A couple months ago, after I mentioned this Rio Negro delicacy, Graham Gaspard of Black River Caviar was kind enough to send me a taste of his Ossetra Caviar from Uruguay.
After taking a closer look through tastings and interviews at various drinks (Single Malt, Armagnac) beyond wine in the past couple of months, I started wondering which of these would work better with Ossetra Caviar.
I asked for expert advice on best bets.
Let's start in Gascony where Sandra, an Armagnac evangelist suggested La Blanche which has the following characterics:
"A particular method of vinification and the selection of eau-de-vie during the distillation reveals particular fruity and floral aromas.
In order to conserve these aromas and its crystal-clear aspect, it is then kept in inert containers. During its maturation, the producer works on the eau-de-vie to lower its alcoholic degree in order to bring out its fruitiness and roundness in the mouth."
I did not taste it so I will trust Sandra's word.
For single malt and scotch, I checked with Marcia of Sip Smoke Savor who I had the pleasure to meet at Single Malt and Chuao Chocolatier tasting.
Here's Marcia's take:
"The first scotch that comes to mind for pairing with caviar is the Springbank 10 year old 100 proof. It is fresh and invigorating
, slightly briny and lightly smoky. With 2 ½ times distillation, it is very smooth for its high alcohol content and young age."

Sake not being my forte, I called Sakaya NYC for some recommendations.
Rick Smith who with his wife Hiroko Furukawa owns the shop gave us his thoughts on the topic.
"The best sake pairings for caviar are from the top classification of premium sake called Daiginjo. This means that they use highly milled rice (which makes it more refined in flavor and texture). The two that we've recommended to go with Ossetra caviar have sufficient acidity to cut through the oily character of the caviar while also possessing sweetness to balance with the salty flavor.
Wataribune "Ferry Boat" Junmai Daiginjo (Ibaraki) - Deep, luscious, and layered with big, but well-balanced fruit flavors of peach, melon, and pineapple.
Katchou Gesseki "Morning Flowers, Evening Moon" Daiginjo (Akita) - Light clean, and refined with notes of orange blossom on the nose and hints of honey and pineapple on the palate.
These are fairly expensive sake but well-worth the investment!"

To conclude, you might want to read Caviar Basics, Drops of Delight (Food Paper) by Ben Narasin which will guide you in your purchase and adds other pairing suggestions.
Sakaya NYC was featured in Sake Rewards the Adventurous Drinker by Eric Asimov (The Pour, NY Times, July 27)
(* Sake illustration is 'Wataribune' Ferry Boat)