Bold Brianna: A strong and healthy grower

It was once called ES 7-4-76. At first glance, you would not have a clue as to what that meant. If you understand a little about grape breeders, given the vast numbers of seedlings they work with, everything gets a number long before a name is conjured up. In this case, the “ES” refers to Elmer Swenson (1913–2004), the grape breeder from Osceola, Wisconsin. Swenson was mostly a backyard breeder but was affiliated with the highly acclaimed viticulture program at the University of Minnesota, where cold-hardy grape varieties are developed for climates where it is difficult to grow Vitis vinifera. The University of Minnesota program has become increasingly important in the movement to promote “local” spreading all across the country. Cold-tolerant varieties have opened up new wine regions all across the northern states as well as Canada. Mr. Swenson had many numbered varieties, the one referred to as ES 7-4-76, moved into the big leagues to be known as Brianna.

Incidentally, the wine part came later. Brianna is a white grape, first selected as a table grape in 1989. It wasn’t used as a wine grape until 2001, so it is a relative newbie in the wine grape variety world. Swenson was focused on it as a table grape — it is reported that he did not drink alcohol! In regards to its name, as the story goes it is not named for Swenson’s wife or daughter. He did name one for his wife, Louise, at one point though. Brianna was actually named by Ed Swanson of Cuthills Vineyards in Pierce, Nebraska. Swanson likened it to a “strong and healthy grower,” so he first considered naming it Brian but that did not seem appropriate to him for a white wine. So the name Brianna was selected.

Viticulturally speaking, it is cold-hardy, but not entirely disease resistant. Black rot and Botrytis bunch rot are its short-term challenges, where crown gall can affect it in the long term. The clusters are small- to medium-sized with thick-skinned, medium- to large-sized berries. It is classified to grow in United States Department of Agriculture zones 4–8 so in addition to its cold hardiness, as low as -10 °F (-23 °C), it can also withstand blistering summer temperatures of up to 90 °F (32 °C).

When you look at the pedigrees of grapes, sometimes the past is very murky. Sometimes neither parent, or just one, is known. In this day and age, DNA analysis can be used to put together the pieces of the story. In the case of Brianna, it was not just Swenson who gets the credit, although he made the final two crosses; Jancis Robinson reports that there were “93 deliberate or natural crosses that led up to Brianna.” Swenson used material produced by his heroes, T.V. Munson (1843-1913) and Louis Suelter, a German immigrant to Minnesota, who in the 1870s, produced Beta (pronounced Bĕtt ah). Suelter eventually went on to produce Minnesota 78, of which Beta and Witt are the parents. Minnesota 78 is most likely 25% V. riparia, 37.5% V. labrusca, and 37.5% V. vinifera. Brianna eventually wound up with the following genetic mix: V. vinifera 34.57%, V. rupestris 6.25%, V. labrusca 31.64%, V. riparia 23.44%, V. aestivalis 2.83%, V. berlandiari 0.78%, and V. cinerea 0.49%. I am told that breeders sometimes muddy the waters on purpose to keep a little secrecy to their work, however in the case of Brianna, it does get complicated, but this is one of the most detailed pedigrees I have ever seen.

The V. labrusca contribution is the result of Concord being one of the parents of Witt, and also of Beta. With so much V. labrusca, there can be a propensity for the foxiness in the fruit. Therefore the fruit should be picked before full maturity. With Muscat in its recent parentage, it can be full of citrus and tropical fruit flavors, like pineapple and mango. Picking early also results in a lower alcohol wine. Swanson recommends picking when the pH levels are 3.2–3.4, but he prefers lower pH levels. Jacek Koziel conducted a study at Iowa State University in 2019 looking at the sequential harvest of Brianna and Frontenac Gris, which at the time comprised about one-third of the total grape growing area in Iowa. The purpose of the study was to measure, with very sophisticated equipment, grape aroma compounds and associate them with sensory analysis conducted by both professional and amateur tasters. The Brix range studied was 15.4 to 19.6, and a corresponding pH range of 3.09 to 3.45. In this study most of the desirable characteristics were found at lower Brix and pH and the study recommended that Brianna be “farmed for flavor” in addition to Brix, pH, and titratable acidity. Another testament to my long-standing belief that the best wines are made in the vineyard. If Brix is not sufficient to produce a dry or semi-sweet wine with a recommended alcohol by volume of 10–12%, then intervention with chaptalization was recommended as there are “few (other) intervention options” for enhancing the desired aromas in the vineyard through growing practices.

