Sunday, February 26, 2017

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!