Carbon Emissions Are Getting You Drunk

What impact are greenhouse gasses having on wine drinkers?  For one thing, they’re getting us loaded. 

In the 1980s, wine averaged 12% to 12.5% alcohol.  Today the average is 13.5% to 14.5%.[1]  We learned why in high school biology.  Think back to the photosynthesis formula:

CARBON DIOXIDE + WATER  >>  SUGAR + OXYGEN

Carbon dioxide levels are at their highest ever reported.[2]  This means plants have tons of inputs to make sugar, and grow faster.  But this reached a natural limit, and plants are now replacing other nutrients with… more sugar.  Generally, this means our plant-based food is more carbohydrate-rich and less mineral-rich.[3]  For wine, this means more alcohol. 

To develop proper tannins and flavor, winemakers must leave the grape to ripen on the vine.  However, these growers have increasingly noticed that sugars are forming earlier and earlier in a grape’s lifecycle.  This means that more sugars are accumulating over time.  During the fermentation process, these sugars convert to alcohol, and overwhelm the wine.[4] 

Some winemakers accept the compromise and pick the grapes earlier, sacrificing flavor and tannins and embracing high-acidity for low alcohol content.  Others allow the grapes to stay on the vine so long the phenolics become heavily concentrated, then add acid later.  This is seen as a highly intrusive strategy, but one that is popular in warmer regions.  And some winemakers just add water.  Chile, concerned about the potency, recently altered their rules to allow adding up to 7% water and this practice has long been allowed in California.[5] 

Technology may be able to mitigate some of these effects, but next time you’re three sheets to the wind, blame the CO₂.

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[1] https://www.ft.com/content/ea9bda5c-c82f-11e4-8fe2-00144feab7de

[2] https://climate.nasa.gov/climate_resources/24/.

[3] https://www.politico.com/agenda/story/2017/09/13/food-nutrients-carbon-dioxide-000511

[4] https://winejournal.robertparker.com/rising-alcohol-in-wines-and-rising-co2-levels

[5] https://www.ft.com/content/ea9bda5c-c82f-11e4-8fe2-00144feab7de