Caviar guide: Pro shares his tips on how to buy and eat sturgeon roe

(CNN)"They look like diamonds," says Alexandre Petrossian as he holds a tin of caviar under the light.

The fish eggs sparkle inside his namesake restaurant in the historic Alwyn Court Building on 58th Street and Seventh Avenue in Manhattan, one block from Central Park.
Caviar expert Alexandre Petrossian.
Petrossian -- the third generation to work in the luxury business founded by his grandfather in Paris almost 100 years ago -- is here to guide the uninitiated through the fascinating process of selecting and eating the finest caviar.
Though the delicacy of Russian royalty still ranks among the most expensive foods in the world, costing up to hundreds of dollars for a tiny bite, Petrossian is anything but pretentious.
Instead, he's unabashedly passionate when sharing his love of sturgeon roe and introducing others to it.
"It's often the case that people are afraid of trying caviar for the first time," he says. "They don't want to invest their life savings. But there are ways you can enjoy caviar without breaking the bank."

Work your way up

Top grade caviar is usually lighter in color.
Petrossian advises novices to "come with a learning attitude" and "to educate" their palates, which he compares to the journey of becoming a wine connoisseur.
"Don't buy too high a grade at first, it's not necessary," he says.
"Start with the lower grade and work your way up."
Top grade caviar is usually more mature and lighter in color. He suggests first-time buyers try tranmontanus caviar from California, which costs about $50 for one serving.
Though Caspian Sea beluga is a name usually associated with caviar, overfishing endangered wild sturgeon so importing it became illegal in 2005.
Luckily, farm-raised tranmontanus is somewhat affordable, "easy to enjoy and you'll have the total experience of delicious caviar," says Petrossian.
After trying this "Mercedes of caviar," you can proceed to "the Rolls-Royce and the Maybach."

Don't buy it till you've tried it

"Try the caviar you're going to buy, that is key," as taste can vary from tin to tin, he says.
And a buyer should always be wary, Petrossian cautions, as sometimes caviar is a "fishy business -- I mean that without being funny."
A few shady distributors purposely mislabel tins, akin to putting a Chanel tag on a knock-off purse.
Petrossian suggests always examining the CITES (Convention on International Trade in Endangered Species) number that's on better tins.
This international organization, which regulates wild game, names the actual fish the caviar came from.

Keep it cold

Once you purchase your caviar, there's about a six-week window to enjoy it.
Petrossian stresses that temperature is key.
"Put it in the deepest and coldest part of your fridge, usually where you store vegetables," he says.
"Open the tin at the last minute and then put it on crushed ice."

Hold the silver, but not the vodka

When it comes to spoons, avoid silver, says Petrossian.
Now the tricky part, how exactly do you eat caviar?
First, you'll want to "feel comfortable around these little fish eggs," says Petrossian.
So relax, this is a treat to savor.
Second, you need a spoon made out of a neutral material like wood or bone as silver reacts with the fish eggs.
Put about a half teaspoon in your mouth and "crush the little eggs with your tongue on your palate. Just mix the oil," says Petrossian.
For the purest experience, he likes to eat caviar "straight out of the tin" -- you can add toast points and creme fraiche as your taste develops.
Your first bite of caviar should dazzle, bursting in your mouth with a satisfyingly rich, perfectly salty, exotic flavor.
To dry the palate before the next delicious taste, Petrossian recommends either traditional vodka or Champagne as "the bubbles remove oils on the tongue."

It's a matter of taste, not price

Forget cost. It's all about sharing the caviar experience with someone special, says Petrossian.
Sitting in his restaurant, Petrossian tries "one of the better caviars"-- a Special Reserve Alverta that runs just over $200 per serving. He takes a bite and, even after a lifetime in the business, his eyes sparkle.
"My God, it's delicious," he says.
"The eggs are huge and firm. It's deep without being too strong. The flavor is robust. You feel it on your tongue for a long time."
Despite his reaction, Petrossian says "there is no actual best caviar."
"There is the most expensive because it's the rarest," he says.
"It can be the best to you. Or the best to you can be the cheapest. It's all a matter of taste. And all tastes are different."
What matters is that when you do find your perfect tin of caviar, you are also buying the inevitable special memories that come with it, says Petrossian.
"Whoever you share caviar with makes the experience even better," he says.
One of his favorite memories was when his son tried the delicacy for the first time -- at 18 months old.
Petrossian says the toddler's first reaction was "a little, 'what is that?'"
"Then he just had his mouth open [as if to say] 'I want more. Give me more.'"
And that seems to be the prevailing trend with caviar -- after one bite, you're hooked for life.

Petrossian Cafe & Boutique, 911 7th Ave, New York City, NY 10019-2102;