Wine Flaw - Excessive Volatile Acidity

Ugh! My 2021 vintage has high volatile acidity (VA). It smells of pressed sugarcane juice and nail varnish. While I have made wine with high VA in the past, they were all within the threshold to be bottled and enjoyed. But the prospect for this vintage is dim. Hopefully, the addition of sulfites (sometimes referred to as SO2) will salvage some of it. 

Wait? Is sulfite the good guy now? What about VA? Let’s delve a little into the wine science. 

Nail varnish by Laura Chouette on Unsplash

What is VA?

VA is the measure of the volatile or gaseous acids in wine. The gaseous state of the acids is also the reason why VA can often be detected by smell. The aroma compounds that contribute to high VA in wine are primarily acetic acid (commonly known as vinegar) and secondarily ethyl acetate (associated with the smell of nail varnish). Oftentimes, the presence of VA is noticeable by the smell of nail varnish rather than that of vinegar. 

A certain amount of VA is acceptable and sometimes desirable to add to the character of a wine. Some sweet wines, such as Amarone della Valpolicella and Sauternes, and even dry ones, like Barolo, often accumulate a high level of VA. If you see the descriptor “lifted” in tasting notes or wine reviews, that’s what it means. However, when the level of VA results in an overpowering and off-putting aroma, it becomes unpleasant and can result in wine spoilage.

Acetic acid by CA Creative on Unsplash

VA is created by the activities of acetobacter. Acetobacter is a genus of acetic acid bacteria. It is widespread in nature and is responsible for creating vinegar, intentionally or otherwise. In winemaking, acetobacter can be found in bruised grapes, annoying fruit flies, winemaking equipment or anywhere in the cellar. Good sanitation practices, such as constant wiping down and cleaning with Star San, an acid-based sanitizer, is effective in limiting the presence of acetobacter.

SO2 versus VA

The reality is that it is nearly impossible to keep acetobacter out of the wine. The next layer of defense is to make the wine less conducive for bacterial activity. Acetobacter are aerobic organisms, which means they require oxygen to create havoc in the wine. Sulfite, an antioxidant, is often used to inhibit the microbial activity and growth. Yes, the much maligned sulfites are needed if you don’t want your wine to turn into vinegar.

Side note - How do natural wineries even make wine without adding sulfites? Maybe that is why natural wines often taste “interesting” and unpredictable!

Barrel tasting by Mauro Lima on Unsplash

Thankfully, modern science has crafted a formula to calculate the amount of sulfites needed for wine protection based on a number of parameters - such as pH and alcohol content. This hobby winemaker is just keeping up with it. 

Geek alert - As a rule of thumb, I have always targeted 50 ppm of FSO2 (parts per million of free sulfur dioxide) in the absence of a lab test. When sulfites are added to the wine, some will bind to the chemicals in the wine and some will dissipate. FSO2 refers to the remaining sulfur dioxide that is “free” or available to protect the wine. 

FSO2 need by pH level (Credits: enobytes.com)

As a hobby winemaker, I don’t perform multiple tests on my wine, unlike a commercial winery that would test throughout fermentation and aging. Instead, I tend to do a single broad spectrum test closer to bottling. Well, that did not work very well when the final test results indicated that the wine was not stable nor stabilizing.

My wine pH was >4.0, a first for me. Based on the chart above, I would have needed more than twice the regular SO2 dose to protect the wine. Even though I was dosing to achieve 50ppm FSO2, the test results showed that my FSO2 level was only at 4ppm. No wonder my wine is suffering from high VA. Recovery from high VA this late in the game is incredibly challenging. So lessons learned!

My Verdict: Rules of thumb are great until they don’t work. Learning from my own mistakes, albeit painful, sticks better. The good thing about winemaking is that if one vintage fails, you get to do it all over again the next year. You bet I’m going to do things differently, like doing focused tests on the wine and paying more attention to pH. I plan to kick VA in the butt for this next vintage. Wish me luck!

Sulfites Problems and The Magic Wand

Recently I had a few problems with sulfites in my wine. It is not what you think. In fact, it is probably the opposite of what you think. I forgot to add sulfites to my wine. I'll get into that in a minute. But first let's talk about more commonly known problems with sulfites - real and perceived.

Real Problem

Sulfites are naturally occurring compounds found in wine and other food sources such as peanuts, eggs, and tea. Because sulfites are also antioxidants, they are often added as preservatives to slow down browning or discoloration of food. 

