WineMaker News Page

Updated November 1, 2022

Rethinking Vertical Shoot Position Trellis Systems

grapes ripening on a vertical shoot position trellis system
Photo by Ed Kwiek

A new study out from UC-Davis has shown that the popular vertical shoot position (VSP) trellis system is likely not the best trellising for warmer, sunnier sites like those found in California. The study looked at six different trellis systems, each at three different irrigation levels for two consecutive seasons. They tested a standard VSP trellis, two variations of the VSP system, a single high-wire cordon system, a high quadrilateral system, and Guyot-pruned VSP system. The irrigation levels were at 25%, 50%, and 100% of the crop’s evapotranspiration level. 

The researchers concluded that the single high-wire cordon system had higher yields and accumulated anthocyanins at harvest. They found that the VSP trellis had reduced anthocyanins and that the leaf arrangement with this style of trellising was overexposing the fruit to sun. Their conclusions were clear for those vineyards in a hot and sunny climate: It’s time to replace your VSP trellises. The irrigation aspect of the study was less surprising with higher irrigation leading to larger berry size and yields, but lower anthocyanin and flavonol levels.

More Great News For Grape Growers

diseased grapevines from esca
Diseased grapevines from esca. Photo courtesy of

In the August-September 2022 issue of WineMaker, we reported on a big potential breakthrough in the fight against glassy-winged sharpshooters, a scourge of California grape growers. In another breakthrough, scientists say they may have found the pathway and potential cure for grapevine trunk diseases (GTDs). GTDs are a fungal issue that has caused an estimated $1.5 billion in annual damage to vineyards according to a study done in 2012. Eutypa dieback and esca are two commonly known GTDs. The researchers found that a mix of reduced iron (Fe2+) and hydrogen peroxide combine in a complex interaction among several fungal species and are released into the wood. It is here that combination can prove deadly to grapevines because it releases free radicals. Free radicals are the reason we are told to take our antioxidants . . . they’re not good for any living creature.

The good news is that this combination of iron and hydrogen peroxide should be easily stopped by antioxidants and a common compound we know as chelating agents. So what is a chelating agent? It’s a chemical compound that reacts with metal ions to form a water-soluble, stable complex. They can be found in our food, in cleaning products, in medicines (such as cancer treatments), and water treatment systems, among other uses. So potentially by treating the wounds (growing fungi) on the grapevine trunk with a chelating agent and antioxidants, the reduced iron can be removed from the equation and hydrogen peroxide can be turned to water.

Hope For California Grape Growers

glassy winged sharpshooter
Photo courtesy of

For over two decades the glassy winged sharpshooter (GWSS) has been near the top of the list of pests that California grape growers fear most. A native to the southeastern part of the United States, it was brought to California in the 1990s and with it the ability to infect grape vines with Pierce’s Disease. While various species of sharpshooters existed in California prior to the arrival of the GWSS, none had the capacity to infect grape vines with Pierce’s Disease at even moderate levels.

Now, thanks to CRISPR technology, scientists at UC-Riverside are looking at ways to control this agricultural pest from California through genetic manipulation. In their initial research they looked at altering the eye color of the GWSS to see what effect it would have. They found it was passed down to three or more generations. The team was very excited by these results as it means changes could stick around for a while. The next step would be to look at altering the mouth of the GWSS so that it is more like the native sharpshooters, incapable of spreading Pierce’s Disease. As a bonus, this would mean that the use of chemical sprays for these insects can be shelved.

New Products

The World Of Natural Wine

cover image for The World of Natural Wine

While the world of natural wines can be fairly polarizing in some wine circles, there is no denying that it can produce some interesting wines. Made from grapes alone — organically farmed, fermented, aged, and bottled without additives — they’re a winemaker’s expression of linking wine directly to nature. Author Aaron Ayscough looks to navigate this movement in The World of Natural Wine. Meet the obsessive, often outspoken, winemakers; learn about the regions of France where natural wine culture first appeared and continues to flourish today; and explore natural wine in Spain, Italy, Georgia, and beyond.

