Ask Wine Wizard

Volatile Acidity Fixes


Mary Rogan — Auckland, New Zealand asks,

Because of travel restrictions over the past few months, I was unable to rack my 2019 (New Zealand) Pinotage from a Speidel plastic fermenter to the stainless container or adequately manage sulfite levels (basically I was unable to travel back from the U.S. to New Zealand until recently). I could taste volatile acidity (VA) and sent the wine off for testing:

I have read that the legal threshold for VA is 0.7 g/L and blending is the best solution. So far, I have added another 1 g/L of tartaric acid and bumped up the sulfite to 75 ppm. Unfortunately, I don’t have any blending wine. It is OK to drink, especially with food, so I am reluctant to dump it. Do you have any suggestions? I don’t normally filter my wines — should I pass through a sterile filter before bottling, any other way to reduce the VA or minimize the sensory impact and can I prevent it deteriorating further?

A Sadly, blending VA levels downward remains the only option available for reducing VA content in small lots. Larger commercial wineries, with big lots and bigger pocketbooks, can afford the expense of reverse osmosis and distillation technology to remove it from their wines but there’s no affordable option for small producers. Simple filtration doesn’t work to remove VA, though sterile filtration can certainly remove the spoilage yeast and bacteria that may be contributing to it. The good news for you is that your VA levels are nowhere near approaching legal limits. The legal limit for VA in the U.S. is actually 1.1 g/L for white wines, and 1.2 g/L for red wines. At these levels, I indeed do find the wine objectionable. Sensorially, at 0.6 g/L, you should be within a tolerable range, especially for a wine that is already a year old. VA tends to climb with time and even though you had a moment during the wine’s lifetime where you weren’t able to keep the SO2 levels up in ideal ranges, it’s actually not that bad. It is
Response by Alison Crowe.