Onion Caviar: the fun, easy appetizer recipe you need to try

Total time: 30 Min + Resting Time
Difficulty: Low
Serves: 6 people
By Cookist

Want to impress your friends with your molecular gastronomy skills? Then you should definitely make this onion caviar for your next party or event. While it might look complicated, onion caviar is actually a very easy appetizer recipe.

To make it, you soak onions in a vinegar mixture. This draws out all the oniony flavor you need for the small flavor balls. They look just like real caviar, but they’re suitable for vegetarians, full of flavor, and so much cheaper!

To make it, you’ll need red onions, balsamic vinegar, red wine, agar agar, oil, and creativity! Best of all, your friends might just think you’re the next Heston Blumenthal!


If you use dark balsamic vinegar, it will make the onion caviar darker in color and it will taste fruitier. You could also use another vinegar of your choice, like apple cider vinegar or red wine vinegar.

Most oils will work for this recipe. Try olive oil (you can re-use the oil, so don’t worry about the price tag), sunflower oil, canola oil, or even peanut oil.

Agar agar is what turns the onion liquid into a gel-like substance so that it forms little balls. It’s also vegan, so perfect for your vegan friends.

For the small balls to form, the oil must be cold (put in the fridge for 15-30 minutes), and the glass must be tall. A tall glass provides the balls with a long enough distance to travel to form perfectly.

If you find that dops aren’t forming properly, it could be because the agar agar didn’t dissolve properly in the vinegar mixture. Also make sure that the vinegar has cooled down completely, and that the oil is cold.

Serve the onion caviar on bread, or as a garnish on appetizers.

How To Store Onion Caviar

The onion caviar is best served immediately but can be stored (in a clean, airtight jar) in the fridge for up to one week.

Red onions
100 ml
Balsamic vinegar
100 ml
Red wine
60 ml
a pinch
agar agar
5 g
Cold Water

How To Make Onion Caviar

Cut an onion into thin slices, and place in a bowl.

Add water, vinegar, and wine, and let stand for 1 hour.

Strain the liquid, place it in a pot and bring to a boil.

Add the agar and mix.

Pour the liquid into a pipette.

Fill a tall glass with oil and chill. Use the pipette to slowly let out several drops forming the caviar.

Carefully pour the oil containing the droplets into a sieve set over a bowl.

Rinse with cold water.


You will need a pipette or dropper for this recipe. This will be used to drop the liquid into the oil, creating small balls of ‘onion caviar’. If you cannot find one, you could use a syringe (this will create very small drops), or a squeeze sauce bottle (this will create bigger balls).

Every dish has a story
Find out more on Cookist social networks