WineMaker News Page

Updated August 30, 2022

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.

Chemical Analysis of Smoke Taint

wildfire smoke near Napa Valley
Photo courtesy of Frank Crowe

Phil Crews, a research professor of chemistry at UC-Santa Cruz and winery owner (Pelican Ranch Winery) teamed up with fellow researchers and chemists to form a nascent qualitative and quantitative way to measure smoke taint in potentially affected grapes. Using ultra high-performance liquid chromatography (UHPLC) and quantitative mass spectrometry and focusing on phenolic diglycosides that are undetectable by smell or taste until post-fermentation tastings, the group, led by Crews, has started to form a big picture of all the complex interactions that occur when wildfire smoke impacts post-veraison grapes. Their analysis focused on six biomarkers that the Australian Wine Research Institute had honed in on in their research into the same issue. Crews’ team found that two of the biomarkers were not indicative of potential smoke . . . hence the fact this analytical research is still a work in progress.

Microbiota’s Impact on Terroir

ripe merlot grapes rady for harvest
Photo courtesy of Pat Henderson

In the April-May 2021 issue we reported on how the concept of terroir was proven by a group of scientists studying several vineyards in the Mendoza region of Argentina. But the root cause of terroir is still yet to be determined. One camp argues that the microbiota found growing wild on the grapes plays a major role in determining a vineyard’s terroir. The other camp says the wild microbes have little to no impact and its expression has more to do with what happens underground with the interaction of the roots, soil, and the microbiota as well as the microclimate of the vineyard. Where do you stand on the issue?

New Products

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

August 19, 2022

Sonoma County Harvest Fair Amateur Wine Competition deadline for entries is 5 p.m. on Friday,
August 19. Wines can be received, either via mail or dropped off in-person, at the Sonoma County Fairgrounds. Entries are accepted starting August 1 and delivered wines are accepted the week of August 15–19. Judging takes place on September 10. For more visit

american wine society logo
October 7, 2022

Registration deadline for the American Wine Society (AWS) 2022 Amateur Wine Competition. Open to all amateur winemakers and includes still, fortified, and sparkling wines made from vinifera, native, and hybrid grapes. Also judged by certified judges will be wines and ciders made from fruit, vegetables, flowers, honey, and grasses. Pre-registration is required and the cost is $25 (AWS member) / $35 (non-member) per entry. For more information visit:

cellarmasters of los angeles logo
October 31, 2022

Judging for the 49th Annual U.S. Amateur Winemaking Competition will take place on November 12 & 13, 2022. Entries will be accepted from August 15 through October 31. Entries should be shipped to or dropped off at The Home Wine, Beer, and Cheesemaking Shop in Woodland Hills, California. Fees are $20 per entry. The U.S. Amateur is sponsored by the Cellarmasters of Los Angeles Home Winemaking Club. More information and registration forms can be found at

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.