Yeast - The True Winemaker

David Jammalo - April 2, 2024

True or False: Humans invented wine.  Of course it's a trick question.  I suppose the answer is “yes, but not really, well it depends…”.  Actually wine was probably more of a discovery than creation.  I thought I would focus on the workhorse of winemaking: the yeast.

What is Yeast?

Yeast is a single-celled fungus.  They are ubiquitous and airborne.  Most know that yeast is used to make leavened bread, beer, wine, and is the basis for distilled spirits.  What is interesting is that these specific yeasts are all one species, Saccharomyces cerevisiae (just one of ~1,500 yeast species).  

This species survives on two things: oxygen (aerobic) and carbohydrates (anaerobic).  When it lives in sugary fluids line crushed grapes or liquid malts, their environment becomes anaerobic.  They survive by fermentation, a process where they consume the glucose and produce ethanol and carbon dioxide (CO2).  The trapped CO2 gives beer its bubbly carbonation, gives rise to bubbles in bread dough, and sparkling wines.  Red and white table wines lose their bubbles during aging, like an opened can of soda that eventually goes flat.  And yes, bread dough can have traces of alcohol, but it is volatile and evaporates with baking.

Bread, Ale, Wine Yeast Differences

Since these three are the same species, what makes them different is their variety, biologically speaking.  I think of these like dog breeds.  A guard dog and a lap dog have very different personalities.  They look and act different, and each is good in their role, yet they are both canines.

Here is a breakdown of their general abilities:

• Bread yeast is best (or “selected” to be more accurate) for consuming grains and producing CO2, producing esters that add flavor.  Alcohol is not a consideration, like beer and wine.

• Beer yeast, like ale and lager yeast, have been selected and propagated for their positive traits they give during fermentation of wort (the malt solution) after the boiling process.  Lager yeasts can survive in near freezing temperatures, giving a lager-style beer cleaner flavors, but ale yeasts like ambient temperatures.  Both have lower tolerances to alcohol.

• Wine yeast, by contrast, are adapted to high sugar densities and alcohol levels (from their own alcohol production).  The environment can kill many wild yeasts, including bread and some beer yeast.  But wine yeast survive, although they begin to struggle as the alcohol rises.  By the end of fermentation, they themselves begin to die off, but because of human selection and domestication many get the job done and ferment to dryness where all fermentable sugars become depleted.

So most yeast strains today exist due to human selection, and even domestication from our own preferences.  

Varieties eventually became regionalized.  The best yeast in a cultural region have evolved into regional styles, like in Burgundy and Bordeaux France.  Each region has its yeast strains that created the regional flavor profile.  These evolved alongside indigenous and cultivated grapes in their regions, for example Burgundy grows Pinot Noir and Bordeaux grows Cabernet, and they have their respective isolated yeast variety.

Are bread, beer and wine yeasts interchangeable?  Not really.  Although bread yeast can make beer and wine, they usually don't work so well.  This is because each variety of yeast has been selected based on results, and tends to be selected and propagated.  Throughout history mankind has been experimenting and slowly migrating varieties of yeast to different regions of the world.  When a product becomes “better than the rest” in the region, people gravitate toward the best qualities, and those would be the predominant yeast strains.

Where Do They Originate?

Yeast is ubiquitous.  Wild strains of Saccharomyces cerevisiae yeast have been researched and live on host plants like the bark of oak trees and grape skins.  If you are picturing the Romans crushing grapes in oak vats, it seems inevitable that fermentation and wine is the most likely outcome.

The most reputable strains have become scientifically isolated from their cultural regions, incubated and packaged in liquid and dried forms (like Fleischmann’s yeast, who patented the drying process). Today professionals and hobbyists have access to the same world class yeast strains.  Many “new world” regions like California have their own yeast isolates available too, and some wineries have proprietary isolated strains.

The Two Winemakers: People and Yeast

Back to the topic.  I wanted to focus on the two winemakers: the yeast and the person.  The yeast do ALL the real work, that is, the production of wine from grapes.  So what is the role of the human?  I like to compare it to a good manager.   A good manager (in the context of this article) has some of these traits.  

Good managers can…

• Create a healthy environment

• Keep the workers happy

• Intervene when necessary

• Encourage growth

• Create the best conditions so that the workers do the best job

When the human winemaker achieves these conditions, the result is usually a great wine (Grape quality has more impact, but that is another topic.)  If they don’t, the yeast easily gets stressed and might put off all kinds of fowl aromas, some that persist even after the wine is bottled.

People Manage the Process

So the “human” winemaker manages the fermentation and intervenes when problems arise.  They can decide which yeast is best for the grape varietal.  They can ensure the yeast has enough nutrients to propagate their offspring.  The temperatures must be just right, like a nice warm bath - not too hot; not too cold.

Even varieties of wine yeast have different tolerances too.  For example some have higher tolerance to alcohol concentration, lower needs for nutrients, cold and hot temperature ranges.  

