It may sound like an odd question; an egg in wine? Winemakers use many different products to fix flaws and flavors. But it usually difficult to know which ones have gone into your glass.
There’s no law requiring bottles to be labeled with
these ingredients, and it seems that most winemakers don't want to disclose that information.
Among the things used in wine making are animal products including isinglass which is derived from fish bladders, casein which comes from milk protein, gelatin and egg whites. So, in fact, there may have been egg in your wine before it was bottled.
Egg whites are just one of the products used in the process called 'fining' of red wines. Adding a solution of egg whites and water to the wine as it ages initiates a process that removes solid particles by binding to loose particles in the wine and causing them to settle out so that sediment can be easily removed before the wine is bottled. The fining agents are typically undetectable in the final product, with only trace amounts remaining.
The result is a stable, clear and pleasant-looking glass of wine instead of something that would otherwise be cloudy-looking.
Here's to raising a clean and clear glass of red wine. Cheers!