Hi Jim-this is Danielle the resident caviar expert. What kind of caviar are we talking about? Sturgeon, flying fish row, salmon, trout, whitefish....There is definitely a difference in how these products should be handled. Salmon, trout and whitefish don't generally have any salt or preservative added to them so they can be frozen easily. The containers should be plastic not metal. There is a dissolving of the eggs membrane that would naturally occur (don't know the exact scientific name) that would be excelerated if frozen in metal. They can be frozen for quite some time but the quality in salmon, whitefish and trout does seem to deteriorate after 30 days or so. Tobiko or flying fish roe has a thick membrane and a very small berry so these freeze almost forever! Note: They shouldn't necessarily be re-frozen after they have been thawed.
As far as sturgeon goes there are some domestic products that freeze alright. Paddlefish and american sturgeon seem to hold up fairly well(in plastic containers). They really don't contain as much salt as the imports. The imports usually come in tins or glass jars and these should never be frozen. The quality really is noticably different. If you are looking for a product that lasts longer you can purchase a pasteurized product that will have increased shelf life. There is a difference in taste and texture between pasteurized and un- pasteurized.
The worst things for sturgeon caviar are light and air. I recommend purchasing product in metal tins. This way if you use a little and immediatley put it away you could probably get away with 5 days on it.
Did I miss anything? Let me know.  | 
