Sulphites in wine – maximum and typical concentrations

In pretty much all wine-producing countries, there are regulations to limit the sulphite content of wine. The limits are always expressed nominally in terms of total sulphur dioxide, but I suspect they all assume an analysis method that fails to account for some of the bound sulphur dioxide, as discussed in my previous post.

Let’s start by taking a look at sulphite limits in the European Union. The rather complex set of limits are very nicely summarised in a table in the document EU rules for organic wine production: Background, Evaluation and Further Sector Development:

If you feel motivated to check these various EU limits or get more details, the table provides you with the relevant document numbers, which can be found by a web search. But it is not a task to be tackled lightly – I once set out to extract the various sulphite limits from the 1999 regulations and nearly lost the will to live.

The US regulations on the other hand have the advantage of simplicity: for wines with no organic-credentials the limit is 350 ppm (or mg/l – the units are practically identical). That figure is widely quoted, but I am afraid I have not been able to track down the actual regulatory document. I had more success with finding an authoritative-looking document for organic wines in the USA: Organic Wine: Oversight, Labeling & Trade. That document covers two categories: wine made with organic grapes and organic wine, where organic wine has stricter rules. For organic wine, added sulphites are not allowed at all – though the wine will still contain naturally occurring sulphites, and probably need a sulphites warning on the label, as discussed in my previous post. However, for wine made with organic grapes sulphite additions are allowed, providing there is no more than 100 ppm sulphur dioxide in the finished wine. In the EU by the way, wine made with organic grapes is not a special category: the grapes must be farmed organically as claimed, but all winemaking regulations are as for conventional wines in the above table.

For allowable sulphite levels in other countries, The Oxford Companion to Wine reads: “In South Africa, the limit is 150 mg/l for dry reds, 160 mg/l for dry white, rosé, and sparkling, and between 200 and 300 mg/l for sweet wines depending on style and level of sweetness. Argentina: 130 mg/l for dry reds, 180 mg/l for dry white and rosé wines and sweet reds, 210 mg/l for sweet white and rosé. Chile: 300 mg/l for all dry wines and 400 mg/l for sweet wines.”

As far as biodynamic wine is concerned, Demeter certifies it internationally, and their document Standards for Demeter/Biodynamic Wine regulates the use of sulphites. The stated aim is that sulphur dioxide be restricted to the absolute minimum, but then the document proceeds to specify limits that are more lax than the US organic regulations. For different types of wine, the maximum allowable total sulphur dioxide at bottling in mg/l is:

But what about so-called natural wines? As you probably know there is no official definition or certifying body, but we can take a look at the list of wines made by the accredited growers and makers of Raw Wine – Isabel Legeron’s platform for the promotion of natural wines. By searching the list using filters provided on the website, it is possible to get a feeling for sulphite levels in wines deemed to be natural. The database also records which wines have added sulphites, but sadly you cannot use that as a search criterion. Here are the results of a search on 6th June 2019:

Total sulphur dioxide (ppm) Number of wines
0 468
1-10 925
11-20 929
21-30 957
31-40 739
41-50 504
51-60 341
61-70 196
71-80 5
81-90 2
91-100 2

I think some of the quoted sulphur dioxide analysis results in this table need to be taken with a pinch of salt. For example, when you look at the data in more detail it is obvious that some testing laboratories round the concentrations to the nearest integer multiple of 5 or 10 ppm. Note also the high number of wines with precisely zero sulphites, despite it being commonly stated that fermentation necessarily creates sulphites in all wines. I have seen 10 ppm referred to as a detectable level, implying that measuring anything less than that is problematic, so perhaps that explains all the wines at 0 ppm? But regardless of such quibbling, I think we can conclude from the table that most natural wines contain less than 40 ppm, and that there are fewer and fewer natural wines at levels increasing from 40 to 70 ppm.

So now we know the sulphite concentrations in some natural wines, thanks largely to sulphites being one of the obsessions of the natural wine community, but getting sulphite concentrations for wines in general seems to be more difficult. The assumption is often that the makers of cheap wines zap their wines with as much sulphite as they can get away with, to compensate for poor fruit quality, and for closer control of the winemaking process to create a consistent product that meets an expected flavour profile. On the other hand, higher quality producers are expected use less sulphites, as they take more care to select healthy fruit, are willing to put more effort into low-intervention winemaking, and are also more tolerant of variation in the end product. I personally think there must be some truth in that characterisation, but sadly cannot demonstrate it with numbers. More certainly, it is the case that red wines need less added sulphites than white, because the tannin in red wines will also provide protection against oxidation, and sweeter wines will tend to need more added sulphites, because the sugar binds sulphur dioxide, rendering it a lot less effective.