In the 1970s as salad bars gained popularity in the United States, there was a dramatic uptick in the use of sulfites to keep the fruits and vegetables "fresh." With that came a rise in the cases of severe sulfite reactions. Sulfite sensitivity manifests in asthmatic symptoms such as wheezing and in rare cases anaphylactic reactions. Some people develop hives, swelling, or stomach pain. 

In 1986, the Food and Drug Administration (FDA) banned the use of sulfites in salad bars as a response to the increase in cases of sulfite allergy and sensitivity. It is estimated that about 1% of the population is sensitive to sulfites, and those with asthma are more susceptible.

Perceived Problem

Contrary to popular belief, headache is not a typical reaction to sulfites. But because many people suffer headaches from wine consumption, sulfites have become the easy target. In reality, wine-induced headaches are more likely due to dehydration from alcohol consumption or from the histamines and other compounds in wine. 

Wine wands

That said, the market wastes no time in capitalizing on the perceived problem of sulfites by offering a multitude of solutions, from sulfite-free wines to sulfite-removing wands, filters, and drops. While these may be effective in removing sulfites, one wonders if they eliminate wine-induced headaches or hangover since there is no scientific evidence that sulfites are the cause. There is however no accounting for the placebo effect.

Too Little Sulfites

The addition of sulfites during winemaking is necessary for the production of high-quality wine. Winemakers often pitch potassium metabisulfites into the wine post-fermentation to protect it from spoilage. When sulfites come into contact with the water in the wine, sulfur dioxide (SO2) is released. A portion of the SO2 will immediately bind with certain chemicals in the wine while the remainder will be in a free state (FSO2) to take on harmful microorganisms and to slow down premature aging of the wine.

Wine by Vladimir Fedotov on Unsplash

My first problem for my 2020 vintage is that I forgot my post-fermentation sulfites. While the science behind how much and when to add sulfites is complex and entails conducting multiple tests, a good rule of thumb for hobby winemakers is to pitch a certain amount every month to ensure adequate protection of the wine. And I did none of that this past vintage.

It was not till I ran a pre-bottling panel on my wine four months after fermentation that I found out that there were only 2 parts per million (ppm) of FSO2 in my wine. That is winemaker's talk for virtually zero protection for my wine from spoilage. 

Using the pandemic analogy, it is like going to a store without the protection of a mask or vaccination and hoping not to catch COVID. Thankfully, the wine was still tasting fine.

Too Much Sulfites

In my moment of panic, I googled the first website that gave me the target FSO2 level based on my wine pH. I did a quick calculation and pitched the sulfites as quickly as I could. Then I found a couple more websites that suggested target FSO2 levels that were significantly lower than the first website. One of the later websites had a target FSO2 level that was half of what I had pitched.

Great! Now a giant sulfite-removing magic wand doesn't sound so bad.

The truth is that it is hard to determine the right level of FSO2. Each wine's chemical makeup presents numerous variables that may bind with the sulfites, making it hard to determine how much FSO2 is left without running yet another test. Too much sulfites will inhibit the wine's ability to develop in complexity and give the wine a chemically metallic taste. Too little sulfites will increase the chance of spoilage. The winemaker treads lightly between the two.

Using the pandemic analogy again, it is like wearing five masks to the store which may protect you from COVID, but you may not be able to breathe.

Wine racking

Since I don't have a giant magic sulfite-removing wand, I decided my best recourse is to rack the wine despite mixed reviews with this approach. Put simply, wine racking is siphoning wine from one vessel to another, a process that introduces oxygen that will hopefully bind with excess sulfites. 

My Verdict: This is my fifth vintage. With every vintage, you learn something new that will help you improve your winemaking skills for the next vintage. There is no magic wand in that. I will let you know in 6 to 12 months how the vintage tastes. 

Wine Country and Wine Myths

Set in the gorgeous Napa Valley, Wine Country is a Netflix movie about six girlfriends who reunited to celebrate Rebecca's milestone birthday. With a strong cast of SNL powerhouses and Amy Poehler as the director, the movie surprisingly did not deliver consistently on its comedic moments.

Wine Country, the movie

However, getting past the slow start and some of the silly singing scenes, it is a warm and fun chick flick with hilarious stretches. The movie also highlights the strength of female friendships and the new possibilities of life even at 50.

