taste; later it is followed by an offensive smell and loss of elasticity of the egg membranes. As decomposition proceeds, egg shape collapses and a sticky slimy juice appears between the eggs and on the product surface. The slime then develops into visible mold and yeast colonies which may be found on the product surface and inside surfaces of the package. Salmon roes are more susceptible to this microbiological spoilage than sturgeon caviar. In extreme cases, egg membranes rupture, followed by a massive release of juice and strong sulphurous, ammoniac and methylaminic smells. As it decomposes, salmon roe color darkens to brownish tones and broken egg membranes appear in abundance. Changes in the color of sturgeon caviar are hardly noticeable
Bitter aftertaste in caviar has many possible causes. Firstly, bitterness is noticeable in over-salted products which is nearly always the case with farmed European caviar or when poor quality salts, which contain excessive magnesium and calcium impurities, are used. Some preservatives, like urotropine, may cause a slightly bitter or tangy aftertaste. Sockeye and coho eggs have a slightly bitter natural aftertaste, which is caused by some unstable fatty acids specific to these species. This feature also substantially shortens sockeye and coho caviar shelf-life. Finally, bitterness may be the result of fat oxidation and hydrolysis, sometimes called rancidity. Sturgeon caviar is somewhat less susceptible to this kind of deterioration because the fat droplet is concentrated in the middle of the egg whereas in salmon eggs the fat droplets are distributed throughout the yolk.
Bitterness caused by fat oxidation and hydrolysis is easy to distinguish from bitterness caused by poor quality or excessive salt. If the bitterness is caused by oxidation it has a tickling effect in the throat and is long lasting. If the problem has other causes, the bitterness is short lived.
- Excessive chewiness and membrane aftertaste in caviar processed from over-mature salmon roe is impossible to recondition. The same applies to over-pasteurized sturgeon and salmon eggs, where the viscous inner yolk hardens and the caviar tastes rubbery or chewy. Attempts have been made to get rid of the rubbery texture in over-pasteurized sturgeon caviar by freezing and subsequent slow defrosting. Improvements were hardly noticeable.
- Other off tastes. Caviar may have mild to strong off-tastes which are specific to the fish habitat or feeding patterns. The best known are the grassy or muddy off-tastes of sturgeon caviar, particularly of Caspian Osetra. Beluga and sevruga caviar do not show noticeable off-tastes. In the trade, many argue that these off-tastes, when present mildly, contribute to a distinctive flavor bouquet, which described as ‘nutty’ and should be appreciated.
These off-tastes appear when sturgeons are caught in shallow, artificial waters in caviar farms overgrown with weeds, or on a silt bottom. The off-taste may change during the season and depends on the area of harvest. If the off-taste becomes strong, caviar is downgraded. The only way to reduce or remove such off-tastes and accompanying off-odors is to keep the fish alive in flowing water for 15 to 20 days before harvesting the roe. Successful attempts have been made to mask off-tastes in caviar by artificial flavoring.
Caviar off-tastes may be caused by inadequate processing or fishing practices such as exposing caviar, after salting and before packing, to air polluted with gasoline or smoke, or to poor sanitation practices.
- Metallic off-tastes may result from the use of tins which are not appropriately protected with lacquer. If the product is stored for a long time in these tins, it can absorb taints from the soldered seam and even from the tin material itself.
When under-salted salmon roe (salt content of 1.5 to 2.5 percent) is subjected to temperature abuse, a slight sulphurous smell (similar to rotten eggs) may sometimes appear very quickly, before other spoilage indications. If noticed in the very early stages, within days after packing, salmon roe can be briefly rinsed in brine and re-salted with fine salt. The reconditioned caviar should be consumed within days. The product must be sold as lower grade caviar and its safety should be checked according to regulations. An expert evaluation and certification is mandatory in Iran, for example.
- A defect which applies only to sturgeon caviar appears in the form of small, white, non-soluble and odorless crystals 0.1 to 1 mm in size. They appear in sturgeon caviar if it is pasteurized or after prolonged storage of unpasteurized, bulk product. The crystals are not attached to the eggs. They look like farina or tiny snowflakes and are distributed throughout the caviar mass between the eggs. The larger ones have an irregular shape with protruding spiny edges. They develop faster at higher temperatures. The crystals form as a result of protein hydrolysis and consist mainly of tyrosine and other ammo acids. High salt content of caviar does not prevent but actually enhances this phenomenon.
Usually, but not always, the appearance of the crystals is a sign that the product is not usable because of general spoilage. However, the crystals themselves are not harmful. It is impossible get rid of them, and the caviar has to discarded. If pasteurized sturgeon caviar is to be stored for a very long time, it should be frozen to prevent the formation of these crystals.