Nutrition is important.  Yeast divide and produce many generations and a huge biomass so there needs to be enough natural amino acids for cell growth, which mainly comes from the grapes.  Temperature needs to be managed too.  Fermentation is exothermic, and produces a lot of heat, and when the environment gets too hot, the yeast again get stressed.

Killer Yeast?  Really? 

Some yeast even have what is known as the killer factor.  This activity has been observed where a wine yeast strain is classified as sensitive, neutral, or active.  It is an enzyme that becomes active where they use it to kill and out-compete other natural resident microbes.  If a miniscule amount of yeast with an “active” killing factor enzyme coexists with billions of a “sensitive” variety, the “active” strain eventually dominates the fermentation.  

Think about it in this scenario: a winery just crushed 1,000 pounds of ultra premium Napa grapes (worth between $6,000-$10,000).  The winemaker has a goal they wish to achieve.  So they choose a yeast variety known for its red fruity traits, but it is known to be “sensitive”.  They add 100 grams.  After a day, the population grows to 100 billion cells per milliliter, or 370 trillion cells, and it starts vigorously fermenting away.  Another cellar assistant takes a measurement from another vat which contains a variety known to have an “active” killer factor, and accidentally crosses over to sample this one.  They just unintentionally added a few thousand cells.  This tiny fraction of cells in a week can completely dominate the fermentation, and change the wine's flavor profile.  

The result is probably still a great wine, but maybe not to the level for the winery’s expectations.  Accidental actions like these have reputation consequences, so a highly reputed winery could sell substandard batches on the wholesale market to other discount wine producers or bottlers, and probably sell it near cost.  Sometimes wineries really don’t know which yeast strain completed or interfered with a fermented wine.

Final Thoughts

Who makes the wine?  I would say that it's a partnership.  The yeast are the workhorses and the humans manage the process.  It's the human touch - the decisions and choices from the winemaker that wine lovers taste in the glass.  And as the saying goes, if humans didn't intervene in the winemaking process, the natural end result is vinegar.

Copyright (c) 2024 Jammalo Craft Wines, Inc.  All Rights Reserved.

Why Age Wine?

David Jammalo - September 2, 2024

Aging wines allows them to develop complexity and depth of flavor. This process of maturation occurs when flavor compounds react slowly over time to transform a wine from its youthful state into a more nuanced and enjoyable beverage.

Some reasons why wines are allowed to age:

• Softening of Tannins: Tannins, the dryness or “structure” found in many red wines become smoother and less harsh over time, making the wine more pleasant to drink.  Tannins from grape skins and seeds are important to red wines because they act as natural antioxidants and preserve the freshness of the wine during many years of maturation.

• Secondary Aromas Development: As a wine ages, it can develop unique flavors and aromas that are distinct from the primary fruit flavors found in young wines. These secondary and tertiary aromas are often described as notes of leather, tobacco, and spices that can add complexity and depth to a wine.  

• Increased Complexity: Aging can help a wine become more complex, with a wider range of flavors and aromas that complement each other.  

• Improved Balance: Over time, the acidity, sweetness, and tannin levels of a wine can become more integrated and balanced, creating a more harmonious drinking experience.

Not All Wines Benefit from Aging

Many white wines and some reds such as Pinot Noir or Gamay are often enjoyed young, while others, like Cabernet Sauvignon and Bordeaux, can improve significantly with age. The decision to age a wine depends on factors such as the grape variety, the winemaker's style, and the specific characteristics of the vintage year.  

Aging wine requires proper storage conditions to ensure that the wine develops optimally. Wines should be stored in a cool, dark place away from vibrations and large temperature fluctuations.  They are best stored between 50F - 60F.

There are Time Limits

Because they are beverages, all wines eventually begin to decline, I suppose like people.  After a few years, the tannins in reds will settle in the bottle and lose their protective qualities, a great reason to decant the bottle. Oxygen can slowly ingress through bottle corks to slowly oxidize the wine.  This is a main reason to keep wines on their side or up-side-down while they age so that the cork remains moist and taught.  Otherwise they can dry out and allow faster oxidation from the air.  This is not necessary for screw capped and synthetic closures, however.

One way to think about wine aging is that readiness to drink evolves in a way that mirrors a mathematical plot curve over time.

• Early Maturity: While pleasant to drink, the wine may be overtly fruity while tannins can be some­what coarse and acidity is at its most apparent.

• Peak Maturity: The wine is very expressive because the fruit, acid and tannin have integrated. All flavors combine seamlessly and the mouthfeel is well-balanced.

• Late Maturity: The wine has evolved to show more dried or cooked fruit and spice or earthy flavors. The color may turn more brick-red (or dark yellow for whites), and acidity and tannins are softer.

• Past Prime: The wine begins to develop characteristics that are undesirable and show age. Acidity and tannins are very soft to no longer present.

