Growing, Processing and Selling Organic Grape Vinegar and Verjus

[Editor's Note: Verjus or verjuice definition from Oxford English Dictionary, 2nd ed. (1989): "...a highly acidic juice made by pressing unripe grapes, crab-apples or other sour fruit." It can be used in sauces and as a condiment.]

• Project Duration: 4/30/12 – 4/30/14
• Date of Report: 3/20/14

PROJECT BACKGROUND
Our family operates an 80 acre farm, located just northeast of the Black Hills of South Dakota. For the last eight years, we have maintained and improved the farm, allowing for vine maturation. Our organic vineyard now consists of over one thousand cold tolerant grape varietals, including Frontenac Gris, Marechal Foch, Frontenac, Valiant, Brianna, Kay Gray, La Crosse and La Crescent. The thirty-row vineyard is supported by a wire trellis system. It is irrigated by filtered well water on a drip irrigation system. During the grant period, we have planted eight additional apple trees and five plum trees for future organic vinegar product development.   We have mature tree wind breaks on the east and north sides of the vineyard. Since wind is a near-constant factor, an additional wind break of small trees was planted on the northwest side of the vineyard in 2013. The remaining acreage is utilized for hay production, pasture and waterfowl/wildlife habitat.

The previous owners of our property practiced organic and sustainable principles and we continued with the practice when we obtained the property eight years ago. We were USDA certified organic in 2012. The vineyard utilizes compost and natural fertilization from 100 free range chickens. The chickens have also virtually eliminated the need for additional pest control. Water usage is minimized through a drip irrigation system. Our farm attempts to create a friendly atmosphere for honey bees by planting flowers, alfalfa, and allowing clover to fully cycle throughout the summer. Weeds are removed by hand and large areas are controlled with mowing.

PROJECT DESCRIPTION

GOALS

1. Find a reasonable means to maintain organic practices and protect our grapes until fully ripened for a healthy/flavorful harvest.
2. Obtain proper processing equipment and storage vessels to convert the grapes into vinegar and verjus.
3. Determine best method to convert grape juice into most palatable vinegar and verjus products.
4. Run test products through established chefs for feedback.

PROCESS

1. A goal was to maintain organic practices with our vineyard, so we took the extra step of completing the USDA Organic Certification program to become a certified organic vineyard. The logic behind the extra effort was that the ultimate consumer would want the “green label” of assurance.   The vine netting was critical for the first step of our process. Prior to using the netting, we were losing a large amount of grapes to birds and deer. Without nets, we were forced to pick our grapes before they were fully ripe which diminished their value.  

2. We spent hundreds of hours researching equipment needs. We called numerous vineyards for recommendations and inquiries of used equipment for sale. Without much assistance, we resorted to traveling to St. Helena, CA and researched new/used vineyard equipment and sizing needs relative to our vineyard. The trip was at our own expense, but the result was obtaining the appropriate equipment.

3. After consulting experts/resources and reading numerous books/scientific journals on fermentation and vinegar conversion, we tested numerous significant variables regarding the conversion of grape juice to vinegar using the slow method. Some of the variables analyzed:

• Time of conversion as it relates to the temperature the liquid is maintained at.
• Adding commercial yeasts into the juice to make the end products more uniform.
• Testing the flavor profile result depending on the type of vessel it is converted in.
• The amount of time the vinegar is aged before tasted/consumed.

4. Beginning in September, 2013, we began offering our finished vinegars and verjus to established chefs throughout the country and in New Zealand. We described our products and asked for honest feedback to assist with our product development. Initially, we thought small viles of test vinegar would be sufficient for the taste testing. Later, we determined that the chefs needed more than a small taste and were provided 750 ml bottles of the various products so they could experiment with various culinary applications.

PEOPLE
Numerous culinary business people assisted with the project. Twelve culinary experts/chefs from New Zealand, Wyoming, and Colorado taste tested and used the different vinegar and verjus in their recipes. Without their feedback, the techniques for quality control would have been unclear.

Lawrence Diggs, AKA: The Vinegar Man, founder of the International Vinegar Museum, Roslyn, SD. Mr. Diggs spent two days at our vineyard, consulting on vinegar making technique development, marketing options, product tasting and proper sample testing techniques.  We continued with telephone calls and vinegar tastings.  We will continue seeking his expertise.

Rhoda Burrows with our Extension Service was extremely helpful and responsive to any question regarding vineyard management. She also hosted a vineyard workshop, uniting grape growers in the region.

RESULTS
We obtained USDA Organic Certification in 2012.   We have not yet seen an effect of whether the official certification is more important to the end consumer since the current customer chefs seem more concerned about the trust relationship already established with me through continuous interaction as their food supplier.   Through our communication, they understand the sustainability and organic nature of our products. If, in the future, our production reaches end consumers who are not familiar with us, then the USDA Organic Certification may become very important. 

Obtaining vineyard netting was a critical first step in the whole process. We did not receive trellis supports for the netting and as a result, the netting is just manually draped over the existing trellis. It is a time intensive process but the cost to add supports for the netting is cost prohibitive for us at this stage. As a result, we lose some of our harvest to exposed grapes and the netting is damaged because it is not properly secured.   It would be beneficial to have an improved method for the netting application and securing. For now, any netting is better than no netting and it will have to be sufficient!

Proper processing equipment was purchased only due to my extensive research.   Sales staff at vineyard supply stores were inclined to push us toward larger/faster/more expensive processing equipment than our smaller vineyard required.   We kept researching until we were comfortable with the limitations of each machine. Now we have large enough equipment to meet the requirements of an expanded bountiful harvest but did not “over-purchase”. We have used the processing equipment for two seasons and have had few mechanical problems. The constant “tweeking” to adjust for grape hydration, etc. has been an expected part of the process.

