words Jack Swann & Moira Tirtha
illustration Sophie Weedon

Natural and minimal intervention wines have been eliciting conversations about what actually is in wine. There’s word going round that natural wine doesn’t give you hangovers and attributing this phenomenon to sulfur, or lack thereof, has become a widespread and divisive topic. Our bodies; the intricate meatsack burdened with consciousness, so desperately loves to seek out simple answers and latch onto clickbait-esque generalisations. In an attempt to neatly categorise and make sense of our experience, bad wine hangovers or allergy-like symptoms on a night out, have quickly turned into a rise in claims of a sulfur allergy.

Now, we’re not out here trying to tell you how you feel in your body. And hell, if anyone is trying to do that, they can truly rack off. That being said, once you start doing a bit of reading into wine allergies you’ll discover just how different reactions can be. This read isn’t going to cover everything, but we hope to revel in the mystery; the complexity that is wine. Much of the science can still be debated, but hopefully we can help some of you make sense of what might be happening in your body if you do feel badly after drinking wine, both natural or conventional, and help you feel your best when you do.

So, What Even Is Sulfur?

At its simplest, sulfur is a chemical compound used as a preservative. It’s used in a wide range of products; cured meats, softies and canned food. It acts as an antimicrobial and antioxidant agent. But of all the 86 allowed additives in Australian winemaking, sulfur is the one that sets off alarms in people’s minds. Why? For starters, it's one of the only things that legally has to be listed on your bottle.

In Australia, sulfur quantities in wine are regulated to a maximum of 250ppm (parts per million) and 300ppm for sweetie treaties (think fortifieds). However, some organic and biodynamic certifications restrict this down to 150ppm. That being said, the quantities used in winemaking are pretty darn low in comparison to other foods. The classic example is dried fruit, where more than 2500ppm can be used, or in hot chips where you can find up to 1500ppm.

In minimal intervention winemaking, you’ll often see ‘minimal sulfites’ on the label. Minimal sulfites is a whole convoluted mind-fuck philosophy/dogma/meme of a thing in natural vs. conventional winemaking and we’re not going to bother with that here, but you should know that as a term, ‘minimal sulfites’ doesn’t mean anything in Australia. You’d hope for less than 30ppm, but it could really be 249ppm. NB: since it’s a byproduct of fermentation, there’s actually no such thing as a 100% sulfur free wine anyway. This is why we think label transparency is important.

In the winery, sulfur is typically used in two forms; in solid form as potassium metabisulfite (PMS) or in gas form as sulfur dioxide (SO2). Preservative 224 refers to use of the former whereas preservative 220 refers to the use of the latter.

But hey, let’s set the record straight. Sulfur is toxic as a gas and a great irritant in solution. Fears around its use are justified; it affects your body’s respiratory system. When you’re working in a winery and mixing up sulfur to use, you get some nasty coughs. And when you drink enough wine with elevated SO2 you can, in fact, taste it, or at least sense it. It changes the texture of the wine, a tightening in your chest, a sharpness in your schnoz. 

Sulfur’s job is to prevent undesirable flavours in wine caused by unwanted microbes. Sulfur preserves colour in wine and prevents browning by inhibiting the activity of an enzyme that facilitates oxidation. It helps prevent wine ‘flaws’ such as brett, mousiness, oxidation, and volatility. It also stabilises wine, meaning they last longer when opened, and can make it across the world for export without going dank. This isn’t to say that sulfur free wines can’t be stable; it just means it’s a whole lot harder. It takes extremely high quality grapes and careful winemaking.

Depending on the degree of natty to straighty conventional wines, sulfur is added at different parts of the winemaking process. It’s all very subjective though, and how every winemaker defines ‘natural’ through the lens of sulfur use varies from person to person.