Wine balance not only involves pH and titratable acidity, of which the former lends to associate itself with stability and the latter with mouthfeel, but also alcohol balance. The alcohol balance has been sometimes referred to as the “sweet spot.” This will vary depending on the grape varietal and achieving that sweet spot can take on many forms. For high-Brix fruit, that might involve water additions prior to fermentation or de-alcoholization processes after fermentation. For Brianna, if the Brix falls short of that 10–12% target, the aforementioned study suggested chaptalization. Chaptalization is the process of adding sugar to juice or must to increase the potential alcohol. Potential alcohol can be estimated by multiplying the measured Brix by 0.55–0.60. The actual multiplier should be based on your own experience with the particular yeast used.

I generally use the higher conversion number, but regardless of which one you use it will get you in the ballpark as it is just an estimate anyway. The type of sugar you use, either sucrose or dextrose, can make a difference too. Dextrose is also known as glucose, or corn sugar, and is metabolized readily by the yeast. Sucrose, or cane sugar, is a dimer of glucose and fructose joined together by a glycosidic bond, therefore 50% glucose and 50% fructose. For the yeast to metabolize sucrose, the glycosidic bond must be broken. The glucose is readily consumed, but the fructose must be converted to glucose by an enzyme called isomerase. Some yeast have better expressions of isomerase than others, and thus are referred to as “fructophilic,” or fructose loving. I personally use corn sugar in a solution based on just how much I am trying to chaptalize. The more I need to sweeten, the more concentrated the solution. There are many chaptalization calculators on the internet, I use the one put out by Wine Business Monthly (https://www.winebusiness.com/tools/?go=winemaking.calc&sid=4).

Home winemakers are free to perform chaptalization on their juice but commercial wine producers need to remember that the laws across the country are different for commercial practice. Check your local regulatory agency for the rules in your area surrounding the chaptalization process.

Finally, as with any white wine where aromatic retention is desired, fermenting the wine on the cooler end of the selected yeast’s range is desirable. Good temperature control over your fermentation helps immensely with this goal in mind. Also, choosing a clean yeast strain like QA23 will allow those tropical pineapple and mango notes to shine. For more information on these concepts, check out the April-May 2021 issue’s “Advanced Winemaking” column on white wine aromatics.

Making wine with hybrids is fun, but sometimes a challenge. The growing seasons in these colder regions can be cut short by frost or torrential rains. I had a lot of experience making wine with the hybrids in the breeding programs I was involved with at UC-Davis. We really never had to worry about low sugars, rather getting the right flavor profile we wanted. Which lends itself to my often mentioned rule, a winemaker’s job is so much easier if the vineyard cooperates.

Brianna Recipe
(Yield 5 gallons/19 L)

Ingredients
100 lbs. (45 kg) Brianna fruit
Distilled water
10% potassium metabisulfite (KMBS) solution (Weigh 10 grams of KMBS, dissolve into about 75 mL of distilled water. When completely dissolved, make up to 100 mL total with distilled water.)
5 g Lallemand QA23 yeast (Premier Cuvee can also be used as a substitute)
5 g Fermaid K (or equivalent yeast nutrient)
5 g Diammonium phosphate (DAP)

Equipment needs
5-gallon (19-L) carboy
6-gallon (23-L) carboy
6-gallon (23-L) plastic bucket
Airlock/stopper
Racking hoses
Destemmer/crusher
Wine press
Equipment cleaning and sanitizing agents (Bio-Clean, Bio-San)
Inert gas (nitrogen, argon, or carbon dioxide)
Refrigerator (~45 °F/7 °C) to cold settle the juice. (Remove the shelves so that the bucket will fit.)
Ability to maintain a fermentation temperature of 55 °F (13 °C)
Thermometer capable of measuring between 40–110 °F (4–43 °C) in one degree increments
Pipettes with the ability to add in increments of 1 mL
Ability to test or have testing performed for sulfur dioxide

