MAKING RED WINE
January 6, 2020
By Frank Dominic Puzio ~ First Crush Winery, Cape Cod
At family gatherings long ago I remain with pleasant memories of joining my grandfather Dominic to his basement wine room. I recall the cool musty experience of the earthen floor, the old dark wooden barrels and the interesting smell of his wine room. In preparation for a family dinner, he would carefully pour his ruby-red homemade wine from one of the barrels into a glass pitcher. Inevitably he would then put a finger over his lips suggesting we share a secret. “Frankie, do you want to taste grandpa’s wine?” And with a predictable nod of approval he reached for a small glass, carefully opened the tap and poured small sample. We each shared a sip and exchanged smiles of approval. I now reflect that those memorable and endearing times with my grandfather and my observation of the joy he experienced sharing his homemade wine with his family would inspire me to attain that same experience all these years later. It pleases me that I am now the one making memories for my family and friends.
Over the years my personal understanding of the winemaking process has evolved greatly as I pursued a quest to learn more and also from what I experienced year after year. My goal has been to precisely document, and when possible, simplify the process so that I can confidently repeat the steps each year to achieve highly desirable results. For me the courting and romance in winemaking begins with the grape. With an established process, providing we have quality fruit to work with, we have an excellent chance to produce a very enjoyable product.
I often marvel at the mysterious transformation of the fruit into an enjoyable complex elixir. It is truly a gift of nature that has been initiated by people just like us for centuries. A combination of events and interactions of varied elements must all come together in perfect harmony. We must be aware that wine is a living-breathing organism, changing as it progresses through its life-cycle.
In winemaking, preparation is key: The procurement of all winemaking equipment, fermentation yeasts, nutrients, preservatives, etc., must be in the house by the end of summer in order to be ready when fresh grapes are available in late September / October. It begins with making certain you have the primary and secondary fermenter capacity vessels, as well as, your final oak aging capacity to accommodate the volume of grapes purchased. Known yield volumes from previous years determine these crucial estimates at each winemaking stage. Equipment is tested for functionality and cleaned appropriately in anticipation of all winemaking events to follow. In our case, since we are dealing with fruit that was shipped across the country, delays once the fruit arrives due to unexpected issues can jeopardize everything. Timely preparation and anticipation of each step are prudent! The winemaking events to follow will span over the next year before we have our final product to savor and enjoy.
It all begins with the fruit: Procuring quality fruit provides us the opportunity to produce quality wine. Since we now produce a large volume, of wine, my opportunities to go directly to the grower exist. The grapes we acquire arrive on our doorstep delivered by refrigerated trucks approximately four days after they are picked on the vine in California. Recently, we have been fortunate to obtain our grapes from a quality grower in the Suisun Valley region of California within one mile of the Napa County line. Despite the fact that our grapes were shipped across the country, I am always pleased to experience grapes that are fresh and irresistible to eat right out of the box. In 2012 and 2013 vintages, our cooperative crushed 20 tons of Cabernet Sauvignon, Merlot, Malbec, Zinfandel, and Petite Syrah. As a reference, a grower produces approximately three tons of grape per acre.
Crush Day: Once the grapes arrive on-site the physical work begins. The grapes have been off the vine long enough; it’s time to “stomp.” The fresh grapes are first crushed and separated from their stems using a motorized de-stemmer-crusher. The berries are not actually crushed, but rather simply broken and residual juice and berries are gently pumped into large open food-grade fermenters called “primary fermenters.” The amazing de-stemmer component of the machine separates 95% of the unwanted grape stems and discards them out of the end of the machine. The resultant mixture of juice and berries in red winemaking is called “the must.” Everyone wants to taste the juice at this point and it is the best tasting grape juice imaginable.
The Chemistry: In modern winemaking, chemistry plays a significant role in making quality wine. First, the sugar content is determined using a hydrometer. This provides an estimate of potential alcohol content post-fermentation, but also, if must sugar level is too low or too high in sugar content, the must is adjusted. A lengthy topic, however to date I have not had to make adjustments prior to fermentation. Temperature and pH are also measured at this time. pH and the modification of pH at subsequent stages are key in winemaking. Based on our initial pH, the must is protected from unwanted spoilage bacteria with a minimum addition of potassium meta-bi-sulfite, which we commonly refer to as sulfites. Acid titration experiments are performed to calculate the inherent acid level of the must. Napa vicinity grapes are typically deficient in acid content, specifically, the most common acid in wine grapes called tartaric acid. When you taste red wine, note the tart aspect of the taste. All too often red wine is too tart, too much acid, or flat, not enough acid. This acid adjustment of the crushed fruit prior to fermentation is one of the most important objectives and subjective decisions in winemaking. Based on these precise calculations, tartaric acid is added to each fermenter. A target pH is aimed for such that post-fermentation the resultant pH will fall into a perfect zone for quality red wine. It’s like trying to hit a moving target, such that you must aim in front of your target to ultimately hit your target. Adjustments can still be made post-fermentation, but as in culinary, getting the preparation correct in advance has a more beneficial effect on the outcome than attempting to modify the dinner after it’s been cooked!
