Wine Education

Wine Education Seminars: Status Update

Our wine education seminars have been such popular events this past year! In early 2020, many of you have enjoyed our seminars on: “Intro to Wine and Wine Tasting” (January) and “Wine, Chocolate and Other Perfect Pairings” (February).

We are disappointed that due to COVID-19 we had to cancel our remaining 2020 seminars on “Wines of Spain,” “Wines of Germany & Austria” and “Wines of North America.”

However, as soon as conditions permit, we will re-schedule these, and more wine education seminars. We may have smaller class sizes and will need to follow guidelines for social distancing, but rest assured, there will be plenty of wine tasting!

Thank you for your patience and understanding. We will notify you as soon as we can safely reschedule these seminars.

– Irene Scott, Wine Education Chair

Wine Education 101: Get to know the Alsace Wine Region

Alsace is not one of the more famous wine regions in France, but is certainly the most unique.  Alsace is one of the most northerly wine regions in France (Champagne is furthest north) and lies in the northeast corner of France along the German border and the Rhine river.  It is a small wine region running north and south, about 75 miles long and averaging about 3 miles wide (not all under vine).

Surprisingly, Alsace, lying so far north, receives some of the lowest rainfall in France.  This is because Alsace lies in the rain-shadow effect of the Vosges Mountains, protecting it from Atlantic influences and keeping it warm and sunny.  This northerly climate along with the warm sunshine, results in ripe grapes with complex aromatics.

Alsace also lies along the Rhine graben, part of a long trough that zigzags across Europe with Alsace on one uplifted side and Baden, Germany on the other uplifted side.   Also unique to Alsace is that it contains 13 different major soil types, the result of ancient years of earth movement and erosion.  Some of the best soils for viticulture are found on the slopes of the Vosges Mountains.

What is most unique about this small wine region is its blend of both French and German cultures.  This amalgamation of cultures is a result of the region being forced back and forth in nationality between Germany and France.  Alsace was a German principality in mid-Renaissance, but was annexed by France at the end of the 17th century.  Alsace was reclaimed by Germany at the end of the Franco-Prussian War.  Alsace was then returned to France at the end of World War I, only to be occupied by Germany during World War II.  At the end of World War II, Alsace was once again returned to France.  The result of these transitions of allegiance was a beautiful blending of cultures, language, cuisine, and especially its wine.

Unlike other French wine regions, Alsace wines are labeled in the Germanic tradition – by grape varietal, rather than the French tradition of place.  Alsace also uses the long, tapered flute bottles as is traditional in Germany.

With its continental climate and 13 different soil types, Alsace land supports a wide diversity of grape varietals.  There are seven primary grapes of Alsace:  Riesling, Pinot Blanc, Gewurztraminer, Pinot Gris, Pinot Noir, Sylvaner, and Muscat.  Secondary grapes include:  Chardonnay (for Crémant production), Chasselas, Auxerrois Blanc, and Klevener de Heiligenstein.

Out of all these grape varietals produced, the four “Noble Grapes of Alsace” are Riesling, Gewurztraminer, Pinot Gris and Muscat.  These are the approved grapes for Alsace Grand Cru AOCs (with Sylvaner approved for one Grand Cru).  90% of wines made in Alsace are white.  While the wines of Alsace are greatly influenced by their German neighbors, they have qualities distinct to Alsace.  When most people think of these four noble grapes, they may think of sweet wines, as often in Germany.  But in Alsace, these wines are traditionally fermented dry and in stainless steel tanks or neutral barrels.  These wonderfully aromatic varietals, in combination with the northerly climate, variety of soils, and abundant sunshine in Alsace, produce wines that have bright acidity, crisp minerality, fresh fruit and floral aromas, full-bodied, with spices and richness unlike other white wines.  You may think that you are already familiar with Riesling, Gewurztraminer, Pinot Gris, and Muscat varietals – but you have not truly experienced the full character of these wines until you have tasted those from Alsace.

Alsace also produces Pinot Blanc (also known as Klevner), having perfumed and smoky notes, and Pinot Noir, which is distinctly lighter and often used in Sparkling Rosés.  You might also come across a Pinot d’ Alsace which is usually a blend of Auxerrois Blanc, Pinot Blanc, Pinot Noir (vinified as white), and Pinot Gris.