Soppy sentiments aside, I want to share with you my favorite moments in the movie where some wine myths were parodied.

Myth of the Sophisticated Senses

The first winery that the girls went to was set on a hilltop, reminding me of an oasis paradise perched on the base of a Mayan pyramid. Filmed at one of my favorite Napa wineries, Artesa, the opulent outdoor tasting area was surrounded by lush greenery, overlooking an expansive pool. 

Breathtaking Artesa Winery

The tasting room pourer was eager to hear what the girls picked up from the wine. “There is no wrong answer,” he encouraged. He then proceeded to tell Rebecca that every note she picked up was wrong.

The truth is apart from some distinct exceptions (like a New Zealand Sauvignon Blanc), wine taste profile is incredibly subtle. While our taste perceptions are extremely personal, we are also very much influenced by our cognitive faculty. Wine connoisseurs in particular are trained to think certain ways about different grape varietals, and that influences how they taste. This is why blind tasting is so hard. Even Jancis Robinson and Robert Parker may pick up different notes in the same wine.

So if you feel like you lack sophisticated senses to pick up the "right" notes from a wine, just be like Rebecca and confidently proclaim, "Grape!"

Myth of the Sulfites

The movie was not shy about making fun of wineries that are overly zealous in their vinicultural and oenological practices. Morgan Jorng, a fictional winery that the girls visited, prides itself for being solar and organic. As such, they don't use pesticides or sulfates.


The pourer was probably referring to the very much maligned sulfites, often accused of causing headaches among wine drinkers. In fact, sulfites are natural occurring compounds found in all wines and are often added as an antioxidant and preservative to stabilize the wine. The true culprit of headaches is dehydration caused by alcohol. This can be easily remedied.

As a hobby winemaker and a chronic migraineur, I am skeptical when I see a wine that is advertised as being sulfite-free. I am even less trusting when I see gadgets in the market that claim to remove sulfites from wine so as to prevent headaches. Seriously, ditch the gadget, save your money, and drink more water.

Myth of the Sediment

I am thrilled that the movie introduced the topic of tartrates or wine diamonds. Tartrates, a natural byproduct of the wine making process, are often removed from white wine in commercial wineries through a process known as cold stabilization. This is because tartrates can look like ground glass and cause undue concerns to wine consumers. However, tartrates are really harmless and add to the flavor of the wine. Organic and minimalist wineries as well as hobby winemakers tend to skip cold stabilization. In fact, some would argue that the higher quality the wine, the more likely it is that you will see wine diamonds.

Wine diamonds often mistaken as ground glass

However, the movie left out the less glamorous contributor of wine sediment, which is often found in red wine. These are the leftovers from the fermentation process - yeast cells, grape seeds, stems, and skins. Known as the lees, these are often removed during secondary fermentation and aging through racking. It is a fine line how much lees contact you want in your wine. With experience, the right grapes or a particular style of wine, lees can contribute to a certain flavor profile that elevates the wine. However, as a hobby winemaker, I certainly err on the side of racking.

My Verdict: While it may not be the best Amy Poehler movie, Wine Country has some hilarious winery and girlfriend scenes. It is not that serious about wine so don't expect it to be SOMM 4 or A Year in Napa. However, it does bring forth some misconceptions about wine. More importantly, it inspires me to start planning for my big 5-0 wine adventure more than any other movie. Cheers!

First Vintage

Last October I posted about my first winemaking experience; well at least from crush through the primary fermentation and press. That was probably the most involved part of winemaking, when twice to thrice-daily punchdowns took place with constant measuring of temperature and Brix. That was when the juice was transformed from 'must' to wine as sugar got fermented into alcohol and carbon dioxide.

Secondary Fermentation

After the press, we moved into secondary fermentation of the wine in air-locked vessels. We used a 5-gallon glass carboy and three gallon jugs to use for top-up (I'll get into that later). This period was generally uneventful and less involved, but there were a few things that required attention.

Controlling the temperature. Malolactic (ML) bacteria, which was added to the juice the day before press, were quietly converting tart-tasting malic acids into fuller-bodied lactic acids. ML bacteria are sensitive to numerous factors (e.g. pH, SO2, and alcohol levels), but the one thing that worried me was my ability to keep the wine within the optimal temperature range (>70 degrees). The carboy and gallon jugs were wrapped in blankets, snugged in cardboard boxes, and gently warmed by a heating pad. My biggest fear was stuck fermentation since there were no easy tests to perform at home or measurements to track progress. I resorted mostly to prayers.

