THE ‘HANGOVER’ AND SULPHITES IN WINE!
I still get asked for an opinion on what in wine is responsible for the morning after headache. This remains a debatable subject and depending on what you know, what you have experienced and even where in the market you sit…the answer remains evasive!
The information below is my own interpretation across a myriad feast of published material, as well as many years working in the local wine industry and whilst relaxing over a glass or two at the end of the day!
Okay let’s get started…!
The term sulphites are an inclusive term for sulphur dioxide (SO2), a preservative that’s widely used in winemaking (and most food industries) for its antioxidant and antibacterial properties. SO2 plays an important role in preventing oxidisation and maintaining a wine’s freshness.
All wines contain sulphur dioxide (SO2) in various forms, collectively known as sulphites. And there is always sulphur in wine, even in wines that claim to be sulphur-free. This is because the yeast that convert the sugar from grapes into alcohol produce small amounts of sulphur as a by-product.
In completely un-sulphured wine, it is present at concentrations of up to 10 milligrams per litre, and all commercially made wines contain from ten to twenty times that amount!
So why does all this matter, well there are three reasons you might not want sulphur dioxide added to your wine.
Firstly, sulphur dioxide has a rather unpleasant smell, like that of a struck match and which is detectable at very low concentrations, and so a sensory indulgence you could do without!
Secondly, sulphur dioxide can cause potentially fatal allergic reactions and has been linked with numerous other health problems, including the dreaded hangover!
And lastly, adding sulphur dioxide breaks the principle of naturalness in wine!
So how much is too much, well this depends on the type of wine, the sensitivity of the taster, and the ratio between free and bound sulphur dioxide in the wine.
Only a proportion of the SO2 added to a wine will be effective as an antioxidant. The rest will combine with other elements in the wine and cease to be useful. Typically, half of the amount of sulphur dioxide will be free and the other half bound!
Okay let’s look at sulphur levels in different types of wines.
RED WINES do not need any added sulphur dioxide because they naturally contain antioxidants, acquired from their skins and stems during fermentation. Conventional winemakers add some anyway. Red wine also contains tannin, which is a stabilizing agent, and almost all red wines go through malolactic fermentation. Therefore, less sulphur dioxide is needed to protect the wine during winemaking and maturation.
BOTTLED FERMENTED SPARKLING WINE or traditional method sparkling wines cannot have high levels of sulphites due to the requirement of undertaking a secondary fermentation in bottle. Sulphites would prevent this from occurring if too high, so these wines are generally low in sulphites (a small addition may be made during the disgorging process). Like all carbonated beverages, Champagne (Sparkling wine) contains tiny little pockets of carbon dioxide. The satisfying fizz in soft drinks and sparkling wine is created when carbon dioxide gas under pressure is dissolved in a liquid.
Champagne feels like it goes right to your brain because it does. The carbon dioxide gas bubbles in Champagne help your body to absorb the alcohol faster. The bubbles increase the pressure in your stomach, which forces alcohol out through your stomach’s lining and into your bloodstream for faster absorption. In your bloodstream, the carbon dioxide competes with oxygen, which is why champagne makes you feel dizzy. You’ll also get drunk faster – and your hangover will be worse!
WHITE WINES & ROSE’S do not contain natural antioxidants because they are not left in contact with their skins after crushing. For this reason, they are more prone to oxidation and tend to be given larger doses of sulphur dioxide.
SWEET WINES get the biggest doses because sugar combines with and binds a high proportion of any SO2 added. To get the same level of free sulphur dioxide, the total concentration must be higher than for dry wines.
COOLER CLIMATE WINES have a lower pH which is a measure of the acidity, and so in theory should need less sulphites to achieve the same level of protection as wines from other regions that have higher pHs.
WINES FROM HIGH QUALITY PRODUCERS usually means that fruit arrives at the winery from the vineyard in excellent condition needs less or no intervention, i.e. sulphur additions. Good producers also understand the science of wine and know exactly how much sulphites a given wine needs for the type of wine it is.
Sensitivity to sulphites ?
So, lets now look at sensitivity to sulphites. Most people can detect sulphur dioxide in water at around 11 mg/l. In wine, the presence of alcohol and acids means that it is less obvious.
For an experienced taster, accustomed to natural wine, sulphur dioxide becomes unpleasant at concentrations of around 20-30 mg/l, depending on the style of wine and the ratio of free to bound sulphur.
For most people the threshold is much higher, but most people have never tasted an un-sulphured wine. They may well be able to taste the sulphur but are used to the taste!
How do you tell how much SO2 a wine contains ?
Under Australian law, any wine containing more than 10mg/l of sulphur dioxide must be labelled as containing sulphites.
This is not much help. Firstly, because it includes practically all wines. Secondly, because there is no way of knowing whether the wine in question really contains 11mg/l or 200mg/l.
Organic and bio dynamic organisations often impose their own restrictions on the wine that carries their labels. A good natural wine, even one with a tiny addition of sulphur at bottling, will have levels less than half those imposed by the strictest organic organisations.
Wine labels here in Australia are governed by the Wine Australia Act 2013 and accompanying Regulations, the Food Standards Code, the National Measurement Act, and the Competition on and Consumer Act 2010.
It is vitally important that labeling guidelines are adhered to. Not all winemaking techniques used in Australia are accepted internationally and wine labelled in accordance with Australian law doesn't necessarily comply with labeling laws in export markets.
The minimum amount of information required for the label on every bottle of wine sold in Australia is the producer’s name and address, the alcohol level, the number of standard drinks the bottle contains, the statement ‘Contains sulphites’ (unless no SO2 has been added at any time prior to the wine being bottled) and either ‘Wine of Australia’ or ‘Product of Australia’.
