Julie Harrison - Wine Additives

Just what goes into wine apart from grape juice and yeast? There are a number of different additives allowed in wine some of which are quite unexpected.

Sulphite is probably the best known wine additive and you will find it listed on the label as :

• Contains sulphites/sulfites or
• Contains preservative E220.

The term refers to the presence of Sulphur dioxide (SO2) in the wine. Sulphur dioxide stabilises and keeps the wine “fresh” by protecting it from microbial contamination and helping prevent oxidation. Sulphur dioxide is actually a by-product of fermentation so even if none is added to the wine it will still be present at some level. So is it bad for you? It is estimated that around 5% of the population is allergic or sensitive to Sulphur dioxide and adverse reactions are usually associated with people who suffer from severe asthma. Wines may contain up to 300ppm (parts per million), with many containing a lot less. As a guide red wines will contain less sulphites than white wines as the tannins in the red help in stabilisation. One of our French suppliers has recently produced a red wine with no added sulphites which we hope to bring in when we get our next shipment. It is a very intensely coloured wine which helps protect the wine from oxidation. Cask wines and sweet wines will usually contain higher levels of sulphites. Other food products actually contain much higher levels of Sulphur Dioxide than wine. Dried fruit contains up to 2000ppm of SO2, so if you do have an allergy to sulphites you are likely experience problems with dried apricots. Sulphites get bad press and often receive the blame for “red wine headaches” but tannins, histamines or alcohol are the more likely culprits. Do remember that some wines contain a lot more alcohol than others so it pays to read the label. Australian reds can sometimes contain a headache inducing 15% alcohol level, which packs a punch even with just one or two glasses.

The process of “fining” is where some interesting additions can occur. Fining removes astringency and/or bitterness in a wine as well as small particles that make the wine cloudy. Various compounds are used depending on what you want to remove. The idea is that the fining agent binds to what you want to get rid of and the combined larger molecule falls out of the wine sinking to the bottom of the storage vessel. The clear wine is then “racked off”. Common fining agents are egg whites, Isinglass (made from the swim bladders of fish!) milk products such as casein or skim milk, carbon, gelatine and bentonite (a fine clay product). Copper in the form of Copper Sulphate may also be added to wine to reduce smelly Sulphur aromas. Of course the amount of these products in the final product is tiny. Some wineries avoid fining altogether as sometimes good bits get taken away by the fining agent, stripping the wine of flavour and/or colour.   Have a look at the label next time you buy wine as many producers will report what has been used for the fining process.  Examples of label descriptions are:

• May contain traces of milk
• Contains egg product
• Fined with milk product
• Fined with milk and fish products.

Wineries that don’t fine the wine will often mention this on the label.

There are other wine additives such as ascorbic acid (vitamin C) which works as an antioxidant and B vitamins to keep the yeast cells happy. Depending on where the wine is from sugar or concentrated grape juice may be permitted to raise the sugar level in grape juice (chaptalisation). Some countries permit the addition of acid (usually Tartaric or Malic Acid) or de-acidifiers (Calcium Carbonate) to balance the acidity of a wine. Generally speaking warm countries are usually permitted to add acid as the heat reduces the acid levels in grapes and cooler countries are allowed to add sugar as sometimes the weather is not good enough to ripen the grapes fully.

Wine is mostly just wine but if you are vegan or suffer from asthma then some wines may not be suitable for you and it will pay to read the label.