Also not to be missed is the Cremant d’ Alsace, the second most popular sparkling wine in France, made in the same méthode traditionnelle as Champagne.  While Alsace lies nearly as far north as Champagne, the climate is warmer and drier so that the grapes reach greater ripeness and have more round, generous flavors. Often made of crisp Pinot Blanc, Cremant d’ Alsace has a creamy texture (from a minimum 9 months sur lie aging) and can have aromas of crisp apples, citrus, honey, yeasty-notes, toasted, buttered brioche and marzipan.

To top this off, Alsace makes incredibly delicious dessert wines.  Late harvest wines made of the four noble grapes, often affected by botrytis (noble rot) are labeled as “Vendanges Tardives”.  These wines are sweet and honeyed, often having a full-body and high alcohol.  Another Alsatian dessert wine is the “Sélections de Grains Nobles”, also a sweet, late harvest wine made of the four noble grapes.  These late harvest wines must be made from botrytis-affected grapes and are hand-picked, berry by berry, through multiple passes in the vineyard.

This small region of Alsace, certainly not the most famous wine region in France, offers up a bounty of wine experiences as full and diverse as their rich culture.  Taste these Alsatian wines and your senses will be delighted by the fresh fruit and floral aromas, accompanied by perfumed richness and exotic spices. With warm weather approaching, these crisp refreshing wines from Alsace should surely be on your summer wine list.

Irene Scott, WSET-3 – Wine Education Chair

Refererences:

Wine Scholar Guild, French Wine Scholar Study Manual, 6th edition, ISBN 978-1-4835-8560-4

Robinsons, Janice.  “Alsace”.  https://www.jancisrobinson.com/learn/wine-regions/france/alsace

Wine Folly, “Alsace Wine Region: A Manual for Oenophiles”, Sept 12, 2019. https://winefolly.com/deep-dive/alsace-wine-region/

Wine Education 101: Blood, Guts, Bones and Mud in our Wine?

You might think that wine, a product made from grapes, should be “vegan” – not containing any animal products.  This is not necessarily the case for many of our wines today.  In winemaking, there is a process where the wine needs to settle and clarify so that ultimately the bottle of wine that we open is clear of sediment and haze.  Left on its own to occur naturally, this process could take up to a year to settle and produce a clear wine.  Further fining might also need to be performed to remove undesirable constituents such as excessive astringency or bitterness.  In order to accomplish this settling and fining of wines more efficiently, winemakers may use a variety of additives to speed up and enhance this process.  So, could there really be blood, guts, bones and mud in our wine?

The process of “fining” utilizes a substance (often a protein) that is mixed into the wine barrels or tanks.  The substance is attracted to small, suspended particles in the wine that could make the wine cloudy or hazy.  These larger, combined molecules will then precipitate (fall) to the bottom of the wine barrel or tank.  The “fined” wine is then removed from the top.  In theory, there should be little to none of the fining agent left in the “fined” wine. But what fining agents could possibly be left behind in that bright, clear bottle of wine?

In days past, a traditional fining agent used in winemaking was ox blood.  This was added to wine (as a liquid or in dried form) and was a very effective fining agent.  However, in 1997 both the EU and the US banned its use when the mad cow disease scare peaked.  Because of export restrictions of any wine containing blood, there is not much chance that your 25-year old bottle of Bordeaux wine you were saving contains any fining blood.

An effective fining agent used today is isinglass – something you may think of as “fish guts”.  Isinglass is made from the air bladders of fish – usually sturgeons.  It is an excellent fining agent for clarification and removal of bitterness and astringency in white wines.  While the correct use of isinglass can help unmask fruit character, over-use can impart your wine with a “fishy” aroma.

Another non-vegan fining product used in wine is gelatin. Gelatin is a protein made from boiled skin, tendons, ligaments, and/or bones (hooves) with water.  Gelatin is an aggressive protein fining agent that is primarily used to soften red wines by reducing tannins and astringency. Over-use of gelatin fining could result in color loss in red wine and protein instability.