All wines age at different rates and the length of time it takes a wine to evolve depends on its natural components. Wines with high acidity and tannin tend to age better over a longer timeframe, but need that extra time to improve the balance.

A Deeper Dive to What is Really Happening?

A wine’s flavor and aroma have multiple contributors starting with the grapes themselves.  There are literally over one thousand compounds that are the building blocks to a potential wine. 

Then come the yeast, which through fermentation contribute body and fruity esters and polysaccharides (fermentation is the biological process of yeast converting grape juice to alcohol).  

Another aspect are many natural flavor compounds, some may be bound in complex molecular structures that are simply undetectable to humans, known as “precursors”.  But with enzymatic actions and time, these flavor precursors can become cleaved off and free to combine and react to make new flavors, or become volatile which improves the aromas.  This is one reason most quality wines are allowed to age several months, sometimes years in bulk vessels at the winery, before they are even bottled.  

The other main reason for bulk aging is to achieve natural stability. Small batch craft producers have time on their side to allow for proper aging without intervention, whereas many large producers add processing agents and additives to achieve shelf-stable wines that are quickly shipped to retailers.

Final Thoughts

Aging a couple years generally improves young wines, but as they mature beyond 3 years or so, they’ll tend to be at their peak.  Many ultra-premium wines can take a decade to realize their full potential.  But in my experience almost all wines are simply delicious after 1.5 years beyond the vintage date.  

If you have the patience and the space and the budget, buy two bottles and save one for a year.  You’ll enjoy both but the older one may have a surprise in store.  I still have a couple of inexpensive $14 bottles of Cabernet Sauvignon in the cellar of Kendall Jackson from 2000 and 2001.  I recently opened one with a friend who was there when we bought the case.  It was completely different from any wine I've tasted.  So give it a try, if you can wait that long.

References:https://www.ninerwine.com/aging-chart-blog

The Cabernet Sauvignon Grape

David Jammalo - January 21, 2024

Most people have heard of Cabernet Sauvignon wine.  Cabernet Sauvignon grapes are generally small with a high skin-to-pulp ratio, which lends lots of flavor, color, and tannin to wines.  It can produce big bold wines and is grown in many regions.

I thought I would start out by diving into the past to better understand why Cabernet Sauvignon has become highly recognized as the king of the wines, and discover why some wines have commanded astronomical prices across the world.

Where did the grape originate?

I found this answer to be fascinating when I first learned of it.  The short answer is that it originated sometime in the 1600’s in the region of Bordeaux, France by a natural random cross-pollination between two cultivated varieties known to the region.

Over time, many grapes morph and mutate resulting in other wine varieties, and evolve to our modern varieties such as Merlot, Pinot Noir, Chardonnay, etc.  Pinot Noir and Chardonnay are thought to have mutated from the same grape variety, and are genetically very closely related.  Both grow in the Burgundy region in France.

In Bordeaux during the 1600’s, the main varieties were the Cabernet Franc (a red grape), the Sauvignon, a white grape known for its wild “savage” like growth habit (today it is called Sauvignon Blanc), Merlot, and a few other famous blending grapes such as Malbec (meaning “bad nose”) and Petite Verdot.

How did the grape get its name?

Researchers at U.C. Davis used genetic typing in 1996(1) to finally prove that the Cabernet Sauvignon grape was a cross between a red and white grape, the Cabernet Franc and the Sauvignon Blanc.  It was thought to be a seedling of an accidental crossing and probably a grower noticed the shape and size seemed unique.  A grower would take vine cuttings from the mother plant and further propagate them throughout the Bordeaux region.  Interestingly, Cabernet Franc has also been attributed as the parent of Merlot, Carmenére, in addition to Cabernet Sauvignon.

Cabernet Sauvignon’s International Status

The wine’s popularity exploded in the United States after the now famous May 24, 1976 “Judgement of Paris”(2) Time Magazine article(3).  An English merchant in Paris, Steven Spurrier staged a small competition only to be judged by the French elite.  He only wanted to promote his non-French wines to Parisians, but unknowingly started a revolution.  

In the blind tasting, the French judges chose two winners for best red and white, both were California wines.  

Only one reporter decided to attend, George Taber of Time Magazine.  He wrote a tiny four-paragraph article(4) on June 7 describing the event and the results.  California wines including Cabernet Sauvignon and Chardonnay had reputations as commodity jug wines and finally became recognized for their quality, and the winners became highly sought out by the American public.  Other regions around the world slowly began getting their own accolades for wines and the quality improvements followed.  

And prices began to rise too.  In the 1960’s a bottle of Inglenook Cabernet Sauvignon was about $2 a bottle(5), and now can list for $100.  Many became cult wines that enthusiasts and collectors seek out.  These are small producers with high reputations that can sell a single bottle for $800 to $1,200, if you can find one.  Even in Bordeaux France, the original place of the Cabernet Sauvignon can fetch about $1,000 a bottle from one of the first-growth chateaux.  