Allergies, Intolerances & Sensitivities

The words, ‘allergy’, ‘intolerance’ and ‘sensitivity’ get thrown around a lot. They’ve become interchangeable; casual shorthand for any adverse reaction our body experiences. However, there’s actually quite a difference between them and it’s something we need to talk about here. Intolerances occur if your body is unable to metabolise something. This is often due to enzyme deficiencies (e.g. lactose intolerance is the inability to digest lactose – it’s not an allergic reaction to lactose). As such, intolerances don’t always result in an immune response. Allergies do. Symptoms depend on where and how your body is exposed to the allergen, but typically they’re the same – rashes, hives, difficulty breathing, coughing, headaches, swollen lips and sinuses – think peanuts and bees.

In the middle we’ve got sensitivities, which usually refers to a mild intolerance – symptoms here vary and underlying causes are often pretty murky. Confusion occurs with sulfur in wine because it gets exposed to our airways when we’re drinking it. A sulfur sensitivity, or intolerance, will result in difficulty breathing – a symptom that overlaps with allergies. But, a GP won’t be able to diagnose you because there aren’t definitive tests, you’d need to see an immunology specialist and go through a whole process of elimination regime.

It's estimated that up to 20% of the population suffers from some form of allergy or intolerance, but the percentage of people who are known to actually react to sulfur are far fewer (like actually next to nothing), although because some people do, it’s why there’s a requirement to label food with more than 10ppm of sulfur.

As we’ve noted, minimal intervention wines can still have a chonk of sulfur in them and overall there tends to be more sulfur in white wine compared to red. So bottom line, if you have a reaction to one and not the other, it’s likely not sulfur.

“Looking at it under a microscope, natural wine looks like a small universe.”
Gilles Verge

Microbial Fingerprint

Natural and biodynamic foods (not only wines) tend to rely on letting nature do what it needs to do. While this is great in theory, it’s pretty hard to apply this principle everywhere we go. In writing this article we’ve actually become much more interested in bacteria than we have in sulfur. For every human cell in your body, there’s 10 bacterial cells living with it, on it, around it. Only about 5% of known bacteria cause disease; the rest kinda just hang out and a lot of them are actually advantageous to have – so stay cultured and check in on your gut flora every once in a while. Most human intervention (i.e. preservatives such as sulfur) attempts to prevent people from getting sick due to the presence of unwanted bacteria – you only need to look at how many people they’ve killed over the years. Anyway, what’s important to note is that the role of bacteria in our everyday lives is so often overlooked. Perhaps this is simply because we don’t see it on the day-to-day.

Every wine carries its very own unique microbial fingerprint, that is, a complex set of chemicals and compounds. We readily experience this when we drink wines from different regions, vintages and wineries – sugar, acid, tannin, phenolics, alcohol – but what of the things we don’t necessarily taste? Every decision in winemaking will alter its chemical makeup – filtering, fining, preservatives, processing aids, foreign yeasts, pesticides, accidental insects, smelly feet … so on. It’s so difficult to pinpoint any one specific allergen because all of these things can potentially set you off. A lot of fining agents use fish and egg products – one of the only other things you sometimes see on labels.

Bacteria and yeast play such an important role in determining the outcome of this microbial fingerprint; grape skins are naturally swarming with both of them. And considering that red wines tend to be responsible for more allergies than whites, we can look to their two biggest differences for potential explanations – skin contact and malolactic fermentation.

Biogenic Amines & Histamine

One outcome of bacterial activity on grape skins is the production of these compounds called biogenic amines, the most notable of these is histamine, which is found in high quantities in red wine. Histamine is the biological alarm sound that sets off your immune system – it’s natural. Your body releases it when you have an allergic reaction, although everyone has a slightly different threshold for this to occur. The high concentration of histamine in red wine has been found to be enough to tip some people’s immune system over the edge, where they end up getting allergy-like symptoms – blocked nose, tight chest, headache and so on. 

