Winemaking 101 – Episode 7 – When Things Go Wrong

Things sometimes go wrong in wine making, meaning the final product is not what was intended. Typical problems result from an undesired yeast or bacteria growing in the wine, or oxidation from too much exposure to air. For problems such as this, prevention is the key — once one of these problems is introduced, there’s not much that can be done about it.

I had a customer who purchased Niagara juice — she and her husband had good results as of late November of that year. She brought in a sample and it was pleasing. She was rightfully happy.

Fast forward to February — she brought in a sample that was brownish and smelled of oxidation. She revealed that they started drinking the wine from the carboy, leaving a large airspace, which produced oxidation. This is the equivalent of rust. Some how she missed the “bottling” part of the process.

My only solution was that they should bottle the wine immediately and drink it soon.

That’s a classic case of a preventable wine problem, but other problems can be harder to identify.

Off Taste

Last fall’s Malbec is an odd one. It started out fine and tasted great at pressing time. I have been doing this long enough that I can taste a very green wine and get an idea of how aging will affect it. The Malbec looked like a winner.

I used the pomace (grape solids after pressing) to produce a second run wine, which today is highly pleasing. But the Malbec (first run) developed an off taste, so something happened post-pressing.

I can’t identify the off taste. My younger son tastes sulfur, but there’s no hint of hydrogen sulfide (which has a distinctive odor).

One possibility is that my adjusting acid levels screwed something up. Being West Coast USA grapes, the acid levels were too low, so I added acid blend post-fermentation to increase the acid. Typically, acid is adjusted before fermentation, and while I added some acid, I didn’t add enough. The pH was too high and the wine tasted flabby.

We did experiments with small quantities to determine how much acid to add to each carboy. Obviously I measured wrong and the wine was far too acidic. So to correct that I added calcium carbonate. It’s possible that between the two, it produced harshness. In any case, I know I screwed up.

Ok, I have 4 cases of cooking wine. Ugh!

Fixing the Problem

I was going to make a batch of Cherry Melomel (Mead with Cherry) but got a better idea. We did a bench test with pure cherry juice, adding it to a sample of the Malbec. Sure enough, the cherry juice masked the harsh aftertaste.

So I racked one carboy into a primary fermenter (8 gallon food grade bucket) and started adding cherry juice, 1 quart at a time. Stir well and taste. We agreed that the addition of 5 quarts cherry to 5 gallons wine was right. The wine is sweet (3.3% residual sugar) but doesn’t taste it.

Then we did the same to the second carboy.

The final result is that I have 5 cases of Malbec-Cherry wine, slightly sweet and potentially likable by folks who enjoy off-dry red wines.

BTW — wine making requires taste testing on a regular basis. This is one of the prices winemakers pay to practice our art.  😉

The Future

I have no idea how well this will age — it depends on what caused the off flavor. If it’s acid/base related like I think it is, the wine will age fairly well, meaning it’s not suddenly going to go bad.

Right now the wine is green and I’d like to leave it for a year, but with 5 cases of it, I’ll start using it up. If any survives to make that 2 year mark, that’s cool. However, I have very good Merlot, Zinfandel, and second run Malbec/Merlot/Zinfandel that will be aging while we enjoy other wines.