Demand is still high, and science and research has given growers and winemakers better data to greatly improve quality.  There are cult-winemakers too.  A few of them seem to achieve consistent critics’ ratings from 95 to even 100 points (out of 100)!  When a winery can achieve 100 points, the price can jump 10X from $100 to $1,000.  This adds to the mystique of Cabernet Sauvignon, which is one reason it has become the largest planted wine grape in the world.

Final Thoughts on Grape Varieties

There are literally thousands of grape varieties, even tens-of-thousands.  Of course not all grapes make great wine, but many keep the birds quite happy.  

But there are possibly over a thousand varieties(6) that do make good wine and many are indigenous to the Caucasus and the Republic of Georgia, and throughout Italy.  We can probably only count less than fifty wine grape varieties even when we put our heads together.

(The Caucasus - Image By Bourrichon(7))

European countries like France and Italy have indigenous grape preservation(8) programs where scientists are scouring the lands to preserve varieties that are no longer found anywhere except sometimes in an individual’s backyard.

There are so many potential “great” wines from rare and unknown grapevines that are waiting to be discovered, even in our backyards - I do have a wild grapevine I don’t recognize.  When we try a wine that we don’t recognize, we expand our pallets and appreciation to keep the next possible future “king-of-the-grape” or its offspring from going extinct.

References

1.  DNA Fingerprinting Reveals Parentage of Classic Wine Grape by Pat Bailey April 25, 1997, U.C Davis, https://www.ucdavis.edu/news/dna-fingerprinting-reveals-parentage-classic-wine-grape

2.  https://en.wikipedia.org/wiki/Judgment_of_Paris_(wine)

3.  https://time.com/4342433/judgment-of-paris-time-magazine-anniversary/

4.  https://time.com/vault/issue/1976-06-07/page/78/

5. https://www.winespectator.com/articles/the-glory-that-was-inglenook-1057

6. https://www.wineenthusiast.com/varietals/

7. Maps - By Bourrichon - fr:Bourrichon with English translations, additions, and corrections by Ketone16 (partly following Yuri Koryakov) - Own work ;Topographic data from the NASA Shuttle Radar Topography Mission (SRTM3 v.2) (public domain) edited with 3DEM, reprojected in UTM with GDAL (GDAL), and vectorized with Inkscape ; UTM projection ; WGS84 datum ; shaded relief (composite image of N-W, W and N lightning positions) ;Reference used for the additional data :* Rivers, cities, railroads, routes, bathymetry : Demis add-on for World Wind (see the approval e-mail and the Demis forum) ;* Borders and coast : World data bank II ;Approximate scale of topographic data : 1:1,463,000 ;Note : The shaded relief is a raster image embedded in the SVG file., CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=50309413

8.  https://www.winespectator.com/articles/saving-the-wine-worlds-unheralded-grapes-48701

Wine Bottle Storage: Upright or Sideways

David Jammalo - July 9, 2024

I thought this was broadly understood, but after a conversation with my work colleagues, I learned that many people were not aware of why some wines are aged on their sides.

The reason is to keep the cork wet.  But this rule only applies to wines with a natural cork, and only if you plan to hold it longer than 6 months.  If both these are true, then it is best to store the wine sideways and keep the cork in contact with the wine.  

Wines that are meant for early consumption usually have synthetic closures made of rubber, plastic, or screw caps.  These can be stored upright.

Why is it best to keep natural cork wet?  Keeping the cork in contact with the wine reduces the risk of oxidation.  Oxidation is the biggest threat to wine, because quality deteriorates with excessive oxidation and robbing a wine of its youthful character.  When wines are stored upright, the natural cork tends to dry out and get rigid.  They can lose their elasticity and air can infiltrate the top of the wine at a faster rate.  

Most wines, even organic natural wines, have small levels of sulfites.  These act as antioxidant agents, which fends off oxidation while the wine is young.  Sulfites, or SO2, is a dissolved gas and can easily diffuse through the dried out cork.  The wine loses its protection and white wines can start to turn dark golden-brown, and red wines can turn a brick-orange color.

When in doubt, store it sideways.  Make a wine rack or buy one that holds the wine sideways so they are always protected. (DIY wine rack using tin cans https://youtu.be/qlJ6cw9_Q1w?si=9JmsN-oGGq0SRWA0 )

By David Jammalo - July 22, 2023

The use of sulfites has been a contentious subject for some people.  However many facts are misunderstood.

What are sulfites and why are they in wine?  

What are the facts about the health effects? 

Do European wines have sulfites?

First, as a disclaimer, I am a winemaker and not a qualified physician.  This information does not constitute health advice.  I am qualified as an educated winemaker and not an expert in chemistry or health.  So take it as just a way of expanding knowledge about the industry.  But I give factual references so the information is scientifically verified.

What are sulfites and why are they in wine?