Step by step

1. Crush and press the grapes. Do not delay between crushing and pressing. Move the must directly to the press and press lightly to avoid extended contact with the skins and seeds.
2. Transfer the juice to a 6-gallon (23-L) bucket. During the transfer, add 16 mL of 10% KMBS solution (This addition is the equivalent of 40 mg/L or ppm SO₂). Move the juice to the refrigerator.
3. Let the juice settle at least overnight. Layer the headspace with inert gas and keep covered.
4. Measure the Brix. Ideal styles of this wine are around 11% alcohol, which is produced when the sugar is around 18 °Brix. You certainly do not want anything greater than 13% alcohol. If the Brix is low, add cane or corn sugar using a chaptalization calculator.
5. When sufficiently settled, rack the juice off of the solids into the 6-gallon (23-L) carboy. If you have a little extra juice, add 3 milliliters of your 10% SO₂ solution per gallon (3.8 L), protect the headspace from oxygen intrusion, and put it back in the refrigerator to be used to backsweeten after primary fermentation.
6. Prepare yeast. Heat about 50 mL distilled water to 108 °F (42 °C). Pitch the yeast when the suspension is 104 °F (40 °C). Sprinkle the yeast on the surface and gently mix so that no clumps exist. Let sit for 15 minutes undisturbed. Measure the temperature of the yeast suspension and the juice. You do not want to add the yeast to your cool juice if the temperature of the yeast and the must temperature difference exceeds 15 °F (8 °C). To avoid temperature shock, acclimate your yeast by taking about 10 mL of the juice and adding it to the yeast suspension. Wait 15 minutes and measure the temperature again. Do this until you are within the specified temperature range. Do not let the yeast sit in the original water suspension for longer than 20 minutes. When the yeast is ready, add it to the fermenter.
7. Add Fermaid K or yeast nutrient.
8. Initiate the fermentation at room temperature ~(65–68 °F/18–20 °C) and once fermentation is noticed, (~24 hours) move to a location where the temperature can be maintained at 55 °F (13 °C).
9. Two days after fermentation starts, dissolve the DAP in as little distilled water required to completely go into solution (usually ~20 mL). Add directly to the carboy.
10. Normally you would monitor the progress of the fermentation by measuring Brix. One of the biggest problems with making white wine at home is maintaining a clean fermentation. Entering the carboy to measure the sugar is a prime way to infect the fermentation with undesirable microbes. So at this point, the presence of noticeable fermentation is good enough. If your airlock becomes dirty by foaming over, remove it, then clean and replace it as quickly and cleanly as possible. Leave fermentation alone until bubbles in the airlock are about one bubble per minute, usually about two to three weeks.
11. The wine is considered dry or nearly dry when the Brix reaches -1.5 °Brix or less. Taste the wine — if it tastes dry, it probably is. If the wine is too acidic you have some options:
    a) Inoculate for malolactic fermentation using a lactic acid bacteria strain.
    b) Backsweeten the wine with the juice you set aside earlier. If you decide to backsweeten, make sure you clarify the juice and keep the temperature down near freezing. I then add 6 mL of fresh KMBS (10%) solution per gallon (3.8 L) of wine. This is equivalent to about an 80 ppm addition. Transfer the wine to the five-gallon (19-L) carboy and lower the temperature to near freezing.
    c) You could do both, but perform the process sequentially, the malolactic fermentation, then experiment with backsweetening. Do not add the sulfur dioxide until the very end.
12. After two weeks, test for pH and SO₂ and adjust as necessary to attain 0.8 ppm molecular SO₂. (There is a simple SO₂ calculator on the Web at www.winemakermag.com/guide/sulfite). Check the SO₂ in another two weeks, prior to the next racking and adjust while racking. HINT: Rack to another sanitized five-gallon (19-L) carboy, or your bucket. In the case of the latter, clean the original carboy and transfer the wine back to it. This is done at about 4–6 weeks after the first SO₂ addition. Once the free SO₂ is adjusted, maintain at the target level by monitoring every 3–4 weeks.
13. Consult winemakermag.com for tips on fining and filtration. If you did backsweeten the wine, sterile filter or dose with sorbate to prevent refermentation in the bottle.
14. At about three months you are ready to bottle. Be sure to maintain sanitary conditions while bottling. Once bottled, you’ll need to periodically check your work by opening a bottle to enjoy with friends.