To get some feeling for typical sulphite concentrations in wines that are not claimed to be natural, I think we could do a lot worse than look at the maximums in the first table of this post. EU regulations are typically designed to reflect existing practice rather than to effect change, so I think it is reasonable to assume that most wines have sulphite levels approaching, but comfortably within, the specified limits for the different styles of wine. On the other hand, producers who particularly favour low-intervention methods (even if they do not identify with the natural wine movement) would be closer to around 30 ppm, and other high-quality wines would have intermediate concentrations.

So what are we to make of all this? To be honest I am not at all sure. One might hope that maximum sulphite levels were specified according to some sort of objective assessment of health risk, but I am not convinced we know enough about sulphite allergies to do that – there is not even agreement about what proportion of people are affected by sulphites (as mentioned in my previous post). So what we have are rules based on a mish-mash of current practice and ideology. In my opinion, the best that can be said for the current situation is that consumers can exercise a degree of choice about their exposure to sulphites – based on their world-view and how they personally perceive health risks.

How important is a rich soil ecology?

Intuitively for most people, a vineyard with grass and wild flowers between the vines is regarded as a Good Thing. It looks pretty, and is indicative of a healthy ecology that has not been destroyed by pesticides. A vineyard soil teeming with life can be an end in itself, and an important benefit of sustainable viticulture. But however good for the environment it may be, is a rich soil ecology critical for good wine?

By way of example, here are images of vineyards that have a lot in common, and yet are totally different. They are both on islands in Southern Europe, and both have volcanic soils. The first one is a vine on the island of Santorini, where the soil has been created by man tilling tuff (a rock of compacted volcanic ash) to a depth of half a metre or so. I only show a small area of the vineyard in the image, but it is typical of the island in that there is little or no vegetation, and the soil has very little organic matter. Lack of water, not over-use of pesticides, is the reason for this barren soil. The other image is from the Northern slopes of Mount Etna. Here there is more water, and nature has had more time to work after the most recent lava flow in the area. So there on Etna, the organic farming methods employed in the vineyard result in a much richer biodiversity – which would also be expected in most parts of Europe.

As for the wines from both these places, I think most people would agree that they are good if not excellent. I do not know where the grapes from that particular Santorini vine would finish up, but the soil is typical of the island and Santorini wine is generally of high quality, and the vineyard on the right is owned by Tenuta delle Terre Nere, one of the most highly regarded Etna producers.

So from these examples can we conclude that organic matter in vineyard soil is not necessarily so important? And that good wine can result from soils both rich and meagre? More contentiously, perhaps even soils poor from the over-use of pesticides can result in good wine? Or could, for example, Santorini wine be vastly improved by applying compost, most of the ingredients for which would need to be imported? These are not totally rhetorical questions – I would genuinely like to know, and I suspect the answers are not as clear-cut as some would have us believe.

Natural Wines from Les Caves de Pyrène

Less than a week after wine lovers daarn saaf were enjoying RAW and The Natural Wine Fair, a few of us oop north were doing our bit to better understand what natural wines have to offer.  My methodology was to ask Les Caves de Pyrène to suggest a mixed case for a tasting, leaving them to define the term how they wanted and send me a representative sample.  These wines were not review samples, but paid for in the normal way – in this case, effectively by the local tasting group I belong to.  In addition to the wines tasted and described below, the Occhipinti 2011 Bianco and Rosso were also suggested and purchased.

We kicked off with five whites. The empties are shown above on our 100% herbicide-free lawn.

Vernaccia di San Gimignano, Imprompta, Mattia Barzaghi, 2010, 12.5%, £10.73
Pale straw. Intense, fresh, floral. Yoghurt. Medium high acid. Dry. Clean and refreshing. Excellent length. Drink now. Very pleasant. A solid ***

Val du Loire, Sauvignon, Hervé Villmade, 2011, 13.0%, £9.65
Pale gold. Intense.  Ashtray – in a positive way! Fresh. Hoppy aromatics. Medium acid. Dry. Gooseberry. Subtle. Excellent length. Incense-like woodiness. Drink now ****

Vin de Savoie, Les Alpes, Gringet, Dominique Belluard, 2010, 12.0%, £14.63
Medium pale gold. Intense and full. Apple. Banana. Medium acid. Dry. Excellent length. Caramel. Drink now ****

Montlouis sur Loire, Minéral+, Un Saumon dans la Loire, 2011, 13.0%, £13.67
Medium pale gold. Over-ripe apple – oxidised. Medium acid. Flat, and lacking fruit. Drink now **

Chablis, À Chablis, Le Vendangeur Masqué, 2010, 13.0%; £14.87
Medium pale gold. Vaguely citrus. Medium high acid. Dry. Apply too. Fresh and tingly. Drink now ***

Then we moved onto the reds. These were also double-decanted not long before the tasting to take the wine off all sediment I was expecting from these possibly unfined and unfiltered wines. It turned out there was very little sediment.