I’ll start with the first question.  Sulfites (or Sulphites) are actually various forms of sulfur dioxide (SO2).  When wine yeasts (s. cerevisiae) ferment grapes into wine, they expel tiny amounts of SO2 as part of their metabolism(1).  So young wines almost always have SO2 with levels typically from less than 10 parts per million (ppm) to more than 100, but typically it is less than 30 ppm.  

How much is a ppm?  To visualize 1 part-per-million, it is about 1 inch in 16 miles, 1 minute in 2 years, or 2.5 liters in an Olympic swimming pool. 

Wine yeast have evolved through the millennia to out-compete and dominate the other native microbes by excreting alcohol and SO2.  SO2 acts as an antimicrobial agent, however the yeast are not inhibited by these small amounts they generate.

Two Benefits of Sulfites in Winemaking

As an antimicrobial, SO2 can be added in the winemaking process to inhibit spoilage microbes and encourage the beneficial microbes: those that make our delicious wines.  Many wineries have modern practices that minimize the need for excessive SO2 additions.  These additions can range from none (in some organic wine), or up to the legal limit of 350 ppm in the United States(2).  But most industry members only need to add 25-35 ppm SO2 in order to maintain the quality.

One tool winemakers use to reduce the use of SO2 is to maintain a lower pH so the wine becomes self-preserving without excess SO2.  SO2 becomes exponentially more effective in higher acid wines like Sauvignon Blanc or Riesling (wines with a low pH)(3).  Another tool is filtration at the time of bottling so that the vast majority of microbes are removed before it is sold.

SO2 is also an antioxidant.  It sequesters compounds that prematurely age wines in a negative way.  Small amounts of SO2 added at bottling, even about 10 ppm, can add years to a wine's aging potential.

European Wines Don’t Have Sulfites: Myth

First of all I want to dispel a common myth that European wines have no sulfites. “Many” European wineries do add sulfites.  Not all, but many do. It is a common misinterpretation of the labels from Europe.  There is simply no European regulation that requires them to state “contains sulfites” on the label.   I am speaking of wines that are only sold IN Europe, not imported into the U.S.  

I’ve personally heard people tell me they don’t get headaches from Italian wine because they don’t add sulfites. There is a lot of confusion on this topic.

Why do most domestic wine labels have the statement “CONTAINS SULFITES”, whereas wines in Europe do not?  (Imported wines sold in the U.S. do indeed have the statement on the label).  This statement is a Federal TTB regulation for consumer protection.  But there is a historical reason for it in the U.S.:  The Salad Bar incident.  

Fast food restaurants back in the 1980’s were adding extremely high amounts of SO2 to keep the fresh vegetables from browning, estimated to be about 10,000 ppm.  That is like taking 200 aspirin tablets per dose.  It was done by inexperienced staff without proper training or instruction.  Over time 13 people died from excessive SO2 in these cases (see “Sulfites in the Salad Bar”(4)).

Laws were passed to stop the practice altogether in restaurants, but remained as a warning statement on wine bottles, even though the wine legal limits are exponentially less.  The United States is the only country in the world that requires this warning statement.

Organic Wines: Wineries that choose to add no SO2, like organic wine, can claim statements like “No Sulfites Detected” on the label among a few others(3).

Health Effects & Allergies

A true sulfite allergy is also commonly misunderstood.  When some wine drinkers complain of sulfite headaches, they most probably have a sensitivity to higher concentrations of SO2, or other compounds naturally occurring in grape wine, like histamines(5).

Let's discuss allergies first.  There are very few people that have allergies to sulfites.  Those who do lack the digestive enzyme sulfite oxidase and therefore cannot metabolize sulfites.  Our own bodies produce about 1000 ppm of SO2 every day as a part of metabolism.  Many people born with a true sulfite allergy have chronic issues or never even survive beyond the first year of life, because our own bodies produce much higher quantities than what is legally allowed in wine(5).

That brings us to sensitivity.  Some people are much more sensitive to white wines than reds, and some are vice versa.  So what is going on?  People that are sensitive to sulfites include people who suffer from asthma.  This is a very real and valid concern for those who consume wine containing higher levels of SO2.  It can actually be dangerous for those asthmatics in rare cases.  

For the majority of wine drinkers and wines, SO2 is barely or completely undetectable.  But is this really true?  It depends on the wine and the winemaker.  

In general red wines have and use less SO2 for long term stability when the tannins are higher (think Napa Valley Cabernet).  Tannin from the seeds and skins provide natural protection against oxidation (and aging).  White wines don’t have tannin, so sometimes winemakers add a bit more SO2 for protection against aging (think antioxidant).  But then again, some bright acidic white wines need a lot less SO2 for the same protection.  So it depends on many factors.

Final Thoughts on Sulfites

Sulfites in wine are a natural byproduct from fermentation.  It generally exists in minute quantities and, according to the FDA, is generally regarded as safe(6).  It has been used since the Roman Empire as a preservative that allowed wines to last and age while avoiding spoilage.  