- Color variations between different lots of caviar are not considered defects, unless they are related to general spoilage, such as the darkening which occurs in aging salmon and whitefish caviar. In sturgeon caviar, color changes during storage are hardly noticeable. Caviar colors are not considered to be a reason to claim a defect. For sturgeon caviar the diverse shades may only be used to downgrade the product because of the traditional preferences of the consumer. The small black Caspian Sevruga caviars may be superior in taste to the larger Osetra eggs but the consumer may prefer Osetra because of the greyish color.
Salmon roe color deviations depend on fish species and area of catch. They may also indicate temperature abuse during storage. Caviar color can be evaluated visually or measured instrumentally. Any instrumental measurement method which provides for reliable repetitive figures and is sensitive to minor changes in caviar color shades is acceptable. Instrumental color measurements have confirmed changes of the light orange-reddish tones towards dark-reddish when eggs are held for a long time on ice before processing. Be careful not to confuse these negative changes with the naturally darker red colors of coho and sockeye caviar.
- Dehydration. A typical defect is the drying up of those layers of caviar which are exposed to air or to absorbent packaging materials, such as the upper layer in non-vacuum containers, or layers adjacent to cotton linings in wooden boxes. This defect is usually remedied by either discarding the affected layer if the drying is severe, or by turning the container upside down for 5 to 7 days to redistribute the moisture. Some repackers may mix the dried layer into the container, again to redistribute the moisture more evenly. If the dried up layers show signs of oxidation or bacteriological spoilage, turning or mixing of containers may damage the whole lot.
- Burst egg membranes constitute a whitish, flat, egg “skin” which has released its interior yolk. They appear as a result of using immature or stale roe, from product spoilage during storage, because of mechanical damage during packing or transportation, from improper screening, rushed defrosting or because the product has been frozen (and thawed) twice. Burst membranes inflict another visible defect by creating excessive viscous juice. Burst membranes appear mainly in salmon roe. Rushed defrosting of frozen salmon roe with initially weak membranes may result in every egg bursting. Thawing slowly at only 2°C per day is recommended. In fact, even No. 1 Iranian grade caviar may contain some burst eggs. Note that when excessive watery juice is not accompanied by burst membranes, this indicates inadequate draining after salting.
Burst eggs can be picked out using tweezers. These defects can be seen more easily if the eggs are placed on a candling table (a glass surface evenly illuminated from below). Burst eggs should not be confused with partially ruptured and collapsed eggs. It is quite common for some salmon eggs to have broken outer membranes, where the viscous internal yolk is not released. These collapsed eggs may constitute 10 percent of the eggs in good quality caviar, more than 25 percent in poorer grades. They are not a quality defect unless excessive. To check for burst or collapsed membranes, drop a sample into fresh water. After several minutes, the burst membranes can be seen.
- Impurities are noticeable in the form of excessive residuals of connective tissue or lumps of unscreened eggs still held together by the connective tissue. they appear mainly in salmon roe. Before such caviar is packed processors may be able to remedy this defect by running the caviar through the screening device for a second time. When the caviar has been stored for a while this may be impossible because the eggs are not as easily separated. There should be no obvious impurities or foreign material in caviar.
An Extra Note: How salty should it be? Health Warnings
The major public health risk from vacuum packed caviar is the possible presence of the anaerobic bacterium Clostridium botulinum. This organism grows without oxygen and creates toxins which can cause potentially deadly botulism poisoning in humans. Occurrences of botulism from any source are fortunately and remarkably very rare in North America, but health officials and the food industry are constantly aware of the risk and watchful for conditions which might permit the growth of botulinus spores. Most recorded outbreaks have been traced to foods canned at home, or to traditional sun-dried and fermented foods such as sun-dried whole salmon ovaries. There are no proven cases of botulism poisoning from commercially produced caviar products.
The organism grows best in an environment which is low in acid, lacks oxygen and is, in general, warmer than about 3°C (38°F). The Health Protection Branch of Health and Welfare Canada carried out experiments in 2002 to test the effect of salt and pH levels on botulinus toxins in caviar products. The results of these and other experiments are summarized in table 6.4 which shows levels of salinity required to assure the safety of caviar products at different pH and moisture content levels.
There is no sensory warning of the presence of botulism. There is no off-odor, for example, because most yeasts and bacteria causing spoilage are aerobic, requiring oxygen, so do not multiply under vacuum conditions like botulinus. Vacuum packaging of fresh, low-acid seafoods is regarded with suspicion by many health authorities because of the potential risk of botulism. Vacuum packaging is safe for the same products if they are frozen because freezer temperatures are too low for the organism to grow.
Note that the chances of caviar containing botulism are extremely small. The raw material itself, the fish egg, is essentially sterile. Hygienic handling and good plant sanitation should effectively preclude this risk altogether.