Winexpert Winery Series

winexpert winery series box

A new line of kits from Winexpert is aimed at small- to medium-sized wineries. This unique series of craft winemaking kits allows you to make table wines in a variety of flavors. The Winery Series kits come in 3.7-gal. (14-L) concentrates and yield 12.2 gal. (46.2 L) of finished wine. They are releasing a California Chardonnay, California Moscato, Chilean Cabernet Sauvignon, and a Chilean Diablo Rojo. As with many of the kits, ease of use and dependability are key features. Sold in the U.S. exclusively through LD Carlson.

On-Line Alcohol Estimator

Govent alcohol estimator

The new GOvent from GOfermentor allows users to get a real-time estimate of the alcohol levels in their wine. By replacing your airlock with their alcohol estimator, which gauges the carbon dioxide gas released, you can graph and monitor the progress of your fermentation from anywhere using the optional Android/iOS app. The accuracy is +/– 0.25% ABV in closed fermenters up to 30 gallons (120 L) of wine, beer, mead, and other fermentations. There is an LCD display and WiFi internet connection is required for remote access.

RJS Craft Winemaking RQ Charisma Collection

rjs charisma collection

The new RQ series from RJS Craft Winemaking, the Charisma line, sources grapes from the Southern Hemisphere countries of Australia and South Africa. There are five options to choose from: A Chenin Blanc-Chardonnay-Viognier blend; a Grenache-Shiraz-Mourvèdre blend; a Semillon-Sauvignon Blanc blend; a Pinotage varietal; and a Merlot varietal.

Mosti Mondiale Vinifera AllGrape Edition

A new line of juice kits from Mosti Mondiale brings two elements of their current lineup into one package. Starting with a 10-L (2.6-gallon) concentrate, a 4-kg (8.8-lb.) AllGrape pack is included to provide the depth that comes with the grape pulp and skins. The grape packs are crushed, destemmed, and pasteurized. The Vinifera AllGrape Edition is made to produce 23 L (6 gal.) of finished wine in as little as six weeks. This aging time can be extended to achieve a more balanced wine. They will be starting with six different varietals, including Chilean Carmenere, South African Pinotage, and Australian Merlot to name a few.

Winexpert Limited Release Kits

A pair of limited release kits from Winexpert are being offered through their vendors; a Spanish Albariño and an Australian Mataro Shiraz blend. Both of these are part of their Reserve line of kits that inlcude 10 L (2.6 gal.) of concentrate to produce 23 L (6 gal.) of finished wine. The wines will be ready to drink in as little as 6 weeks, but the Australian blend will benefit from a more extended aging. Each kit comes with all the necessary ingredients and a set of instructions.

Upcoming Events

winemaker boot camp online logo
January 20, 2023

Backyard Grape Growing Online Workshop with Wes Hagen. Former professional vineyard manager and WineMaker’s longtime “Backyard Vines” columnist Wes Hagen will lead you online for four hours through all the steps a small-scale grape grower needs to know: Site selection, vine choice, planting, trellising, pruning, watering, pest control, harvest decisions, plus more strategies to successfully grow your own great wine grapes. All attendees will also receive a free download of Wes’ Guide to Growing Grapes and have access to the video recording.

WineMaker's Garagiste Con event logo
January 31, 2023

Early Bird Registration Deadline for Feb. 17, 2023 GaragisteCon Online. A full day of live online seminars and Q&A panels for small-scale wineries and aspiring wineries. All attendees will have access to video recordings of all sessions. There are three learning tracks: Business/Sales, Winery Operations, and Start-Ups as well as Q&A sessions with leading small winery industry suppliers. Get your questions answered live by industry experts. Also attendees get to interact with other small wineries and wineries-in-planning to compare notes. Register by January 31, 2023 to save $100.

2023 winemaker international amatuer wine competition logo
March 17, 2023

Entry deadline for the 2023 WineMaker International Amateur Wine Competition. Enter your wines, meads, and ciders and compete for gold, silver and bronze medals in 50 categories awarded by a panel of experienced wine judges. You can gain international recognition for your  skills and get valuable feedback on your wines from the competition’s judging panel.

winemaker confierence logo willamette valley
June 1–4, 2023

Save The Date for our 14th annual WineMaker Conference, which will be located in beautiful Eugene, Oregon. Join us in Oregon’s world-famous Willamette Valley wine region for four days of winemaking learning and fun. Don’t miss dozens of winemaking and grape growing workshops, seminars, and special events all geared for home winemakers.