The natural end state of grape wine is vinegar, unless humans intervene and provide methods of protection.  For thousands of years and with modern winemaking techniques, SO2 is still the best compound of choice that helps winemakers keep oxidation away from wine, and judicious use of minute quantities helps preserve the quality. Some winemakers claim it enhances freshness and fruitiness.

A final tip: sulfites are volatile.  If your wine is younger than about 5 years, open it and pour it while you splash.  Swirl it - not just to look fancy - there’s a purpose for the swirl.  Decant it and let it breathe a bit by exposing it to the air.  All these actions help dissipate the sulfites and aeration improves the aromas.

When we put these myths and facts in perspective when discussing sulfites as it relates to wine, we become better informed about the beverage we love.   

References:

(1) Rankine, B.C. and K.F. Pocock. 1969. Influence of yeast strain on binding of SO2 in wine and on its formation during fermentation. J. Sci. Food and Agric. 20. pp. 104-109. Eschenbruch, R. 1974. Sulfite and sulfide formation during winemaking - a review. Am. J. Enol. and Vitic. 25:3, pp. 157-161.

(2) TTB Federal Code of Regulations: Title 27 CFR 4.22(b)(1)

https://www.ecfr.gov/current/title-27/part-4/section-4.22#p-4.22(b)(1)

(3) TTB Federal Code of Regulations

 https://www.ttb.gov/labeling-wine/wine-labeling-declaration-of-sulfites

(4) The Washington Post

 https://www.washingtonpost.com/archive/lifestyle/wellness/1985/04/03/sulfites-in-the-salad-bar/4cf7eb5b-955a-4312-869c-ec145af4be74/

(5) The Regents of the University of California 2007,Lesson 7: Fermentation & Aging: Sulfur Dioxide (SO2) Topic 7.2: Health and SO2 Sensitivity

(6) Select Committee on GRAS Substances (SCOGS) Opinion: Potassium metabisulfite, sodium bisulfite, sodium metabisulfite, sodium sulfite, sulfur dioxide

http://wayback.archive-it.org/7993/20171031061022/https://www.fda.gov/Food/IngredientsPackagingLabeling/GRAS/SCOGS/ucm261009.htm

Do you know what a wine label must contain, and what are the basic requirements for wine producers?  Well even the most experienced producers don't always get it right.  That is why the federal government’s Department of the Treasury oversees and approves labels on most alcoholic beverages, including table wines.  The governing bureau is the Alcohol and Tobacco Tax and Trade Bureau, or TTB.  

So what is table wine?  There was a time when the term “table wine” was thought to mean jug wine or inexpensive wine.  But table wine is a classification used by government agencies to set and collect alcohol excise tax.  Therefore table wine is any wine between 7 and 16 percent alcohol.   This means a jug wine for $5 and a cult wine for $250 are both table wine, if the alcohol is between 7-16%.

Some wines that are not intended to be sold interstate can file for a label exemption, but they must have a statement stating “for sale in MA only” or the state where the wine was produced. Every wine producer must submit an application for label approval or exemption application to the TTB before it can be sold to the consumer.

The minimum information for a wine label

Proprietors of wine premises must label each bottle or other container of beverage wine prior to removal for consumption or sale with the following information:

• Name and address of the wine premises where bottled or packed;
  
  

• Brand name (if different from the name of the premises where bottled and packed);
  
  

• Alcohol content, as percent by volume or in a format described in 27 CFR 4.36 and 4.38(b)(3);
  
  

• Net contents of the container; and
  
  

• Designation of the kind of wine: The designation must include enough information (when viewed with the alcohol content statement) to identify the tax class of the wine and to adequately disclose the nature and composition of the wine. The wine must be identified by the term “wine” (or a word that signifies a type of wine, such as “cider,” “perry,” or “mead,” as applicable). If the wine contains more than 0.392 gram of carbon dioxide per 100 milliliters, the word “sparkling” or “carbonated,” as applicable, must be included in the designation.

The rules and requirements are complex.  If you are interested for more information, see the TTB site: https://www.ttb.gov/wine/7percentormore

A typical bottle of wine is 750 ml which contains about 25 fluid ounces.  The accepted standard glass of wine will have about 5 oz., so there are usually 5 servings or glasses per bottle.

Some people prefer a bit more and tend to pour a glass with 6 oz., which makes the servings per bottle just four, but this is not the accepted standard that is used, especially when estimating one's consumption of alcohol per hour.

When planning a dinner party or holiday gathering, the question is how many bottles does one need?  One can expect to serve about two glasses of wine per person, which is best enjoyed with a meal.  (Alcohol is consumed into the blood stream 40% slower when consumer with food.)  So a good estimate for entertaining guests is to have 1 bottle per couple.

Rule #1: Keep everything clean and sanitary.

Rule #2: There are no recipes.

