To sulfur or not to sulfur
Where I was educated in wine, sulfur dioxide was considered essential to quality winemaking.
We were taught that elemental sulfur had been used since ancient Roman times as a sterilant and preservative. It was and still is used widely to disinfect barrels and other vessels, to keep unwanted insects away from fresh grapes and juice, to prevent oxidation at both the juice and wine stages, and to keep out unwanted micro-organisms. Even ‘natural’ winemakers who eschew sulfur dioxide additions throughout the process usually relax their rule at bottling, which is when wine risks absorbing oxygen that may spoil it.
For quite a few years I’ve been tasting Australian ‘Preservative free’ or ‘No preservative added’ wines, and been impressed at how good and fresh these wines usually taste. They’re almost always reds: red wines have tannin and colour pigments that protect against oxidation. Unsulfured whites are usually brown in colour and smell and taste stale. If you don’t mind that, go for it.
The McLaren Vale area produces several excellent unsulfured reds: Yangarra, Battle of Bosworth and Inkwell have all impressed lately. None of them smelled at all aldehydic (acetaldehyde is the first sign of oxidation spoilage). I tasted a vertical of Bosworth’s Puritan unsulfured shiraz, back to 2010, and they seemed to be ageing normally (read my article here). How they fare in the long term remains to be seen.
But the wine that really turned my head was a chardonnay – a Corton-Charlemagne worth several hundred dollars a bottle, no less. It was a 2013 Domaine Ponsot which, according to my notes, was priced at AUD $835.
This was not only a superb wine, razor-sharp and crystalline in its flavours and aromas, it was as fresh as the proverbial daisy. It was three years old and sealed under Ponsot’s trademark closure, a synthetic Ardeaseal plug, which may or may not be significant.
Producers of unsulfured wines used to promote them as asthmatic-friendly. But I’m skeptical of making blanket statements about sulfur being dangerous to all asthmatics. I have several chronic asthmatics among my circle of friends and they all happily drink wine, including white wine (which usually has more sulfur dioxide than red). Others say SO2 in wine gives them headaches, but this is usually anecdotal.
The current trend towards low-input, minimal-intervention (did someone say natural?) wine is having many positive impacts on the conventional wine industry, and one is the questioning of some of the additions some winemakers have habitually made. If wine can be made without loss of quality by cutting back on or completely omitting sulfur dioxide, enzymes, acid and tannin additions, surely that’s a good thing.
As we seem to be seeing with the above-mentioned wines, just because our parents and grandparents did things one way, doesn’t mean it’s the only way.
A general guide to sulfur dioxide (SO2) levels in wine (highest to lowest):
- Sweet wines, especially very sweet wines (eg. Sauternes) and sweet wines in casks.
- Sparkling wines.
- Sweet fortified wines.
- Dry white wines and dry rosés – the sweeter they are, the more SO2.
- Dry red wines.
- Organic wines: SO2 is permitted but maximum levels are lower.
- NB. Cask (bag-in-box) wines contain more SO2 than the equivalent wine in a glass bottle.
- SO2GO: I have it from credible sources that this product works. You sprinkle a few drops onto your glassful of wine and it’s supposed to nullify the SO2. The active ingredient is hydrogen peroxide, which is very safe in these quantities. SO2GO is recommended for people with sulfur allergies or sensitivities. It’s sold in many bottle shops.
*First published in Gourmet Traveller Wine magazine, June-July 2017.