We tested numerous pertinent variables regarding the conversion of grape juice to vinegar using the slow method:

1. Time of conversion as it relates to the maintained temperature of the liquid. Results: We tried converting our juice into vinegar at lower temperatures than recommended by most experts and literature. Our thought was that if the conversion was slower than usual, then the flavor profile would possibly be deeper and more palatable than a conversion at a higher temperature. We learned that at a temperature below 76 degrees F, there is little activity and the resulting vinegar is not at a desired palatability. On our most successful batches, we placed our grape juice at a constant 80 degrees in a dark environment. The result was full and efficient grape juice conversion to vinegar at 3 to 4 months, depending on the sugar content of the grapes.

2. Adding commercial yeasts into the juice to force more uniformity into the end products.   Results: The grape juice with commercial yeast added converted well. However, we did not use added commercial yeast to many of our vessels and had no problem with conversion using the natural yeast on the grapes and in the air.

3. Testing flavor profiles based on the type of vessel it is converted in. Results: We tested glass vessels, stainless steel vessels, ceramic pottery vessels, oak barrels and toasted oak barrels. The taste testing results showed a slight preference for oak barrel aging but all other containers were not distinguishable in the final products.

4. The amount of time the vinegar is aged before consumption.   Results: Taste tests were conducted monthly throughout the process with undeniable results. The length of time the vinegar aged was directly related to the palatability and quality of the product. At least one year of aging after full conversion to vinegar seemed to show a marked improvement in smoothness, depth and quality.

Culinary feedback was a very important part of our grant because we believe that if we do not have a very palatable vinegar, then the end result is not worth the effort.   We received only positive feedback regarding the vinegars. Through the feedback, we determined the best way to go forward with future production techniques, as described above. Unfortunately, we did not receive adequate culinary feedback regarding the verjus. We assumed that the high end chefs would know how to incorporate the verjus into recipes. Instead, they did not take the time to experiment with the product. One chef actually had a bottle of verjus uncork itself and spew around the restaurant kitchen because he did not read the “keep refrigerated” label.   Even though we received substantial vinegar product feedback, it would have benefitted us to have provided recipes for the chefs to assist them in using the verjus.  

DISCUSSION
We learned how to convert grape juice into vinegar using the slow method. We learned the temperature sensitivity of acidobactors and the effect time and temperature have on the vinegar conversion and flavors. We learned that adding commercial yeast was not a critical step in our production. We learned that we can process our vinegar conversions in numerous types of vessels without affecting the flavor in a negative way. We learned that taste testers need to be provided with recipe suggestions if we want our product evaluated. We learned that manually netting our vines is partially effective but with a support system on the trellises, the netting/de-netting process would be much more cost efficient and time effective.

The biggest frustration was realizing how we could control quality but could not control the quantity of our harvest. In 2012, we were negatively impacted by the heat and drought. In 2013, our vineyard was hit by two catastrophic hail storms. As a result, our grape harvests were just large enough to test different conversion and vessel techniques.   We now have a limited amount of 2012 vintage vinegar to put on the market. Since the slow method of vinegar conversion is used, our 2013 harvest will not be ready as a vinegar product until late 2014. The advantage of having the SARE grant opportunity gave us the focus of a two year time period to test different techniques and document the results. Now we hope to utilize the knowledge and be inundated with a huge 2014 harvest!

Thus far, we have concluded that organic slow method vinegar production is a sustainable method, producing a delicious and healthy boutique vinegar. Our plan is to market the vinegars for approximately one year and then determine a price point of the end product. We hope the end result is a profitable venture. If demand exceeds supply, we will then decide whether purchasing other organic vineyard juice for our own conversion to vinegar is an attractive option.

OUTREACH
On-Site Programs: We hosted five groups of adults who attended separate 4-6 hour classes on vineyard care. Topics covered included the sustainability of organic farming/vineyards, weed management, and hands on pruning seminars. Approximately 100 adults attended. Two Spearfish, South Dakota elementary and middle school classes spent half a day at the vineyard as a field trip. They learned about raising chickens, and how to organically grow grape vines. Each student participated in vine trellising and pruning. The farm also hosted numerous personal tours of the vineyard regarding layout and pruning. Numerous chefs, from Arizona, Wyoming and New Zealand toured our vineyard and were exposed to our sustainable practices.

Off-Site Education: My wife assisted residential grape vine growers in Spearfish, South Dakota and Black Hawk, South Dakota regarding vine health, pruning information and techniques of simple juice conversion to vinegar. My wife was also a guest speaker at the Women In Agriculture Conference in Keystone, South Dakota. She spoke on sustainability of small farms and the value added strategy of “outside of the box” thinking with our goal to convert grape harvests into old style vinegars.

We created a website, threeheartfarm.com and saved numerous additional website addresses relating to vinegar production. We believe the website creation was premature, given the effort and cost required to maintain it. As an alternative, my wife is contemplating compiling and writing a manual/book on organic vinegar conversion.   We see value in a website for product dissemination and educational information once there is a product supply ample enough to meet the interest and demand of consumers.

We feel very fortunate to have processing equipment which allows us to convert our harvest. Without the equipment, we would have no means to take the steps toward a sustainable project. Last year, we assisted an aronia berry grower by juicing their berries with our equipment.   We hope to continue assisting other growers because we empathize with the new grower dilemma where they cannot invest the capital necessary to get their product into a marketable form.   We will offer the service through local fliers and through various state and organizational websites and emails.