Malolactic fermentation, a process that happens in reds, is said to play a big role in increasing histamine concentration. This is likely due to the additional cultures added to the mix, but there’s still debate over which strains of bacteria are responsible. But, hey! Notice, bacteria – histamine – allergies, little to do with sulfur.

And yes, there are foods out there with higher amounts of histamine compared to wine, but what may make red wine the big allergy inducing culprit is the complex interplay of other wine components with histamine (we’ll get to this in a second). What’s convenient though is that some red wine allergies can be relieved by an antihistamine.

You can stop reading now if you like. Go away, try an antihistamine, read into low histamine diets. If it works – great! If not, it could be something else, we might be wrong entirely, or, it might be what we’re about to discuss. Either way, it gets a little more convoluted from here on in.


Let’s start off with the mother of all. Water. We all know that alcohol makes you pee lots. But why? It stops the function of an enzyme called vasopressin. Vasopressin acts in your kidneys, it’s the signal that yells, ‘keep water in me!’, when you’re out drinking this signal stops and your bladder just starts pissing everything away.
But have you ever noticed that you feel more thirsty after drinking wine compared to other alcohols? Waking up in the middle of the night with the mother-in-law of all dry mouths?

Tannins aside, your body functions on this neat balancing beam of stuff dissolved in water. The measuring stick for this is called osmolality – you may have also heard of osmotic pressure or homeostasis - anyway, we can see some numbers below:

Look at how much shit there is in wine! You’re looking at alcohol, tannins, acid, sugar, phenolics, preservatives, biogenic amines just to name a few, plus an array of various other byproducts of fermentation. For reference, beer, most juices, soft drinks and other beverages are usually well below 1000mOsm/ kg. Isotonic sport drinks are about 300mOsm/ kg (i.e. the same as blood). Grape juice is about 1200mOsm/kg even before fermentation, after which it gets up to 2500mOsm/kg! It’s a dense microbial fingerprint to say the least. But here’s the thing. In order to process drinks with high osmolality your digestive system needs water. When drinking beers, or mixers, your body is able to use more of the available water in the beverage itself to balance things out, but with wine, it’s possible that your body has to absorb water from elsewhere (especially if you’re not knocking back a glass of water every now and again). Some experiments also indicate that darker drinks are responsible for worse hangovers due to the increased polyphenol concentration.

In some respects this riot of a microbial fingerprint is awesome. When exploring the health benefits of wine consumption many studies look at its activity in your digestive system. We’ve found its antioxidant and anti-inflammatory benefits, which are said to come from the interplay between wine phenolics and bacteria in the gut. However, in the event that some of your body’s excess water needs to be sucked into your digestive system, there’s going to be less water heading out to the rest of your body’s networks. This becomes even worse when you drink the cheap and sweet stuff too. More sugar will yield a higher osmolality wine, which ultimately leads to higher glucose in your bloodstream. Likewise, when you’ve got large amounts of stuff moving into your blood your body tries to balance it out with water, which of course you end up losing when vasopressin isn’t telling your body to, ‘hold it all in.’

Vasopressin activity is also dependent on alcohol concentration, so again, wine and spirits will have a worse effect compared to beers and mixers etc. Obviously it’s always highly dependent on whatever else you’ve been eating and drinking and your body type and gender and age and metabolism and star sign. But what’s the worst thing about being hungover, sick or better yet, having an allergic reaction? Being dehydrated. These things add up.

Histamine Intolerance & Diamine Oxidase (DAO)

Now, to add to the chaos, alcohol can also make histamine stay in your body for longer than usual. It does this by suppressing an enzyme called diamine oxidase, or DAO, which is responsible for breaking histamine down. What’s more is that other biogenic amines also interfere with DAO activity. As a result of all this, histamine might continue to run rampant throughout your body, meaning your immune system would be activated for a longer period of time. What’s even more alarming is that deficiency in the DAO enzyme is becoming increasingly prevalent in our population (we're seeing up to a 9% increase in some autoimmune diseases each year, western countries are much worse for it too). Having this deficiency means you’re likely to get more severe allergies to begin with. It means you’re ‘histamine intolerant’ or ‘histamine sensitive’, which manifests exactly the same as an ‘allergy’ – remember the difference? The symptoms here are basically the same because what you’re intolerant to is the alarm that sets off your immune system. Mayhem.

