The Wine Blokes

Have you ever read the back label of a wine and noticed the disclaimer, “traces of egg may remain” or “Preservative 220 added”?

By law in most countries, wine producers are obliged to adhere by these regulations and note them on the label. But what exactly does it mean? Many people have asked me why a winemaker would put egg in his or her wine.

First of all the entire egg is not added, only the egg white. There are chemical properties of egg white that make it a very effective fining agent that can remove harsh or bitter phenolic compounds from wine.  Traditonally it is used in red wine, to improve the mouthfeel and softness on the palate.

In days gone by, winemakers would literally collect eggs and physically remove the yoke from the egg white, and add a nominal amount.  I can actuallly remember watching a winemaker on a university excursion cracking eggs on a barrel and adding the egg white through the bung hole. Of course it was just for the theatre, but it’s how it was done in the past. These days winemakers can purchase bulk egg white. 

Even though disclaimers are added on labels, it is very unlikely any traces will remain in the wine.  Essentially the egg white binds with the phenolic compounds in the wine, which then settle to the bottom of the storage vessel. The wine can then be racked off the top, leaving the egg white behind.  The wine will more than likely be filtered prior to bottling, thus further removing any unwanted residue.

The preservative 220 is Sulphur Dioxide, the extremely common additive used in winemaking to prevent oxidation and bacterial spoilage. 

So generally there is nothing magic or mythical about additive to wine, and generally nothing to be concerned about, health wise or culturally.