I wrote this blog back in 2010 originally. For the record, I haven’t had to deal with oxidized wine since that time. Recently, I’ve been asked about correcting a wine that has oxidized. So, I dug it up and revised it a bit and here it is. Hope it helps.
If you are diligent in tending your wine, you may never experience oxidation. However, if you are like me and tend to experiment a lot, you might have more wine going than you can sometimes keep track of. While a balanced wine generally takes care of itself, sometimes I may check in on it a little later than I should. Meanwhile, perhaps the S02 levels may drop while I’m not looking. But let me be clear, I definitely won’t neglect my prize batches.
The reality of the situation is, I keep a cellar that is like a big test tube of experimentation. They say a good winemaker has a lifetime of experience. I believe that. My goal is to pack in more experience in less time to produce a better wine, sooner. So I experiment a lot and log everything.
I have experienced oxidation a time or two. The best way to describe oxidation is to cut up an apple and watch within seconds while it turns brown. Air is the enemy to wine. Air is also our enemy. Funny, we need it, but it too wears out our bodies and makes us grow old. There are several factors that can oxidize wine. Two most common are too much head space in the carboy, or too low of S02 levels in your wine. Be sure to mind these two things, and you may never experience oxidation.
Many people think when a wine has oxidized, you have to throw it out. Really, oxidation can be reduced, and in some cases eliminated by the use of powdered skim milk. It won’t win you any awards, but it can still become a good, drinkable wine again, reminiscent of the base you fermented. That is better than dumping it down a drain. Try this before you dump it.
- Calculate the amount of wine to be treated, in liters, and for each liter of wine measure out 0.5 gm of powdered skim milk into five (5) mL of cold water. Stir into a solution making sure all the skim milk is dissolved. NOTE: It is important that you use powdered skim milk, not de-creamed whole milk or malted milk.
- Now bring the S02 level of the wine up to the required amount with respect to the pH.
- Stir the wine vigorously and while it’s swirling, add the skim milk solution by pouring a single stream like what would come out of a sink faucet to make it enter the wine well below the surface. There may be a bit of foaming, but it will dissipate. Continue to stir the wine to ensure all the skim milk is well-distributed. It is important that the skim milk solution enters well below the surface. If you pour it on the surface, little, or nothing, will happen. I think the air is already having an effect on it. I have done this and botched ‘the pour’ before and it did nothing for the wine. Once the skim milk is fully distributed, brown curds will develop in the wine but will ultimately settle out.
- Replace the airlock and allow the wine to settle for 2-3 days. Meanwhile, prepare a fining agent for fining the wine if you want to try to polish the wine again. I have skipped this with good success.
- After 2-3 days, rack the wine off the oxidase curds into a clean carboy and stir in the fining agent (if you do one.) Allow this to settle for about 10 days, then rack the wine off the lees. Add an airlock. Filter. and bottle.
Let’s just try to avoid oxidation in the first place. Check your wine when it’s time, and make sure your sulfite levels are in line with the pH. When fermentation is complete, or when you know the wine is mostly degassed, ditch the airlock and plug that baby with something. I still have yet to find a decent stopper that I like, but I’m planning to be in stainless VC tanks soon. Have little headspace, or flood your headspace with an inert gas. I recommend Argon over CO2. We’re trying to degas our wine already and C02 being soluble, it can get back into the wine. Argon is better in winemaking.