Bentonite is probably the most commonly used fining agent for the clarification and protein stabilization of wine.  However, since it can also remove color, it is more often used in white wine.  Bentonite used in the U.S. is made from clay that is found in Wyoming (sodium bentonite); in Europe, Bentonite is made from clay found in South Africa (calcium bentonite). When Bentonite is dry, it is hard and water-tight; when wet, it is slimy and slick.  Other uses for Bentonite include lubricating oil drill bits; an additive to animal feed (it swells and slows down digestion); used to treat diarrhea; is the mud in “mud baths” and in “mud wrestling”; used in fabric softeners (for ion exchange/water softening).  Bentonite is a very multi-purpose wine fining agent!

A very traditional fining agent for red wine is egg whites, or Albumin (made from chicken egg whites).  This fining agent helps to remove astringency and bitterness and is a good general finishing “polish” for red wines.  Egg whites are not as effective in white wine as it needs the presence of tannins to flocculate.  While the egg whites flocculate with tannins and precipitate to the bottom of the barrel/tank to be later racked off, those with an allergy to eggs might still have reason to be concerned.

Another fining agent that has potential allergy concerns is Casein (potassium caseinate) – the principal protein in milk. Today, Casein is mostly used in its purified form, but skim milk was used in the past and still may be in use today.  Casein is a very gentle fining agent and works well in removing over-oaked aromas, oxidized aromas and browning in white wines.

There are many more products in the winemakers fining “toolkit” today including mineral compounds, polysaccharides (such as chitin found in the covering layer of insects and in the cell walls of fungi), and synthetic polymers (plastics like PVPP).  Most of the products used for fining will precipitate to be bottom of the tank/barrel and be racked off – leaving little or no presence behind in the finished wine.  It is possible that you may find “un-fined” wine – but this can be challenging as even the most traditional Bordeaux wine regions commonly use fining.

Currently, the Alcohol and Tobacco Tax and Trade Bureau (TTB) does not require the disclosure of major allergens on wine labels.  However, there is a current proposal to make labelling of major food allergens on alcohol labels mandatory.  To read more about this, visit: https://www.ttb.gov/faqs/allergen-labeling.

So, perhaps you may have a greater appreciation (or more disgust) for what it takes to make that finished bottle of wine clear and free of sediments and haze.  Cheers!

Irene Scott, WSET-3 – Wine Education Chair

Sources:

Wann, Grady, “Fining and Stability”, UC Davis Extension, 2020.

Jackson, R.S., Wine Science: Principles and Applications, Academic Press, 2014

Wine Education 101: Winter Dormancy in the Vineyard

We all love to see beautiful vineyards at harvest – green, full vines with abundant clusters of red or green grapes. Harvest is an exciting time as the vines bring forth their bounty and then take a deep sigh of relief. Following harvest, the vines decorate the landscape with vibrant hues of yellow and orange. But sadly, the vines then give up their leaves to become brown, bare twigs in the ground by winter. But are these vines really as lifeless as they appear? Contrary to their appearance, these vines have prepared themselves to survive and thrive during the cold winter months.

To understand the winter dormancy period, we first need to understand the annual growth cycle of the vine.

Budburst – March-April in Northern Hemisphere (September-October in Southern Hemisphere).

As temperatures begin to exceed 50oF, buds begin to swell and burst open to later become new shoots. Some grape varietals experience bud burst earlier or later than other varietals. Frost at this time can significantly damage these buds and the following early shoots. It is interesting to know that buds will form for the current year’s crop, and also for the following year’s crops (remaining dormant until the following year).

 

Early Shoot and Leaf Growth – March-April in Northern Hemisphere (September-November in Southern Hemisphere.  Shoots develop and begin a period of rapid growth, spawning budding leaves and tendrils. Until leaves mature and can support photosynthesis, this growth is fueled by carbohydrates that have been stored in the woody vines and roots following harvest. Green leaves begin to fully develop as shoots mature to reach the flowering stage.

 

Flowering and Fruit Set – May-June in Northern Hemisphere (November-December in Southern Hemisphere)

Depending on temperatures, about 40-80 days after budbreak, flower clusters will begin to appear on the end of the shoots. Most cultivated grape vines are “hermaphroditic” containing both male stamens (pollen) and female ovaries (seeds). With a few weeks of some warm sunshine, flowers grow and lose their protective “cap”, leading to “fertilization” with the next gentle breeze. Unfertilized flowers will fall to the ground, sadly never to become a grape. This stage of the vine lifecycle is critical to development of a healthy crop yield and can be damaged by cold, harsh and rainy weather.

