Category Archives: Winemaking

Anything having to do with wine production

Confessions of a Wine Yeast Wrangler

I have a confession to make publicly.  I am a Yeast Wrangler. In every fermentation, every harvest, I try to get inside the minds of these tiny fungi and discern what they want to eat, how they would like to be treated, and what temperature they would like their environment to be. They make the wine and winemakers try to keep them happy. They are like the ultimate prima donna who refuses to work unless everything in their environment is to their liking. If something is out of place, they immediately let you know by sending off Hydrogen Sulfide (H2S), which smells like rotten eggs, to voice their displeasure. If their needs are still not met they will shut down and die off resulting in a stuck fermentation. If one considers that winemaking is the physical act of converting sugar into alcohol and Carbon Dioxide (CO2), then I am a yeast wrangler and they are the winemakers.

In light of this, the selection of the strain of yeast or yeasts that will be conducting the fermentation is critical. Next to the date of harvest, it is one of the most impactful decisions a winemaker will make over the course of a wine’s life. Yeast can control alcohol levels, fruit emphasis, and style. They can also influence mouthfeel, acid levels, and Malolactic (ML) bacteria growth. Much of the later part of the life of a wine can be enhanced or hindered by the choice of yeast at the beginning. To that end, there are nearly endless choices available to a winemaker to choose for fermentation including “native”, selected or cultured strains, and a few options in between.

Going “Native”

Using the indigenous yeasts found in the vineyard and winery can be a double edged sword. On the positive side, they can add serious complexity and mouthfeel to a wine. They already exist in the winery therefore they don’t have to be purchased, which is helpful since the cultured strains can be pretty expensive. The downsides are they can be very difficult if the native strain is not a strong one, if the fruit is not perfect, if the nutrients they need are not carefully doled out, if the potential alcohol is too high, and if there are other yeast or bacteria strains in the fermentation which the dominant native strain does not get along with. These risks can be mitigated if one knows the reactions of their native strains well and knows their vineyards well also. There are now many examples on the market of excellent native fermentations including the Franciscan Cuvée Sauvage Napa Valley Chardonnay and all the selections of the delicious Bedrock Wine Company in Sonoma, CA. It should be pointed out here however that most “native” strains are the strain of yeast a winemaker may have purchased in a previous year that has still been hanging out in the winery or which dropped in from a cultured yeast fermentation from a neighboring tank.

Seeking Some Culture

Cultured yeasts are extremely widely used and many strains which we would consider cultured now were isolated as native strains from different places around the world. One of my personal favorite cultured Pinot Noir yeasts is RC212 which was isolated in Burgundy and named for the famed Romanée-Conti vineyard. Cultured yeasts offer some insurance against stuck fermentations due to high alcohol and have known characteristics such as nutrient needs, foaming potential, or H2S production so a winemaker is better able to keep them happy from the start of the fermentation to the finish. Beyond that, some cultured yeasts are bred for specific characteristics such as high Thiol production (think guava and grapefruit flavors of New Zealand Sauvignon Blanc), alcohol tolerance of 16% or higher, or high polysaccharide production which adds to mouthfeel and tannin perception. If you have enjoyed a glass of wine from a larger producer chances are good that it was produced using some strain of cultured yeast.

Best of Both Worlds

Of course, in winemaking as in life, things are not always black and white. Sometimes a winemaker wants the complexity and character of a native fermentation but the predictability of a cultured strain. This can be achieved through two main ways. The first option is to allow “native” yeasts to start the fermentation and then part way through add a smaller dose of a cultured strain to ensure that the fermentation will finish. The second option is to purchase a mixed strain such as Viniflora’s Melody which is a 60:20:20 blend of Saccharomyces cerevisiae, Kluyveromyces thermotolerans, and Torulaspora delbrueckii. These mixes theoretically mimic what would be found in a native fermentation except the strains are chosen that will complement each other. This ensures the different strains will not end up in the yeast version of Gladiator, with no single strain winning the fight to the death.

Regardless of the yeast option chosen it is critical that those strains remain happy and healthy throughout the fermentation and that is where the yeast wrangling part of a winemaker’s job comes into play. They have similar needs and, while some require more coaxing than others, both can adequately do the job if all those needs are met. It is harvest time now in the Northern hemisphere so for the next two months anyway you can find me roping fermentations into line and figuring out what each tank of yeast wants.

Originally Written for and Published on on 9/17/2015

Harvest 2015-Weeks 5&6: Recap

These past two weeks have been quite hot and dry for this area. Highs around 90 and very few cool nights. We just had rain over the weekend but I can’t speculate how much as of yet. Fall showed up yesterday bringing cloudy skies and blustery winds. The trees are starting to let the green fade away to be replaced by Crimson, orange and yellow.  The vinifera are ripening quickly spurred on by the heat. TAs are dropping more quickly than I remember as well. It makes me worried that the fruit that I thought would be ready in October will be ready while I am away in China. 

Speaking of China, I am supposed to leave this Thursday but am still waiting on flight confirmations. I have my visa now so if I can get flights I am set. 

This looks to be a great year for reds in the Finger Lakes. The Cabernet Franc we are picking for Constellation was one I was concerned about earlier in the year but after visiting the vineyard on Friday I am encouraged that I will be able to make some very nice wine. So much on the weather in the next 3-4 weeks as it always does this time of year. 

