In other, less trustworthy, parts of the world, caviar is sold in jars so that the customer can see what is being bought and have a little more confidence in the product. I hope that this is not needed in the UK and is hardly relevant to an internet company like Caspian Caviar. Anyway, a visual inspection through a thick glass jar hardly helps to identify dyed Pike roe!
As is often stated, metal does change the taste of caviar. However, food grade tins are laminated, so the caviar does not touch the metal. Supporters of jars say that rust can be an issue. I have never seen it unless the tin is visibly damaged. A damaged jar could be harder to spot and who wants chards of glass in ones caviar?
All in all, we are very happy to continue supplying caviar in tins. A caviar tin is a caviar tin. A glass jar with caviar in it looks like a refugee from the cosmetics industry.