And again you’re a blip on each of these spectrums of severity, but the problem with histamine and sulfur sensitivity, wine allergies, DAO activity, bad hangovers and dehydration is that so many of the symptoms overlap and it’s very difficult to tell which ones are, or aren’t, happening.

Natural Wine & Hangovers

We’d love to say that natural wines don’t give you hangovers but it’s just not true. Any alcohol will give you a hangover if you drink enough of it, and the only real cure is time. Pretty well all hangover symptoms are credited to acetaldehyde; the toxic byproduct of alcohol metabolism. It’s got a whole range of carcinogenic properties, plus memory loss, headaches and facial flushing. If you’ve ever heard of ‘Asian flush’ this is due to an inherited enzyme deficiency, resulting in acetaldehyde intolerance (i.e. the inability to break down acetaldehyde). You could add this to the diagram below, acetaldehyde has been found to stimulate histamine production in some individuals too.

Also, while we’re at it, there’s little chat about ABV in wine. A bottle of wine is just a bottle of wine, right? Well, like nah though. Natural wines, or glou-glou wines, are typically lower in alcohol. If you’re drinking an 11% natty instead of a 14% dad shiraz it’s about the same as replacing your 6-pack of full strength beers with mid-strength. It’s going to make a difference to how you feel the next day.

Concluding Thoughts

Everything up until now has got pretty solid research behind it, but we need to be careful drawing conclusions, as we know, everyone is different and we’re not here to tell you what you’re feeling is wrong. What we know is that all wines carry their own distinct microbial fingerprints, and it’s something within that which causes allergies, or intolerances. The population could in fact be more sensitive to sulfur than we think. Or, we could be reacting more to byproducts of fermentation and bacterial metabolism – which is the case for biogenic amines and anything histamine related. This is higher in red wines, compared to whites, probably due to skin contact (maybe a bit of malo). But most natural wines have this as well, only they’re meddled with a lot less and we don’t hear of many allergies towards them, or know much about their histamine concentration. This could indicate that conventional wine allergies may instead be due to the chemical changes brought out by human intervention – and we’re back to sulfur. Since sulfur has such a drastic effect on microbial activity (hence fingerprint) how can we expect it to not impact our reaction to the wine?

The rumour that sulfur is what causes our hangovers caught on like wildfire because we all want a get-out-of-jail free card for our hangovers. But, this so-called myth is so widespread because there’s actually a lot of validity to it. It’s just likely we’ve overlooked the complexity, cut out our bacterial friends and not bothered to talk about it at all. Delivering blame isn’t always helpful in these situations and it especially doesn’t help when we’re sold products to counteract this thing that might not even be happening in the first place (looking at you, SO2GO spray). Wines change over time. There’s constant microbial activity happening and their fingerprints continue to evolve as compounds form and diverge with one another. But, if you’re wanting a simple answer, when spending good money on natural, biodynamic or minimal intervention wines, chances are that the winemaker has taken a hell of a lot more care in their craft. Fewer additives, random yeasts, enzymes whatever have you — just the locals having an absolute ball. Sulfur aside, what we know is that drinking wine (reds particularly) can activate your immune system, dampen your ability to stop it and dehydrate you more than other alcoholic beverages. Add that to a hangover and it’s no wonder some of us feel like trash.

On Sulfur was originally published in Volume II of Veraison. Volume II is available to purchase here.
Veraison is largely created on the lands of the Wurundjeri people of the Kulin Nation. We pay our respects to their Elders past, present and emerging, whose connection to land is far deeper and far more historic than ours.