Yes, I am being serious!
Did you know that some wine may contain traces of food products which are on the EU list of allergens – substances which have been known to cause an adverse reaction in humans?
Some of these are:
You’re probably asking yourself the question, ‘Why?’
Part of the wine-making process is called fining. This is when something is added to wine to remove suspended particles which make it cloudy.
Casein, a protein derived from milk, is one of the substances wine-makers use to make white and rosé wine bright and clear.
Not wishing to put you off from quaffing a glass or two of Italy’s finest, a substance called isinglass, which comes from fish swim bladders, is also used to clarify wine!
Egg whites may be put into red wine to remove tannins. These occur in grape seeds, skins and different sorts of bark. The presence of tannins affects the astringency of a wine, so, with some varieties wine-makers like to remove some tannin to make the flavour mellower.
The tannin binds to the egg white and sinks to the bottom of the barrel. It’s then separated from the wine – so in reality, only a microscopic amount of the egg protein, if any, ever reaches a wine glass!
In contrast, wine-makers may wish to add tannin to their wine and this is sometimes in the form of chestnuts.
You’ll be relieved to know, there is absolutely no evidence to link wine with any allergic reaction. The amounts of potential allergens occur in such low concentrations that they are negligible.
In a recent study of Italian wines it was estimated that an adult threshold for casein (milk protein) sensitivity was 10 mg. Going by the amount of casein detected in the wine, less than 0.28 parts per million, the person would have to drink 20 litres of wine in a short period of time in order to elicit an allergic reaction. I would imagine that alcoholic poisoning would prove to be more of a risk!
In the past, wine was not considered to be a food by global health and safety advisory bodies, so was exempt from labelling to alert consumers to possible allergens.
That has all changed now.
See COMMISSION REGULATION (EU) No 579/2012 of 29 June. (I’m sure you’ll want to read every word!)
“All wine produced from the 2012 and subsequent harvests of grapes that have used eggs and milk as fining agents and where these materials are still detectable in the wine will have to declare this on the labels.
This is why you may see wine labels stating, for example, “Contains egg” or “Contains milk casein.”
Our strap-line at Campania Food and Wines is ‘In Vino Veritas’ – ‘In wine there is the truth.’ I guess we can now say – ‘In wine labelling there is the truth!’
 Restani, P., Uberti, F., Danzi, R., Ballabio, C., Pavanello, F., and Tarantino, C. 2012. Absence of allergenic residues in experimental and commercial wines fined with caseinates. Food Chemistry 134: 1438-1445.