Secondary Fermentation

How does this occur?

I had a bottle of 1997 Turley Zinfandel Hayne last week that was going through or had gone through secondary fermentation. I was talking to a retailer last night about this and he gave me multiple reasons, but I wanted to get a “professional” opinion.

Thanks for the help.

Is that better?

Malo-lactic bacteria (Oenococcus oeni, although several others can perform the job) eat up malic acid and poop out lactic acid. Since a lactic acid molecule has one less H+ atom than malic acid, this process drive up pH.
Is that what you wanted to know?

I’m guessing the wine was a little fizzy.
Would that be a result of the process?

Fizzy and some pretty obvious off aromas? Can you describe the condition of the wine?

Fizzy can mean residual primary/secondary fermentation or simply CO2.

The wine was purchased directly from Turley and stored properly. To be honest, this bottle was open about 13-14 bottles into an evening, but I could tell something wasn’t right. I remember it being slightly off on the nose, but nothing over the top, nothing like TCA or the like. Of course this wine is 17.1% on the label. There was a spritz on the tongue…just not something that I enjoyed.

17.1%? Yikes. ML bacteria really don’t like high alcohol levels, and 17.1% would be an extremely inhospitable environment. Not saying that they couldn’t survive that, but it is unlikely. If the wine is that high alcohol, it might have not gone completely dry, and if there was a high enough RS level and possibly was bottled unfiltered, it could have been a bit of residual primary ferm going on.

If this was the case…could this happen in just 1 bottle or would this be a across the board issue?

Wow, 17.1 huh? I should think it must have an RS of at least 1 or 1.5 or it would taste unbalanced and hot …

Reminding myself that the wine could actually be 18.6% by law, I’m thinking it’s potentially the vinous equivalent of one of these.

Actually, I think once you’re over 14 or 14.5, there is no slushie margin, you’re expected to report the actual alcohol. Besides, if someone’s flubbing for margins, they don’t choose a random number like 17.1.

Depending on the cause and how the wine was handled, it could be either. Take a primary referm for example, it could depend on whether it was filtered or not, or if the filtration was done carefully. If it was filtered but not done carefully, a few random yeast cells could have made their way through the filter pads/DE, whatever, and these cells could have made it into a few random bottles. If the wine was unfiltered and not racked carefully, there could have been all/many bottles affected, particularly wine that was at/near the bottom of the tank, which would be expected to have higher cell counts of whatever organism might be present. If the wine was blended into more than one tank, one tank could have been clean, while the other wasn’t. The list goes on. There could many variables present .

I stand corrected if that’s true, but it still sounds like a frag grenade waiting to happen.

The allowable label variance between actual alcohol and stated alcohol is 1% if over 14%, and 1.5% if under 14%.

As I recall you’re allowed 1% variance if you are over 14% and 1.5% if under. I generally believe more CA producers are as honest as possible than not on their labelling, but that doesn’t mean that I don’t think that those that are dishonest aren’t clever enough to pick a believable number instead of an even number.

What is the benefit of not having the exact alcohol on the label?

Not really a benefit, but the logistics of putting blends together balanced by the amount of time in advance needed to order labels means that what your best guess is about what your alcohol level will be may not correlate exactly with what you put in the bottle. Even if you think you have your final blend put together, you check the alcohol, and then order the labels, you may decide a week or two before bottling that you need to tweak the blend a bit more, so you add something else. That is going to change things.
Actually, I believe the variance was originally allowed because up until a few years ago, most wineries checked their alcohol levels with an ebuilliometer, and the results they give are notoriously inaccurate. Many wineries still use them (we do for in-house testing). Unfortunately, the accurate machines that use spectral methods such as FTIR or NIR are extremely expensive.

Linda, Mary, et al,

Are the new yeasts completely impervious to alcohol these days that they can restart in the bottle at 17 plus alcohol?

Heh, good point Thomas. Stranger things have happened, so who knows? Just from tasting Turleys I have always had the impression they run high in pH, so who knows perhaps some vigorous beastie in that bottle managed to survive? But that’s one of the reasons I asked for a description of the wine … also, perhaps the sensation of spritz could be from the burn of unbalanced acids or dead fruit that can no longer support the alc? The longer you age a zinfandel, the less unilateral consistency you’ll find. Other bottles of the same release might be outstanding? I will never know as I prefer older Ridge to old Turley.