Yeast Inoculation: In addition to sulfite protection the initial acid adjustment, must is also prepared in advance of fermentation with the addition of special wine yeast nutrients to enhance and ensure optimum fermentation. Once the must has attained the desired temperature, the bride is ready for the wedding. A yeast starter culture is prepared. Small containers (one for each fermenter) of juice, skins and special wine yeast are prepared. Once the activity is optimum, the containers are mixed into each primary fermenter. This begins fermentation, the wedding night, if I may indulge. During the fermentation cycle, the sugar content in the must will now be converted into alcohol and carbon dioxide and in approximately eight days we will actually have wine.
Primary Fermentation: In red wine, as opposed to white wine, fermentation takes place with the skins of the grape present promoting a desired extraction of color and beneficial tannins for structure. As fermentation activity advances, the creation of carbon dioxide gas pushes the grape skins to the top of the open fermentation containers forming what is called “the cap.” During each day of fermentation, the cap is physically pushed down, at least three times daily, to re-submerge and re-wet the grape skins. This physical and necessary process is called “punching down.” The height of fermentation activity is reached in 3-4 days and fermentation temperatures reach levels of 85-88 degrees F. When fermentation has completed, again in approximately eight days, the cap breaks down and you no longer have grapes and juice, you now have wine of approximately 14–14.5% alcohol.
The Press: We will now prepare for the second labor-intensive day, press day. The fermented wine is transferred into a wine press. The process compresses the skins such that what remains is liquid (wine) and fine particulates of grape skin particulates and dead yeast cells that the pressing process could not filter out. There has never been a winemaker or an assistant to the winemaker that could avoid sampling the new wine at this 7-10 day stage. It’s like tasting the progress of tomato sauce, or any chef’s creation, in advance of the meal. You guessed it; it tastes amazingly good for wine that was grape eight days ago. Generally a lot of, ”Wow, is that good!” But remember, we don’t want good wine, we want great wine!
Secondary Fermentation: After the press, a second sulfite addition is made according to the new pH, and if necessary, a small tartaric acid adjustment as well. Again, careful analysis and possible modification to achieve the desired pH range for this stage. Up until now, air contact has been necessary for fermentation to complete, but from now on oxygen contact is avoided. The pressed wine has been pumped into new fermenters called “secondary fermenters.” A special bacterium is introduced to initiate what is called, “malolactic fermentation.” This process softens the wine and results in what is described as a more pleasing lingering finish. The fermenters are then sealed until the end of malolactic fermentation which is confirmed by chromatography analysis approximately one month later.
Racking: During storage in the secondary fermenters, the fine particulate solids that remained in the wine after pressing have naturally settled by gravity to the bottom of the fermenters. In larger production commercial wineries the wine is most often mechanically filtered. I am convinced that forced filtration can strip some of the potential flavors from the wine. In our small production model, beneficial gravity filtering is more natural and is performed monthly until the wine has fully clarified. During this process, each closed fermenter is opened and the wine is pumped off temporarily, the chalky particulate matter called “lees” is removed, the fermenters are cleaned and wine is pumped back in and re-sealed. This clarification process is called “racking.” After approximately three clarification rackings over three months, the wine is pristine and ready for oak aging.
Oak Aging: The wine is then pumped from the secondary fermenters into barrels or special Flexitank vessels with oak inserts. We now age our wine for at least one year to mature and develop its flavors influenced by the oak and the wine’s natural maturing potential. During all of these stages in the winemaking process important chemistry analysis and adjustments are ongoing to enhance and hopefully ensure the winemaker’s desired outcome. Finally, after approximately 15 months the wine is ready for bottling and after a short period of recovery from what is called “bottle shock,” our wine is ready to be enjoyed. Only the first time you make wine are you waiting all this time to enjoy the fruits of your efforts. If this process is employed yearly you are drinking the wine from two years ago, and last year’s production is aging in oak while you are planning for this next year.
In Summary: The formula for success in making great wine requires special winemaking equipment, a proper work area, anticipation and timing of the processes, the ability to obtain quality fruit, attention to detail, cleanliness, utilization of basic chemistry principals, and finally, a controlled environment for aging and storage. I guess it sounds exhausting to read about it all at once; however crush the day and the press day, eight days later, are the two big labor-intensive and time-dependant days. All of the other stages can be planned for at convenient times and with much less physical effort. With all that said, the best parts of winemaking are the good times shared making and enjoying your wine with family and friends.
Salutē, Frank Puzio, Winemaker