(These are my rule lessons from classes and empirical experience, which may differ between winemakers.)

The winemaking process can be as simple or as complicated as a winemaker chooses.  Every year's grape vintage can be as different as the weather.   It all depends on how the winemaker chooses to proceed and what style they hope to achieve. 

As my professor coined it, "winemaking is a sum of a thousand different decisions"(1) and no two wines can ever be the same.  I'll try to boil it down to the minimal general process steps.

Red Wine Process

1. Red grapes are crushed,  stems removed (now called "must").

2. The "must" is moved to a vessel, like a tank, tub or pail.

3. Optional temperature, sugar, and acidity adjustments can be made.

4. Yeast is added or native microbes are encouraged to propagate.

5. Alcoholic (Primary) fermentation begins, converting the natural sugar to alcohol and carbon dioxide (CO2).

6. Primary fermentation completes when the sugars are depleted.

7. Skins are pressed to get more wine product.

8. Malolatic (Secondary) fermentation is either encouraged or discouraged.  This converts the natural malic acid to lactic acid and carbon dioxide (CO2).

9. Secondary fermentation completes when the malic acid is depleted.

10. Optional Sulfur Dioxide (SO2) is maintained to avoid spoilage.

11. Optional bulk aging in tanks and barrels to allow clarification and maturation.

12. Wine is bottled and optional aged before release for consumption.

White Wine Process

Generally white wine is made using the same Red process steps.  Except step 1 (Crush) is replaced with step 7 (Press) to squeeze out the grape juice before fermentation.  No skins are included in white fermentations (except "orange" wines). 

When bulk wine is moved from tanks or barrels, the term is called "racking".  Read The Winemaking Process: "Rackings"  to learn about why racking is important as a process step.

(1) Grady Wann - University of California - Davis - Wine Production Lecture

The transfer of the wine, called racking, is a gentle process with one main purpose: separate the clear wine from the sediment.  The sediment is called lees and has fermentation byproducts that are no longer desired, like the dormant and dead yeast cells, bits of grape particulates, and other natural microbes.  These microbes were responsible for making the wine and have given many positive qualities, but their job is finished.  

The First Racking

The first time a wine is racked, the majority of the lees are left behind and removed.  The yeast cells autolyze (or burst open) and provide anti-oxidant protection and polysaccharides which improve the mouthfeel of the wine. The wine is now bulk aging in oak barrels, where it will slowly mature for the next year.  At this stage the wine is still “alive” and can evolve because it is not pasteurized.

Why Use Oak Barrels?

Oak barrels have a way of maturing wines that no other vessels have matched.  Barrels act as an environment and are not simply used as a container.  The barrel and wine interact with small amounts of oxygen to orchestrate all kinds of chemical reactions that create new flavors, but these are very slow and it takes 6 to 12 months for many of them to form.

Many large wineries try to reduce their costs with inexpensive plastic vessels, or very large stainless steel tanks with oak adjuncts that can simulate the conditions of barrels.  The oak adjuncts, like sawdust or oak extract, reduces the time and price of the wine so it can be rushed into the marketplace.

Wine Cost

There is no match for the quality of the wine that has been given the time to age in oak barrels, which most boutique and prestigious wineries choose to do.  Barrels are very expensive ($1000 or more).  Aging wines in hand-coopered oak barrels can significantly enhance the complexity and flavor quality, when winemakers are trying to achieve certain styles.  This is one difference between a $12 bottle and a $24+ bottle of wine. Another main cost is the grapes themselves (a future topic).  

Barrel Aging to Achieve Stability, Style and Complexity 

Have you seen a cloudy wine?  It generally indicates the wine is very young or not stable, had possibly spoiled, or was not allowed to properly mature before it was bottled.  Stability and aging are the topics of this discussion.

First: Stability

There are compounds in wine that form hazes and sediments that denature over time that lead to larger complexes.  If sufficient time is allowed for these reactions to occur during the aging of the wine, the particulate matter that forms can be removed using transfer techniques like racking. This reduces the need for clarifying additives, and allows racking to be the preferred clarification method. This is a gentle process that removes the unstable components and therefore the wine will be stabilized. Aging can be a means of achieving wine stability.

Next: Aging to Achieve Style and Complexity

When aging is done to add complexity, it may be done under conditions that add nuances to the wine, as with oak barrels. Allowing time is a way of aging to achieve style. New characters can be derived from yeast lees and oak when they are present during aging.

So aging in oak allows the formation of new characters, from oak cooperage and yeast lees, but the amount of complexity greatly depends upon grape variety and its chemical composition.  As new flavors develop, complexity increases. Thus aging can be used to subtract or add characters and to increase complexity. The increase in complexity can be considered as a multiplication effect. This is because a single compound can interact with several others, producing a spectrum of reactants. Some of the reactants can undergo further reactions, and complexity is greatly amplified. 

