MegatopLover

Consistent with our chemist fm747's advice, I've definitely experienced the problem with caviar and sterling silver but not other metals. A sloppy party guest or two has managed to damage a sterling silver dish of mine by dropping bits of caviar on it. The tarnish is essentially permanent and almost impossible to eliminate by ordinary polishing. On the other hand, in addition to the traditional mother of pearl spoons, I have used a special caviar serving utensil that is in large part silver but on the curved part of the spoon itself gold-plated: no tarnish problem and no corruption of the eggs' taste, because they touch the gold but not the silver.

Mother of pearl utensils (or a reasonable facsimile thereof) are dirt cheap in Thailand. Maybe not 10 baht a dozen but certainly cheap at retail rates. SQ could probably pick up a bunch very cheap. Even if used on a throw-away basis, we're not looking at a great deal of cost. The spoons themselves would run no more than a couple of dollars for each flight on which they're used. Cost per seat mile is, of course, a concern, but at the rates SQ charges for F tix, they've probably got some wiggle room on the cost side.

Now let's circle back to the OP's issue. I've not flown in SQ First (yet) so I've got to ask about the metal content of the utensils: were they silver after all? SQ Economy utensils are plainly stainless steel. In Raffles, they *look* silver-plated, though I'm no expert. In First, they may well be real silver, which would create the problem the OP raised. That said, the chemical reaction happens fairly fast and might even be noticeable on the spoon immediately after use.

All this has me looking forward to my upcoming first First flight on SQ. Alas, it's SQ 001, which means no fish eggs for me, not until my return flight on SQ 002 two weeks later.