A wine I have been making has a vinegar taste..is this normal?

I have a couple of red wines that I made from grape must…One of them a Barolo said it already contained yeast on the bucket so I used the enclosed yeast for my fermentation start Oct 17 This wine has finished its fermentation on a 6 gallon carboy and has been stabilized once after two rackings. Unlike the other wine this wine the Barolo has a slight vinegar taste. Is this taste normal in young red wines? The other wine an Amarone I used a packet of Paster Red as the yeast for fermentation on Oct 5th thou still a little cloudy tastes OK. Was I wrong to use the packaged yeast in the Barolo for frementaion of the must? Both wines are in my cellar with oak in them. I plan on racking the Amarone tomorrow because there is a band if sedimentation on the bottom of the glass carboy. I have been topping these wines off with a little C. savignon after racking to avoid oxidation. Any suggestions would be appreciated.

I don’t think vinegar is ever a normal or desirable taste in a wine, new or old. It is however one of the most common off flavors to worry about, because it is caused by an infection of acetic acid bacteria, which are commonly spread by fruit flies. The yeast you used had nothing to do with it, but rather a fruit fly somehow made its way into the fermentor.

You can minimize the damage if you act quickly. Acetic acid bacteria require warm temperatures and oxygen to thrive, and they can’t handle sulfites. They also tend to form as a film on the top of the wine. So here’s what you do:

Carefully rack the wine to a new carboy. The surface film (if there is one) will be pulled to and stick to the sides of the old carboy as it empties, seperating most of the bacteria from the wine. Also, don’t try to get all the wine transferred; leave a little more behind than you normally would.

Next, add sulfite. About 1 campden tablet per gallon of wine is a normal dosage, but for this (and only because you have an infection and the wine is fully fermented), use 1.5 tablets per gallon.

Top up the carboy with a similar, finished wine, leaving no more than 1 inch between the top of the wine and the bottom of the bung.

If possible, place in a cool location and leave it for a month. At the end of that time, taste it again to see if it has changed. If it has gotten worse, the batch is likely gone, and if it is unchanged, you’ve stopped the infection, but enough of the vinegar got mixed in that you will have to decide if you will still want to drink it.

Side note, if you had been planning to do a malolactic fermentation on this batch, forget it. The steps you need to take to combat the acetic acid bacteria will stop the malo too.

Hi Rebuiltcellars,

I will do what you said today. If I can save the wine, can I blend it with another wine if so what type. The other wines I have going is a Cab savignon and a Amarone or should back sweeten it to cover some of the vinegar taste? I believe NB has a backsweeting solution/conditioner.
Thank you for the reply.

Blending with another wine might improve things, but it might not. Worse case you could start with one good and one not-so-good wine, and end up with a larger volume of not-so-good wine. Before blending the batch, try blending small samples to see how it works out, then only blend the bulk after you find some mix you are happy with.

I have just finished racking the wines I think the Barolo did not appear to taste as bad (vinegar) after adding the first dose to Kmeta and Ksorbate. But after racking I gave it a good 2nd dose of Kmeta and some boiled toasted oak chips ( the oak flavor was a little low) . I will wait another month to see the results. The C savignon and Amarone are coming along OK. The amarone during racking had a surface film (slight opaque ) on the sides of the glass with a lot more sediment than the other wines. This wine I tried malolactic fermentation and tastes OK so far. Only the C savignon had the oak flavor I like so far. Now I have to wait another month to see the efforts of my labor. I will then add a small dose of kmeta and Ksorbate. I plan on adding ascorbic acid to the wines at bottling time per the wine recipe I have been using.
Thanks again.

Glad to hear the wine might be improving.

One important note: Ksorbate is only needed (or wanted) in wines that have residual sugar. It is best to leave it out of wines that are dry. And you absolutely don’t want to add it to wines that have undergone ML; it can cause an unpleasant geranium flavor to develop that is impossible to removed. Or so I’ve read - I’ve not tried this experiment myself.

Hi Rebuiltcellars,

Thank you for the reply,
I will make a note about the K sorbate in wines that have undergone MLF or are meant to be dry. So far my first efforts in wine making may be successful. My wife who prefers white wine has tasted the cab I am making and a mead gifted to me and likes them both. I have a mead started and I put a post in the mead section of the forum regarding a honey issue.