Harvest Terms You Need to Know

September in the Northern Hemisphere is a huge month for winemakers.  Wine lovers should be aware of the following vocabulary, especially if you’re visiting a winery:

• Alcoholic fermentation:   the conversion of grape sugar to alcohol

• Battonage:  stirring the wine during fermentation so that the liquid has contact with the lees (the solids)

• Brettanomyces:  bad yeast that causes wines to spoil

• Brix:  measurement of the amount of sugar in the grape

• Carbonic maceration: fermenting whole clusters of grapes that have not been crushed

• Fining:  process used to clarify the wine (egg whites are used by many)

• Free-run juice:  juice that has not been pressed but obtained simply by the weight of the grapes themselves

• Malo-lactic Fermention:  Known also as “ML,” this is the conversion of harsh malic acid to softer lactic acid

• Must:  unfermented grape juice

• Lees:  sediment that occurs during fermentation (includes spent yeasts, seeds & other solids)

• Racking:  process of separating the wine from the sediment by moving the liquid to another barrel

• Saignee:  French term which literally means “to bleed,” this is the process of removing some of the unfermented grape juice to increase the wine/skin ratio

• Sulfites:  chemicals that prevent spoilage of wine

• Tannin:  compound found in the seeds, skins and stalks of grapes

• TCA:  abbreviation for the destructive chemical that causes cork taint

• Topping-off:  process of filling a wine barrel that has lost wine due to evaporation

Grape Harvest 101

The wine harvest has already begun in many regions in the northern hemisphere.  There is basic vocabulary that any wine lover should know about the harvest.  This week we’ll concentrate on pre-harvest wine terminology and important facts.  Next week, we’ll address the process of actually making wine.

Green Harvest  

                             Extra fruit is pruned from the vine during green harvest

This type of “harvest” actually takes place early in the summer.   Bunches of grapes are removed from the vine, sacrificed in the name of quality (the unripened grapes are literally cut and tossed on the ground).  Fewer grapes on the vine means those that remain receive all of the nutrients, thus producing more concentrated, more complex wines.   It’s the concept that “less is more.”

Ripeness

         While grapes may appear ripe & have sufficient sugar, other elements may not be ripe

This is not as simple as it sounds.  It’s not just about the sugar level of grapes (known as “brix”).  Physiological ripeness, a fairly recent concept, is the key.  This means that all of the chemicals, not just sugar, inside the grape are mature.  These chemicals include components such as acids, tannins, and the phenolic components in the grape’s skins that are responsible for color, aromas and flavors.

Verasion

                             The change of color, Verasion, signals the approach of the harvest

This is a French word that has become part of the English vocabulary relative to wine-making.  The term is used to describe the actual change of colors in the berry from green immature fruit to their fully ripened color.  While this color change is one element in ripening, there are many other processes occurring inside of the berry to make it physiologically ripe.

Ripening Differences Among Grape Varieties

Different varitetals ripen at different times.   Dry white wine grapes ripen earlier than most reds.  Merlot ripens earlier than Cabernet Sauvignon.  Tempranillo, from the Spanish word temprano which means “early,” is the earliest ripening red grape in Spain.  Sweet wine grapes are the last to be picked so that sugars can be maximized.

Tune in next week for a primer on the need-to-know terms associated with the wine-making process.

Flavor Ripe vs. Sugar Ripe ?

                                                      

The grape harvest in California is just around the corner.  With the huge amount of sunshine we’ve received this summer, there should be no problem in ripening the fruit.  Most of us would think ripe means sweet….after all, how many times have we heard a winemaker discuss picking grapes at a certain level of “Brix?”  (Brix is a test that measures sugar content.)  This indicator, however, is not the only indicator of what makes a great wine.   As scientists have refined their understanding of the ripening process, winemakers are now steering away from using a single index of grape maturity.

Without going too science-nerd on you, let’s review what happens to grapes during their final stages of ripening. The most noticeable changes occur in their exterior skin colors.  Called “verasion” (when a red wine grape, such as Cabernet, changes from green to red and then to black) color pigments are deposited in the grape’s skin.  Verasion also occurs in white wine grapes when colors change from green to yellow and then to deep golden.  These are just the tip of the iceberg to the unseen chemical transformations occurring inside the grapes.

The interior of the fruit is busy accumulating sugar.  At the same time of increasing sweetness, another important process is occurring:  acid levels are dropping.  But, these are just two of the many complex physiological alterations inside the grape. Tannins also are changing, becoming less aggressive and bitter-tasting.   Other biological are underway making the grape taste less herbaceous.  All of these changes are highly significant to the winemaker.

Today’s winemakers view ripening as two completely different processes.  Sugar ripeness refers to the breakdown of acids and simultaneous accumulation of sugar.  Flavor ripeness (physiological ripeness) encompasses all the other complex chemical changes, such as tannins softening, skin pigments darkening.  In a perfect winemaking world, both of these processes would occur simultaneously.  They do not. 

Sugar and acid balance are instrumental in making wine, but they are not the perfect indicator of a great wine.  Sugar and acid balance cannot predict the ripeness of flavors or aromas.  In spite of a plethora of modern technology, there is no single index for determining flavor ripeness.  In fact, the best determinant for verifying physiological ripeness is very low tech---taste.  In concert, the winemaker must rely on experience and instinct as most of the fruit flavors aren’t released until fermentation.

Next time you’re having a glass of vino, focus on the aromas, flavors and mouth-feel.  These come from flavor ripeness.