Additionally, there must be a declaration if any of a number of prescribed allergenic substances have been used during the making of the wine. The relevant substances are milk and casein, egg whites, nuts and isinglass. The legal requirement is that the statement must say either that the substance is in the wine or that it has been used in its manufacture.
So, what are the health implications?
The World Health Organisation recommends a maximum daily intake of 0.7mg of sulphur dioxide per kilogram of body weight.
For a man of average weight this is less than a third of a bottle of a white wine with a concentration of 200 mg/l (the EU limit for dry white wine is 210mg/l).
Regular consumption of conventional wines means regularly exceeding the RDA of sulphur dioxide by a large margin. Though it needs to be pointed out that wine is not the only product with high levels of SO2.
More specifically, sulphur dioxide can cause allergic reactions in some people. It is dangerous for asthmatics even at very low levels.
There is an opinion that sulphur dioxide contributes significantly to hangovers and therefore heavy drinkers who also have to get up in the morning, would be advised to stick to natural wine.
Though it should be said that medical research is not definitive on the relationship between sulphites and headaches. And there are many other compounds in wine such as histamines and tannins that are more likely connected to the headache effect (not to mention alcohol!).
Another surprising fact is that wine contains about ten times less sulphites than most dried fruits, which can have levels up to 1000 ppm. So, if you regularly eat dried fruit and do not have any adverse reaction you are probably not allergic to sulphites.
In practice it is likely that most wine makers work with sulphite levels that are generally well below the maximum permitted limits.
As indicated earlier, leaving out sulphites is easier with red wines, because the tannin acts as a natural antioxidant. It also helps if natural wines are sold locally and not shipped. This local aspect of “natural” wines is part of what makes them so interesting; they’re often best discovered close to their place of origin. This is far more common in the old country than the new and with a home-grown market on their doorstep!
If sulphites aren't the villain, then what is...?
Sulphites cannot provoke an immune response, which is required for something to be an allergy, and moreover, the levels present in most wines are not even worth discussing from a health perspective…hmmm now that is interesting?
It is possible that you are sensitive to sulphites (believed to be approximately 1% of the population), and to some people this is a serious condition. However, this manifests itself in ways more similar to asthma with symptoms such as wheezing, chest tightness and coughing. It is more than likely that you would have discovered your sensitivity to sulphites well before wine due to the comparatively small amounts in wine compared to other regular food and drinks.
So, what is it in wine that can give you those big headaches, congestion, and feeling like you have been hit by a truck? Well, the answer could be biogenic amines. These substances do provoke immune responses.
A winemaking process called malolactic fermentation is a common source of amines that all red wines go through as do many Chardonnays and sparkling wines. Aromatic whites such as Riesling, Sauvignon Blanc and Pinot Gris are unlikely to have undertaken this process.
So straight away you can see the problem here. People are avoiding white wines, which they rightly believe have more sulphites to avoid getting a headache. However, the red wines they are changing to contain high levels of these biogenic amines!
How about alcohol dehydrogenase deficiency…?
If it's redness of the face, slight dizziness and loss of equilibrium combined with sweating and a desire to sing karaoke, it's almost certainly an issue of alcohol dehydrogenase deficiency. The human body detoxifies alcohol in a two-step process. The first step is when the alcohol is attacked by alcohol dehydrogenase, which breaks it down into aldehydes or ketones. This is good, because if your body didn't break down the alcohol you'd be drunk for the rest of your life.
But it's also bad, because more than a little aldehyde in your blood is worse than alcohol. Aldehyde is pretty much nail-polish remover. Fortunately, your body has that all lined up, and another complex of enzymes called aldehyde dehydrogenase that break it down, eventually converting it into energy the body can use.
But you may belong to a sub-group of people who have less aldehyde dehydrogenase than others, and so you get stuck in between the two biological processes, with the equivalent of nail polish remover circulating in your bloodstream. People of northern European descent seem to have more aldehyde dehydrogenase than average, while people from southeast Asia can have less, though keep in mind individuals and groups vary in their response. But most of us have a friend who gets flushed and tipsy almost immediately after consuming even a small amount of alcohol!
With all of the above in mind …the best approach will always be to consume alcohol carefully, and within your own tolerance, and be sure to consume PLENTY OF WATER along with your drinks!
P. S.
Heard of ‘wine drops’, well these claim to remove the sulphites and reduce your headaches. What they are adding is hydrogen peroxide (H202) - the same hydrogen peroxide that is a bleaching agent, disinfectant and oxidiser. The addition of hydrogen peroxide (H2O2) to juice and wine, can be an effective treatment to decrease the concentration of free sulfur dioxide (SO2). This is permitted in wine production in Australia, and is an effective and safe procedure when performed carefully.
The hydrogen peroxide does indeed react with the free sulphites and removes them, but after a short period of time, the wine re-equilibrates and releases more free sulphites from the bound sulphites in the wine. However after application the new eqilibrium will represent a desired altered state, i.e. reduced levels of SO2. You can keep on adding hydrogen peroxide until there is no sulphite left, but every time you make an addition, you will also be ruining the wine by oxidising all the flavours and stripping the wine of all aromatics.
This blog was reconstituted from the below referenced sources for which I am very grateful:
https://www.thekitchn.com/the-truth-about-sulfites-in-wine-myths-of-red-wine-headaches-100878
http://www.morethanorganic.com/sulphur-in-the-bottle
https://www.wineaustralia.com/news/articles/know-your-sulphite-limits
https://www.winecompanion.com.au/resources/australian-wine-industry/label-laws
https://www.josefchromy.com.au/blog/sulphites-in-wine-a-common-question!
http://mastervintner.com/blog/lies-damned-lies-and-sulfites-the-facts/
https://www.midwestsupplies.com/bottled-knowledge/notes-on-winemaking/sulfite-allergies-the-facts