Véraison and Berry Ripening – July-September in Northern Hemisphere (January-March in Southern Hemisphere)

After fruit set, both white and red grapes are hard green berries that are low in sugar and high in acid. These berries continue to grow in size for the next 40-60 days followed by “véraison.” This is the time that berries begin to soften and change color, becoming red, purple, black, or a more translucent, golden green. Warm, sunny weather is needed at this time for the grapes to ripen and accumulate sugars.

Harvest – September-October in Northern Hemisphere (March-April in Southern Hemisphere)

Grapes have reached their peak ripeness: sugars and pH have increased, while acids (such as malic) begin to decline. Tannins and other grape phenolics have matured, giving rise to enticing aromas and flavors. Grape clusters are removed from the vines to begin their journey into becoming wine.

After harvest, leaves remain on the vine where they continue to perform photosynthesis and produce carbohydrate reserves. Eventually, the vines begin to pull back these carbohydrates from the leaves to later be stored, causing the leaves to turn brilliant shades of yellow, orange, and eventually brown. Be aware that red leaves on the vines are not a typical harvest color and often indicate the presence of vine disease.

Now that vines are no longer spending energy producing fruit, their energy can now be spent in their root system. Many new small roots begin to grow and seek out vital nutrients in the soil in a process known as “root flush.”

Winter Dormancy – December-March in Northern Hemisphere (July-September in Southern Hemisphere)

By winter, vines have stored their nutrient and carbohydrate reserves in the cordons, woody trunk and roots. These reserves are critical so that the vines have energy to produce budburst and new shoots in spring – a time when there are not yet leaves on the vine to produce carbohydrates via photosynthesis. Also important is that vines have gone through a dehydration process so that water does not freeze within the vine and root tissues during the cold winter months. Damaging cold winter frosts are not a typical problem in California growing regions – but can be a serious problem in many colder regions.

However, this cold “winter dormancy” is vital to the growth cycle of vines. Temperatures must become cold enough that the above ground vine growth will halt. This cold resting period is necessary to ensure normal budburst and growth cycle in the spring.

Winter dormancy is also the time for winter pruning to be performed. This pruning sets the stage for the next years growing cycle. Woody canes from the previous year’s growth are cut off and new canes are selected from which the new shoots will grow come springtime. This pruning also stimulates the vines so that when warmer weather and sunshine arrive, the vines awaken to a new growth cycle.

So, next time you pass a dormant field full of bare, woody vines, just know that the vines are preparing themselves to greet the spring sunshine with a burst of new growth and start making grapes for your next great bottle of wine.

Irene Scott, WSET-3 – Wine Education Chair

References:

Wine and Spirit Education Trust, 2016. Understanding wines: Explaining style and quality. wsetglobal.com, London, UK.

Urska (2018, Dec. 5). Grapevines During Winter Dormancy, Evineyardapp.com.

Burgess, Laura (2016, Jan. 29). Below the Surface: Winter in the Vineyard, Vinepair.com.

Wine Education 101: Celebrating the Holidays with Sparkling Wine

The holidays are the perfect time of year to celebrate with a glass of bubbling sparkling wine. Those little bubbles in your glass give rise to an explosion of festivities, sparkles, and celebrations – maybe even a few giggles! Sparkling wine is a holiday favorite because it can be found in many different styles, which is what makes it so versatile and easy to enjoy with hors d’oeuvres, dessert, and yes, even with your main course. With so many sparkling styles to choose from, how do you select the best bottle for your celebrations? To start with, we should understand what sparkling wine is and answer the most common questions surrounding it, such as:  1) What is the difference between Sparkling Wine and Champagne?; and 2) Which is dryer, “Extra Dry” or “Brut”?

