Summerhill Vineyard
Organic winemaking has come a long way. For those who enjoy a glass or two, the modern practices are being investigated to improve the ancient beverage are welcome advancements.
At Summerhill Pyramid Winery in Kelowna, winemaker and viticulturist Eric von Krosigk, was experiencing symptoms many wine drinkers encounter, but perhaps chalk up to “bad wine” or “one glass too many.”
“I noticed I was becoming a little more sensitive to sulphur,” von Krosigk notes. “This is my thirtieth year in winemaking and I’m more motivated by my own pure interest, but certainly there is a market there (for sulfite-free wine).”
Sulphur can combine with many different elements and compounds. When it is by itself it is the element sulphur, but when mixed with other elements or compounds they collectively are known as sulfites.
So that nasty headache, congestion, red cheeks or other symptoms may be due more to sulfites than anything else. The problem isn’t necessarily “one too many,” but one too many with sulphur.
Sulphur dioxide is added to wine as a preservative to prevent bacterial spoilage. Debates about sulfites rage on, but Health Canada states sulfites are among the top 10 priority food allergies. How much is too much is a personal thing: those with asthma and anaphylactic issues are at the greatest risk, while others may simply experience a hangover sensation.
For that reason, regulations are somewhat vague. Wine containing more than 10 mg per litre of sulphur dioxide must be labeled as “containing sulfites.” Unfortunately, there is no way of knowing how much the vintner has used beyond the 10 mg/L.
Interestingly, the World Health Organization suggests a maximum daily intake of 0.7 mg of sulphur dioxide per kilo of body weight. Given that the average Canadian woman weighs 66 kg (145 lb.), at 10 mg/L it means the average ‘she’ could consume 4.6 litres of wine before going over the WHO limits.
At that rate alcoholism will become a problem long before sulphur dioxide intake does, but this is misleading since the sulphur dioxide levels could be 10mg/l or 200 mg/l. At the high end, instead of 4.6 litres of wine, the average woman would go over the maximum suggested amount at 0.23 litres of wine, which is approximately eight ounces.
“The vineyard (at Summerhill) has been organic for a very long time,” comments von Krosigk. “Right now we make about 28 different wines – reds, whites, sparkling and desserts.” All the Summerhill grapes are from B.C. and are organic except one varietal.
Summerhill began organic practices in 1988, with organic grape certification being achieved in 1995 and organic winemaking certification in 2007.
Don’t think organic wine means an absence of sulphur. For the most part, it doesn’t. There is wine made with organic grapes, then there is organic wine – meaning the majority of the ingredients (including, but not limited to the grapes) are organic, then there are organic processes for bottling.
“We researched a lot of systems,” says von Krosigk. “Nitrogen was used years ago, but fell out of favour to other gases.” Including the now pervasive sulphur dioxide.
Through a program funded in part by the Investment Agriculture Foundation of British Columbia, Summerhill, already the largest organic winemaker in Canada, is taking organic wine making further by incorporating a nitrogen generator into the processing. Summerhill’s 2012 harvest has been bottled with little to no added sulphur dioxide.
Sulphur is used in the wine making process to “bind up” the oxygen, according to von Krosigk. There is always a tank that is only partially filled with wine, therefore more oxygen than desired makes up the balance of the tank.
Oxygen is necessary for bacteria to grow, and in certain temperature ranges bacteria grows even faster.
The solution was to fill the non-wine occupied section of the tank with nitrogen to displace the oxygen. Replacing oxygen with nitrogen prevents bacterial growth, regardless of temperature, so using nitrogen can reduce or eliminate the sulphur content and climate control becomes unnecessary, thereby saving energy.
“We came up with this nitrogen system and modified it to our own use,” said von Krosigk. “We take it right out of the air and pump it into the tanks at one PSI. Just enough to push out all the oxygen.”
Of course, the taste of the wine still holds the cards, so to speak, and while Summerhill will make wine without sulphur wherever possible, the odd case may require small amounts.
Plumbing nitrogen directly into the tanks and applying constant low pressure is, as far as von Krosigk knows, a first for a B.C. winery. He is hoping that proving the nitrogen generation system will benefit all winemaking, organic and conventional. In addition, it will improve the enjoyment for those who have a sulfite sensitivity.
“Right now, it’s doing exactly what we’d hoped it would,” von Krosigk says of the nitrogen system. “Plus it’s not out of reach as far as costs.”
Early results of the three year study are promising.
“It creates wine with a longer shelf life that is brighter, fresher,” he notes.
Research and experiences from the testing will be posted on the Summerhill blog at http://www.summerhill.bc.ca, as well as in a report that will be shared with the industry soon.
Research results so far have already been chronicled on the Summerhill blog. Von Krosigk says everything from the process will be documented, from research to itemization, procedures to suppliers.
“It will be a very transparent process and transferable,” he comments. The whole industry must benefit.”