Cabernet Franc over Keuka on Friday. 

Meanwhile I am counting my blessings that we moved when we did. Napa and Lake counties are experiencing one of the worst fire seasons in recent memory. Thousands of people have been displaced by the Valley Fire and with 50,000 acres burned or burning as of last night it can only be described as devastating. I’m sure vineyards that I used to work with in the proximity of Middletown are probably gone. It is so sad and heartwrenching to see the photos. While Napa itself remains mostly unscathed, the smoke is hanging in the air which I know can be challenging for daily life, much less winemaking. My prayers go out to everyone affected and the Firefighters that are courageously  trying contain this monster fire. 

Crowd Funding a Vineyard? Randall Grahm’s Next Idea

I’ve seen quite a few things put up for crowd funding.  Start ups, charitable causes, and travel have all made their way through the sourcing sites that have made this method of raising capital famous. I even have a friend who designs games through crowd funding.  I’ve always wondered, for obvious reasons, if this type of funding would work for establishing a vineyard or building a winery.  Apparently, I wasn’t the only one pondering that.  Last week, on a day most suited to planting and sowing crops according to the Biodynamic planting calendar, Rhone Ranger and maverick winemaker Randall Grahm, announced he was trying just that on  I immediately reached out to Grahm to find out more about the project which sounded incredibly unique from the press release.  The idea is to establish a “living lab” on his 400 acre estate Popelouchum near San Juan Bautista on the Central Coast of CA.  The goal of the vineyard would be the breeding of 10,000 new grape varieties on site.  I caught up with Grahm late last week to get some more information on the project.

My first thought on a project this ambitious is how on earth do you decide which varieties get planted to be the parents of the 10,000 new varieties.  That, to my viticulturist’s eye, would be the most critical of choices which may decide the success or failure of such a project.  Grahm states they are “still working out the theoretical basis for the selection of ‘worthy parents’, but in the interim we’re looking at collecting data on which varieties (or clones thereof) seem to be particularly successful on our site – as far as vine health, flavor, drought tolerance, potential alcohol/acid balance and other criteria.”  He also mentioned working with Dr. Andy Walker of UC Davis to select from his recent breeding results some of which are 97% Vitis vinifera and may offer the best of all worlds from native disease resistance to European variety wine quality.  At the moment, it seems 100% natives (such as V. berlandiari) are being considered for rootstocks but not for further crossings with the chosen vinifera stocks.  Other scientists involved in the project are Dr. José Vouillamoz of Switzerland & Dr. Carole Meredith, a well known grape geneticist from UC Davis.

The initial report of the project mentioned that Grahm wanted donators to join him “on a journey of discovery to change the way we grow grapes, to change the way we think about vineyards, to perhaps discover an entirely new vinous expression.” I asked him what he envisioned those changes looking like.  His greatest wish is “complexity in wine arising from a lot of complexity in the genetic material constituting the vineyard itself.”  His “big leap of imagination is that perhaps a big set of maybe not so interesting grapes (in and of themselves) may yield a rather unique and special wine that is far more interesting and complex than a wine grown in the same field from a smaller set of “superior” varieties.”  This would be taking a selection massal theory to an entirely new level and then adding in dry-farming, biodynamics, and something called Bio-char, an activated carbon and compost mixture, to enhance the water holding capacity of the soils as well as the biological diversity of the microbial population in the soils.

Another aspect of the project that was interesting is a “major goal of the endeavor would be to establish a 501(c)3 status which would allow for crowd sharing with the community at large, the findings of the project over  the arc of a decade’s time.” I asked Grahm what did he hope to accomplish as a 501 c3 organization and what happens to the revenue from this project if he did succeed in finding a new grand cru site?  His answer was refreshingly frank and straightforward.

“Obviously, we hope to gain the sponsorship of some larger donors through the deductibility of the donation.  Since the entire intention of the project is to leave a legacy to California viticulture, the furnishing of the new germplasm as “open code,” as well as the sharing of research, as well as the extreme long-term nature of the project, makes this a natural for a 501c(3) organization.  While there will likely someday be some revenue from the sales of wine made from grapes grown on this site, it will certainly take many years to begin to recover the level of investment made.  At some point soon, we will work out a logical way to segregate the for-profit and not-for-profit aspects of the business.”

Finally, I wanted to get to the major question.  Why crowd funding?  Grahm had two main reasons for this; 1) He wanted to get the funding going to establish the site as a 501 c3 business and 2) to start building a community of like-minded people who would be “sincerely interested in this sort of project.  Not just wine-drinking connoisseurs, some of whom might be able to appreciate the audacity of the proposition, but others with a real interest in both sustainability.”  Don’t worry though.  Grahm is not expecting the crowd sourcing to foot the entire bill.  He says he has been and plans on continuing to contribute the “largest percentage of funds for this project” however he does anticipate that the percentage may shift if the non-profit status is granted.  To attract donations, Grahm has put together special packages for all of the donation levels ranging from signed posters, books, and gift baskets to having the new grape varieties named for you or your entire family!

At the time of writing his campaign was 12% funded with 25 days left to go.  At this point it seems off to a strong start!