While all bubbling wine may be considered sparkling wine – not all sparkling wine is Champagne.  If a sparkling wine is labeled as “Champagne” it likely has been made in the region of Champagne, France using the “method champenoise” (also known as “traditional method”).  This method starts with a dry base wine in a bottle, followed by the addition of a solution of sugar and yeast.  This causes a secondary fermentation in the bottle to occur with carbon dioxide bubbles as a by-product.  As the bottle is aging, it is manipulated and angled (a process called “riddling”) such that the “lees” (dead yeast cells) move down into the neck of the bottle. When the aging process is complete (about 1.5 years), the lees are frozen in the neck, and then later expelled by the bottle pressure when the bottle is uncapped.  The Champagne may then be quickly adjusted for sweetness (“dosage”), and blended with small amounts of previous vintages (for consistency) before it receives its final cork.  Most Champagne is non-vintage, unless an exceptional harvest is declared.

Some quality sparkling wines are also made with the above “traditional method”, while less expensive sparkling wines may be made by the Charmat (Tank) method.  This method puts the base wine into a pressurized tank and adds yeast and sugar so that the secondary fermentation takes place in the pressurized tank and is later bottled using a counter pressure filler.

Which sparkling wine is driest?  Here is a guide to the sweetness level of sparkling wine (from Dry to Sweet):

  • Brut Zero or Brut Natural: no sugar (dosage) has been added – typically < 3 g/L residual sugar
  • Extra Brut: < 6 g/L residual sugar
  • Brut: < 12 g/L residual sugar
  • Extra Dry: between 12 to 17 g/L residual sugar
  • Dry (Sec): between 17 to 32 g/L residual sugar
  • Semi-Dry (Demi-Sec): between 32 to 50 g/L residual sugar
  • Sweet (Doux): 50+ g/L residual sugar

Typically, French Champagne is produced using Chardonnay, Pinot Noir, and Pinot Meunier.  You might notice bottles with these labels that indicate which grapes were used:

Blanc de Blanc:  A French term meaning “white from whites” – this is white Champagne made exclusively from the white Chardonnay grape.

Blanc de Noir:  A French term meaning “white from blacks” – this is white Champagne made from black grapes (Pinot Noir, Pinot Meunier).

Cuvee de Prestige A French term meaning “Prestige Cuvee” – this is typically a proprietary blend of premium quality Champagne, usually made from the vintner’s finest grapes in their best vineyard.  These Cuvees are usually designated with a vintage, and carry a premium price-tag.

Here are some other types of sparkling wine that you might find from around the world:

Cremant – this is sparkling wine made in France (outside of Champagne region) using the method champenoise (traditional) method.

Asti (Spumante) – This is a sweet sparkling wine made from the Moscato grape in the Piedmont (NW) region of Italy.

Proseco – This is an aromatic and fruity sparkling wine made from the Glera grape in the Veneto (NE) region of Italy, usually with the cheaper tank method.

Cava – This is sparkling wine made in Spain from a variety of regional grapes with varying levels of sweetness.

Sekt – German sparkling wine has a variety of quality levels with Winzersekt being at the top of the list.  This bubbly is usually made from the Riesling grape using the traditional method.

Now that you have picked out your favorite bubbly, how should you serve it?  Champagne and sparkling wine should always be served cold; its ideal drinking temperature is 45 to 48 °F.

So, let’s raise a glass of our favorite sparkling wine and toast to the coming Holidays and New Year!

Irene Scott, WSET-3

Wine Education Chair

Wine Education 101 – Holiday Food and Wine Pairing

The Holiday Season is almost here and we know what that means – lots of delicious food to be enjoyed with our favorite wines in the company of our dearest friends and family. But choosing the right wine to complement our holiday meals can sometimes be confusing. We have all heard that we should drink red wine with red meat, and white wine with fish, but why? To understand food and wine pairing, we first need to know the five basic tastes we detect in food that are the basis for pairing with wine: 1) sweetness, 2) saltiness, 3) bitterness, 4) acidity, and 5) umami (savory). So, how do these five flavor components impact your holiday wine pairing?

Sweetness in food can increase the perception of bitterness, astringency, and acidity in wine. Sweetness can also decrease the perception of body, sweetness, and fruitiness in wine. A good general rule with sweet food is to pair it with an even sweeter wine.  Think of that holiday apple pie paired with a late-harvest Riesling, an ice wine, or a Sauternes.

