At Fortress Vineyards, we focus on sustainable vineyard practices that, in combination with the unique high-altitude mountain vineyard terroir, provide the highest quality wine. All of our cultural practices are interrelated and work to improve the vineyard, the grapes, and ultimately the wine while at the same time, minimize the impact on the environment.
We continue to review research for new ideas and adopt relevant practices, adapting them to our particular situation. We do not undertake practices either to be the same as, or to be different from others, but only to keep striving for continued improvement.
We have found that our cultural practices not only contribute to producing exceptional fruit, but they are also environmentally sensitive conserving water resources, providing highly effective erosion control, fostering natural pest management and fertilizer and reducing fuel emissions. In addition, we endeavor to make socially responsible decisions about bottling, wine labels and promotions. We choose to use the DIAM cork which is not only a superior closure alternative but is also renewable, recyclable and biodegradable. Label paper, letterhead paper and collateral paper are all printed on recycled content.
Fortress Vineyards has used rice straw, a waste material from rice crops in nearby Sacramento Valley, since 2000. Rice straw is an inert material with excellent insulating value for energy efficiency and has been introduced recently to building construction. Our initial objective was to control and reduce irrigation water consumption. By placing rice straw under and around the vines, we experienced a 50% reduction in water consumption and found the straw to decay slowly with an effective 5 year life.
In addition to reducing water consumption, rice straw helps to maintain relatively constant moisture content and temperature of the soil beneath the straw. This eliminates typical large variations of being very wet and very dry between irrigation cycles. These two factors work to support the activity of soil invertebrates, particularly earthworms, and to accelerate soil decomposition increasing nutrient availability to improve soil fertility in a natural way.
Above the ground, rice straw encourages relatively large populations of generalist predators (spiders, beetles, flies, wasps, etc.) which exert natural control of pests such as vine moth, mites, weevils, vine scale, and mealy bugs. The straw provides natural weed control, eliminating the need to spray chemicals and it controls dust which, along with a clover crop down the rows, naturally addresses mite issues.
Most importantly, the use of rice straw mulch improves overall grape quality - our ultimate focus.
Clover is a nitrogen-generating plant and Sauvignon Blanc in particular needs a full measure of nitrogen to ensure wine flavors are enhanced. We selected a four-clover crop to mix with native grasses. The clover crop and rice straw both provide important erosion control in the rainy season as well as improved dust control during the growing season.
We have converted most of the vineyard from the Scott Henry trellising system to the Smart-Dyson system. This system uses a single spur-pruned cordon-trained vine and allows shoots to grow both up and down to split the canopy evenly. The Smart-Dyson system is perfect for the vineyard's location because it maximizes leaf exposure to the sun for photosynthesis while at the same time provides protection to the grapes from the sun. The system naturally spreads the grape bunches for uniform development and eliminates the need to pull leaves. It also accommodates the ever-present breeze, keeping the individual vine environment cooler and drier and minimizing humidity issues that are detrimental to the grapes. Because the trellis system spreads the canopy both up and down, the system also helps control vigor of the vine, again adding to overall quality.
From our own experience over the years, we have found that certain varietals, particularly red varietals, seem to develop better using a cordon-trained system.
Our objective is to harvest the “right” crop load with vine-to-vine uniformity. This is accomplished by determining the known average harvest weight per bunch and establishing the proper number of bunches needed produce the “right” crop load. Therefore, some vines need thinning while others may not. Immediately after bloom and fruit set, we count the bunches and thin all excess bunches on the vine. We do not thin vines with bunch counts at or below the target. The benefit of thinning early is that the vine is able to use energy to ripen fruit uniformly and evenly throughout the entire growing season.
The Biofungicides we use on the Fortress Vineyard are certified by the Organic Materials Review Institute (OMRI). We use a combination which primarily addresses powdery mildew, but also provides safety to beneficial insect populations. We have made the decision to use no sulfur products. While sulfur is regularly used by most growers, even organic growers, we are not convinced that when sulfur evaporates into the atmosphere and combines with water, that it doesn’t have the potential of adding acidity to rainfall. In a world of environmental unknowns and new questions being properly posed regarding environmental sustainability, we work hard to use certified biofungicide products and practices that minimize environmental risk.
At Fortress Vineyards, we have chosen to use the DIAM cork for our closure. DIAM is made from the “noble” component of natural cork treated with the patented Diamant process, a supercritical carbon dioxide process which basically eliminates TCA contamination of the wine and over 150 trace elements. Multiple tests verify that the DIAM cork is completely neutral to wine which means it will not alter the taste. It also maintains consistency in terms of permeability and decreases variability between bottles. It retains its shape well to prevent leakage and it is easily removable. In addition, the DIAM cork is a recyclable, renewable and biodegradable resource.
Fortress Vineyards began a new, night hand-harvest program for the 2007 harvest. This allows the grapes to be picked in a cool environment and remain fresh when delivered to the winery for an early morning crush. The picking begins at dusk and ends around one a.m. A custom-made, state of the art light system was developed for this project. It is mounted on a 50 foot light bar, and provides full light across 8 rows of vines. This allows two crews to hand pick grapes simultaneously. Because the vineyard is located at 2,000 - 2,400 feet elevation, the temperatures drop quickly and significantly, and the average nightly temperature is 60 degrees F. The grapes arrive at the winery in the morning, fresh and chilled by the mountain's natural refrigeration. This new system ensures delivery of top-quality wine grapes and allows the winery to begin crushing first thing in the morning. In addition, the crews like working in these cooler temperatures and have signed on in following years to do this type of harvest.