Small amounts of oxygen exposure during aging has some positive effects in red wines, but too much can be detrimental. Oxygen aids in reactions which can soften astringency and stabilize red wine color. These changes are critical to quality wines. The use of barrels means constant exposure to very small amounts of oxygen.  Winemakers need to periodically “top up” the barrels with extra wine to make up for the evaporative losses that occur with the porous wooden vessels.

Aging on yeast lees can be especially important in certain white wine styles, but red wines benefit too. Yeast autolysis (when cells burst open) adds flavor compounds into the wine.  This process also adds some anti-oxidant protection, and polysaccharides are released to add richer mouthfeel and help with the integration of oak characters, but it can take 6 months.

Finally, the size and toast-level of wine barrels have a strong impact on the style. Different from whiskey barrels, where barrels are shaped with steam and the inside quickly charred, wine barrels are bent using water over an open flame and once assembled, the inside is slowly toasted to bring out the vanilla and spice characters that we look for in our barrel-aged wines.  Surface area affects the reactions as well so larger barrels have less of an impact on the wine than smaller barrels because they hold more volume and have less contact with the wood.

What’s in the Bottle?

For oak-aged red wines, read the back labels.  Wineries that choose to spend the time and money aging their wine in barrels will often write the supplemental facts on their labels.  It's the only time they have the consumer’s focus on their bottle, and many will try to give the most important facts that make the quality difference.  

For stability, inspect the clarity by looking through the bottle and visually inspecting it.  Use an LED mobile flashlight to shine the beam through the bottle.  You can compare the visual beam in different bottles to know if it is slightly cloudy.  If you can see the beam, the wine has some particulates.  Cloudy doesn't mean “bad” if that was the winemaker’s intention.  Some unfiltered wines can turn cloudy after bottling.  Simply open it and enjoy it with a friend.

We grow our vineyard in an environment as natural as possible.  We employ organic and integrated pest management practices (IPM) like leaf removal in the fruiting zone to improve air circulation, have no till soils, and utilize cover crops like white clover to help keep the vines naturally nourished and healthy.  These practices reduce the need fungicide sprays.  

We also encourage native and beneficial plants like goldenrod, milkweed, dandelions and Queen Anne's lace (wild carrot) to attract a myriad of pollinators.  This attracts beneficial insects that help ward off pests.  We never spray insecticide or use any chemical weed killers in order to protect birds, pollinators, and the overall ecosystem.

The winemaking process comes with many challenges.  One major concern to most winemakers is the generation of unpleasant aroma byproducts, like sulfides.  When these "reductive" aromas are not mitigated, they diminish the quality of the finished wine.

We employ advanced monitoring methods to help improve our red wine fermentations that we believe produce more aromatic and fruitier wines.  We monitor and control the reduction-oxidation (Redox) potential by pumping small amounts of filtered air into the fermentation environment, but only as needed in order to keep it less reductive. 

Why?  Generally, when yeast are at their peak of activity, they consume all available oxygen for their life-cycle processes and reduce the Redox to negative levels, enabling other natural chemical byproducts.  Some of these byproducts are considered detrimental to wine quality.  The main byproduct from low Redox levels is the natural generation of hydrogen sulfide (or H2S).  These compounds are a natural part of wines, but detract from quality when they are in excess.  

When we use controllers to monitor Redox levels and introduce filtered air, we help keep the fermentation in positive ranges and greatly minimize any excessive H2S byproducts.

More Information: This is a trend in the wine industry that we decided to follow.  Some major wineries in California have employed these same techniques at large production scales.  

Read more about the Opus One study: https://www.winebusiness.com/news/article/202368

Read more about the UC Davis lab: https://engineering.ucdavis.edu/news/wine-redox-boulton-nelson

Small batch winemaking is the process of making wine in quantities typically less than 500 cases. This type of winemaking is often done by independent winemakers who have a close relationship with the land and the grapes they use. 

Small batch winemakers have more control over the winemaking process, which can lead to wines with higher quality and more distinctive flavors.

Here are some of the benefits of small batch winemaking:

🔹 More control over the winemaking process. Small batch winemakers have more control over the winemaking process than large-scale winemakers. This is because they are able to make decisions about the grapes they use, the fermentation process, and the aging process. This level of control can lead to wines with higher quality and more distinctive flavors.

🔹  Greater attention to detail. Small batch winemakers typically pay more attention to detail, such as the temperature of the fermentation process and the amount of time the wine is aged. This attention to detail can lead to wines with more complexity and nuance.

🔹  More creativity. Small batch winemakers are typically not bound by the same ​restrictions as large-scale winemakers. This gives them more freedom to experiment with different grape varieties, fermentation techniques, and aging methods. This experimentation can lead to wines with more unique and interesting flavors.

Overall, these benefits can lead to wines with higher quality, more distinctive flavors, and greater creativity. If you are looking for a wine that is truly special, then seek out boutique wineries that produce small batch wines.