Saltiness in food is very friendly in pairing with wine. Salt in food can increase the perception of body and fruitiness in wine while also decreasing the perception of astringency, bitterness, and acidity. Salty food should be paired with wines that are acidic, fruity, and crisp. Classic pairings are briny oysters with Sauvignon Blanc, or popcorn with Chardonnay (one of my favorites). Another holiday favorite is ham which is often a combination of sweet-and-salty flavors.  Pair this meal with a crisp Rose, off-dry Riesling, Gewurztraminer, or a soft fruit-forward Zinfandel, Grenache or Pinot Noir.

Bitterness in food on its own may be tasty, but it can increase the perception of bitterness in wine. Bitter food paired with a tannic red wine will increase the sensation of those tannins in the wine. It is best to pair bitter food with red wines that are low in tannins (such as Pinot Noir) or consider white or rose wines. Consider pairing those holiday Brussel sprouts or arugula salad with a Sauvignon Blanc or Chardonnay.

Acidity in food is good for pairing with wine. Foods high in acidity will increase the perception of body, sweetness, and fruitiness in the wine. Acidic foods will also decrease the perception of acidity in the wine; therefore, you must pair your acidic food with an equally acidic wine or else your wine will be perceived as “flat” and “flabby.” Acidic wines are also great for pairing with rich and creamy foods which coat the tongue and prevent other flavors from being released. The acidity in the wine cuts through creams, cheeses and rich foods to balance out flavors. A rich and cheesy holiday lasagna with its acidic red sauce pairs lovely with the high acidity of Sangiovese or Chianti.

Umami is a taste that is difficult to isolate and is often described as “savory.” Some examples of umami would be something meaty, mushrooms, corn, cooked tomatoes, seaweed, miso, soy sauce – fermented foods and those high in glutamate (yes, MSG). Umami in food increases the perception of bitterness, astringency, acidity, and the warming sensation of alcohol in the wine. Umami also decreases the perception of body, sweetness and fruitiness in wine. Umami without accompanying saltiness in food is difficult to pair with wine. However, the combination of umami and salt in food such as cured meats, smoked seafood and parmesan cheese will have less of a harsh effect on the accompanying wine. So, when your holiday meals contain “umami” dishes, make sure to prepare them in a way that adds some salt to the flavors. Good wine choices for foods high in umami are low in alcohol, crisply acidic, fruit-forward and even slightly sweet. Consider a crisp Chardonnay or Sauvignon Blanc, a fruit-forward Pinot Noir or Zinfandel, or even a sparkling Rose with your holiday turkey.

So how does this support the “red wine with red meat” and “white wine with fish” common practice? We all love our hearty Cabernet Sauvignon or Merlot along with our aged prime rib of beef served during the holidays. These big reds are softened as the tannins in red wine bind to the proteins in meat, which is often high in salt content as well.  Fish can also be high in umami which is why it is often paired with a white wine, being lower in tannin. A tannic red wine with fish would have increased perception of bitterness and astringency.

Serving holiday tamales? Be aware that spicy “chili” heat can increase the perception of bitterness, astringency and acidity, as well as the increase the burning sensation of alcohol in the wine. Foods high in spicy heat will also decrease the perception of body, richness, sweetness, and fruitiness in the wine. It is best to serve those holiday tamales with a lower alcohol white wine that has some sweetness and fruitiness while avoiding tannic red wines. Tamales might pair with a New Zealand Sauvignon Blanc, Gewurztraminer, or a Riesling.

I hope you have gained some insight on how the different tastes in food pair well, or not, with some of your favorite holiday meals. Keep in mind, however, that food and wine pairing can be very subjective and a matter of personal preference.  During the coming holiday season, I hope you enjoy delicious meals with your favorite wines amongst your dearest friends and family.

Irene Scott – OCWS Wine Education Chair

Wine Education 101 – Harvest Timing

In California, Fall is an exciting time of year for winemakers as it is grape harvest season and a time for new beginnings.  Most harvests in the Northern Hemisphere occur in the months of August, September, and October – while harvests in the Southern Hemisphere typically occur in February, March, and April.  In California, some early-ripening varietals, such as Sauvignon Blanc, Chardonnay, Muscat, and Pinot Noir, may be harvested in late August.  On the other hand, some late-ripening varietals, such as Cabernet Sauvignon, Cabernet Franc, Zinfandel, and Syrah, may be harvested in early November. Year to year climate variations will also affect timing of the harvest season, possibly causing a later than usual, or earlier than usual harvest.