Lees left behind from racking

Racking, racking, racking. Even though most of the solid remains of the grapes and yeast (also known as pomace or marc) were removed during the press, there were still some remaining in the wine as it went through secondary fermentation. These are called the lees. Decomposing yeast in wine could cause off flavors. In order to remove the lees, we did multiple racking of the wine during secondary fermentation. Racking is the process of siphoning wine off of dead yeast into new containers.

We siphoned a total of four times; the first time was 24 hours after press, the next two were a week apart, and the final one was a month out.

Racking also has two other advantages:

• It clarifies the wine. You could literally see that the juice got clearer after each racking. In many cases, clear wine is just a matter of aesthetic. If the wine tastes good, cloudiness may not indicate flaws.
• When done correctly, racking can introduce controlled amount of oxygen into the wine. During the early part of secondary fermentation, oxygen has positive effects on unfinished wine by stabilizing the color and tannins. It allows the wine to mature gracefully and become more complex. In the later part of the secondary fermentation, caution is needed to minimize oxygen contact. If acetic bacteria is exposed to wine and oxygen, it will turn the juice into vinegar (acetic acid). 

It is important to note that you will lose wine during racking due to spills and as you avoid siphoning lees. The loss of wine during racking may increase the air space between your wine and the airlocks. You can top up the carboy with wine from the jugs or similar store-bought wine (preferably same varietal and AVA). Alternatively, you can add sterilized marbles into your containers to raise the wine level. I personally put some of my top-up wine into a sanitized plastic container, squeezed out as much air as possible, and capped it. It worked!

Final Testing

After more than three months of secondary fermentation, we performed the final testing of our wine to check on sugar, acidity, and ML fermentation. During the primary fermentation, which lasted less than two weeks, I was constantly monitoring and measuring progress. For the much longer secondary fermentation, I really had no idea what to expect. But I was pleasantly surprised by the outcome.

• Residual sugar was at 0.3%. This was probably the least of my concern since we pressed the wine at a really low Brix. Residual sugar over 0.6% is a concern for still red wine as it may cause re-fermentation in the bottle.

Measuring residual sugar in the wine

• pH was 3.78. This was slightly higher (or less acidic) since harvest, which was at 3.53. But it was still within the normal range.
• Titratable acidity (TA) was 7.3125. TA measures the amount of total acids and was higher than our reading during harvest, which was 7.125. It was a bit higher than I like, but not bad.
• ML fermentation appeared to have completed. While not the most accurate way to test the concentration of malic acid, the chromatography test is cost-effective. The solvent used for the chromatography is extremely toxic, and the test takes several hours. After putting dots of wine sample onto a piece of chromatography paper, it was left in a big glass jar with the solvent and the lid closed tight. 

With one exception, most of the wines appeared to have completed ML fermentation. Yellow patches indicated presence of acids. The top row of yellow revealed the presence of lactic acid, which is the goal of the ML fermentation. The bottom row of yellow revealed the presence of tartaric acid, which is also what we expected. Any yellow in the middle role revealed the presence of malic acid, which would indicate that ML fermentation has not completed. This would show that the wine has not stabilized and will need more time for ML fermentation to complete.

Chromatography test revealed that one of the wines still had malic acid

Bottling

Once the wines had passed all the tests, they were ready to be bottled. We got the bottles that we have saved up, cleaned, and sanitized. (We recycled bottles. If you buy new bottles, you can skip the above steps.) Sulfites were added to the wine just before bottling. Sulfites are a preservative and will keep the wine fresh. They are also anti-oxidants and will protect the wine from oxidation.

Adding sulfites to wine

Siphoning wine into bottles

Corking wine bottles

Finally, five months after harvest and crush, our first vintage was bottled and proudly named Abscession - a joke, as my husband was recovering from an abscess the day of the harvest. Special kudos go to my partner-in-wine, Alisa. That's her work on the label, making an access look classy. The wine will officially be released in the summer, so check back later.

Abscession 2016 Syrah

My Verdict: I am having so much fun learning about winemaking. It gave me a greater appreciation for wine. I don't think going commercial is my calling, but I'm planning for my next vintage already!