Beaujolais, Yvon Métras, 2010, 12.0%, £14.45
Medium pale ruby. Intense fresh red fruit. Juicy fruit. Pinot Noir nose.  Medium+ acid. Excellent length. Low tannin. Drink now ****

Saumur Champigny, Domaine des Roches Neuves, 2011, 13.0%, £11.03
Intense purple ruby. Intense fresh blackberry. Medium high acidity. Low tannin. Fresh and juicy. Excellent length. Drink now ***

Côtes du Rhône, Les Romanins, Domaine Ferme Saint-Martin, 2010, 13.5%, £9.41
Medium purple ruby. Baby nappies and cheese – again in a positive way! Some red fruit too. Medium high acid. Rather nice. Elegant. Subtle. Excellent length. Drink now ****

Coteaux de Langedoc, Montpeyroux, Domaine d’Aupilhac, 2009, 14.0%, £13.43
Intense purple. Intense dark fruit. Oak. Medium acid. Medium low tannin. Drink now. A rather conventional wine ***

Cannonau di Sardegne, Mamuthone, Guiseppe Sedilesu, 2009, 14.5%, £15.47
Intense purple ruby. Intense raisiny. Slightly oxidised.  Medium+ acid. Rather nice and elegant. Medium high tannin. Refreshing. Fantastic length. Good to drink now but will probably improve over the next years.  Maybe I was over generous, but as this wine made the biggest impression on me, it gets *****

Polishing off the remains the following evening confirmed to me that the Loire Sauvignon and the Vin de Savoie were my favourite whites.  And the fact that all the reds apart from the Côtes du Rhône disappeared on the night of the tasting shows which wines were the most popular amongst the whole group!

As far as I can make out, all of these wines were made from organic or biodynamic grapes, fermented by ambient yeasts, and with minimal sulphur additions. All labels bore the “contains sulphites” text, but that could required for the low levels of sulphur that result solely from the fermentation process.

I did not experience any of the natural wine horror stories occasionally mentioned by others – everything we tasted was recognisably wine, and definitely not slightly fizzy cloudy cider.  The only faulty bottle was the Mountlouis, and to be fair there were those at the table who enjoyed that too.  The Côtes du Rhône was a tad bretty, but for me it was at a level that added to rather than diminished the overall experience.  Oh, and there was one wine (can’t remember which one) that had obviously undergone some secondary fermentation in the bottle as it let off a fizz when I opened it, and was initially a bit spritzy, but by the time we got round to tasting it all signs of pettilance had gone.  Really, I don’t think the absence of faults was too surprising in that I suspect the winemaking was not that different from the vast majority of what I would consider to be good wines.

Generally speaking, the wines seemed to go down well at the tasting.  One comment I got was that the wines were “gentle” – no hard edges.  I certainly thought they were enjoyable, but I was not sure about the idea propounded by some that natural wines allow the terroir (or the grape variety, depending on who you speak to) to shine through.  I was getting a lot of flavours that I am feeling were probably due mainly to the natural fermenation.  If we had tasted blind, I would have struggled more than usual to identify varieties and regions.  That certainly has a positive side – if I had to trade typicity for interest, I would go for interest most of the time.  But even I sometimes like to know what to expect when I open a bottle.

Organic roots

This is intended as a short follow-up post to The roots of biodynamics, where I started off by saying that wine drinkers tend to think of biodynamic wine production as organic with bells and whistles.

That may be true, but it is very much putting the cart before the horse. Steiner’s lectures in 1924 pre-date the modern organic movement, which emerged in England in the 1940s. Thus, it seems to me that the more practical ideas of the organic movement became part of the cannon of biodynamic practitioners as a later addition, rather than organic farming being the solid foundation for the magic sprinkle of biodynamics.

I don’t really want to go too much into the history and philosophy of organic farming, other than to make the point that it stemmed from the study of traditional agriculture practice, and thus is very different to the spiritual theories of Steiner.  Sir Albert Howard, known as the father of organic farming, is illustrated above.  The organic movement certainly has a strong ideological aspect to it, but essentially it is the product of rational thought, and compared to biodynamics is much more amenable to scientific enquiry.

Just one final thought.  I have recently come across a number of sources that claim that the ideal of the farm as a self-sufficient organism is one of the ways in which biodynamics is superior to mere organic farming.  Don’t believe it!  How many wine producers have access to cattle and red deer on their own land, for the various biodynamic preparations?  Some vineyards do not even have cattle in the same region, as the landscape is more suited to sheep and goats.  Besides, the concept of the farm as a self-sufficient organism is very much owned by the organic movement – ever wondered why it is called organic?