The timing of the grape harvest is one of the most important viticulture decisions affecting the winemaking process.  The quality of the grapes at harvest establishes the potential quality of the wine early in the winemaking process.  Good winemaking practices may help offset some deficiencies in grape quality but cannot fully make up for deficiencies in grape flavor when the harvesting is done too early or too late.  As the saying goes, “You can make bad wine from good grapes, but you can’t make good wine from bad grapes”.

So, how is this important harvest timing determined?  Viticulturists, or grape growers, will often work with the winemaker and establish their targets for grape sugar, acid, and pH levels, along with goals for different flavor and phenolic components.  Grape color, berry size and texture can also be taken into consideration for harvest timing. These targets may vary from varietal to varietal as well as vary to each winemakers’ stylistic choice.

As grapes reach maturity, their sugar level rises, and this sugar has long been the standard for determining harvest timing.  Grape sugar measurements are done using a refractometer and are recorded in “Brix” (Bx), with a typical Brix measurement falling between 21oBx and 25oBx at harvest.  Warmer climates, such as in California, will obtain higher Brix levels, while cooler climates in Europe may struggle to obtain the minimum ripeness and Brix level.  Since during fermentation yeast convert sugar into alcohol, a higher grape or juice Brix level has potential for higher alcohol in the finished wine.

At the same time that sugar levels are rising closer to harvest, acid levels begin to fall.  Acid levels in wine are very important as they are the “backbone” of wine, giving it balance and structure, as well as being the key component in food and wine pairing.  The major acids in wine are tartaric and malic acids, with minor amounts of citric and succinic acids. Tartaric acid is nearly unique to grapes and has the most impact on wine flavor, so measuring of tartaric acid, known as “TA” (titratable acidity) is a key measurement in grape ripeness.  White wines typically have a TA level between 7 g/L to 9 g/L, while red wines typically have a TA level between 6 g/L to 8 g/L.

The pH level in the grapes is also measured, and has somewhat of an inverse relationship to the “TA”.  Low pH numbers indicate that there is a high concentration of acids in the grape juice (or wine).  So, as the grapes are ripening, sugar levels are rising with acid levels falling, resulting in an increase in the pH level.  If the pH level is too high, that may be a sign that the grapes are overripe and may impact the quality of the wine.  Most wines will have a pH reading between 3 and 4 on the pH scale.  White wines typically have a lower pH and a higher TA, giving it “crispness”, while red wines typically display “roundness” with a higher pH and a lower TA.

Measuring for the targeted grape properties begins with systematic berry sampling as the harvest season approaches – this is a collection of about 100-200 berries from different grape clusters within the varietal block to be harvested.  Care must be taken to obtain a truly representative sample from the entire harvest block.  Berries should be selected from different rows in the vineyard, sun exposure, location on the vine, and from different areas within the cluster.  Sampling usually begins about 3-4 weeks before the anticipated maturity date.  As harvest approaches, Brix levels often rise about 2o Bx per week so sampling at regular intervals is important.  After also evaluating berry color, size and flavor, the sample is processed so that sugar, acid and pH tests can be performed on the juice.  Often, seed ripeness is also evaluated as an indicator of grape maturity.  Brown seeds are considered mature while green, un-ripe seeds may impart undesired bitterness in the wine.

Once the targeted grape properties have been reached, the harvest is done quickly and usually during the cool evenings or early mornings so that heat does not encourage the start of early fermentation.  Harvesting can be done by hand or mechanical harvesters, both having their pros and cons but both serving to get those ripe grapes from the vineyard into the winery for the winemaking process to begin.

Making the decision to harvest grapes is a critical decision in the winemaking process and is dependent on many factors requiring precise timing.  So much more can be written on the process of winemaking after the grape harvest.  I encourage you to visit the OCWS Winemaker group at: https://ocws.org/winemakers-activities/  to learn more about winemaking.

  • Irene Scott

Wine Education Chair