“Ripeness is essentially comprised of two parts. One part chemistry which includes sugars and PH and another part intuition which includes flavors from the Vineyard Brownness of the seed (lignification) and tannins of the skin. When Randy and I go into the Vineyard to taste the Vineyard we are first visually looking at the clusters to see if there is any shriveling or pucker, we then are tasting berries noting the crunch of the skin when we initially put it in our mouth, and then looking for complex flavors of black cherry instead of regular cherry or in whites more tropical flavors versus just green apple flavors. It takes several years to develop a palate for tasting sweet grapes. We only get one time a year to practice this palate and our mouth is competing with 25 brix of sugar which makes it difficult to taste the nuances that you are looking for.”
Revealing the 5 Tell-Tale Signs the Grapes Are Ready for Wine Harvest
As Erik indicated, all those seeking The Great Grape are evaluating it in several ways. These include, but aren’t limited to:
Color of the grapes. Naturally, red grape varieties will gradually turn from green to red as they ripen. However, experienced winemakers know it could take many weeks, depending on the weather and the grape variety, before true ripeness sets in.
Color of the stems and grape seeds: When ripe they will be brown.
Added hints from grapes: They will plump up as sugars increase, and they will be easy to pull from a cluster the riper they get.
Added hint from grape seeds: Taste a grape and the seeds are easily chewable when ripe. They are also brown.
Flavor. Ripe grapes are sweet, with no hint of bitterness in the flesh or seeds. Experienced winemakers will look for the ultimate “varietal” flavors to show through.
In addition to this evidence of ripeness, winemakers also rely on technology to know when it is time to harvest the grapes. They’ll take a portable refractometer into the vineyard and measure sugar levels. The higher the sugar, the riper the grapes.
In the lab, they’ll look for pH and titratable acid (TA) levels. As grapes ripen, pH rises and acids drop. Both together give the winemaker an idea of the wine’s acidity.
What other concerns do winemakers have when they determine when its time for wine harvest? Here are a few shared with our wine club recently:
Quirks of the vineyard. Some rows ripen faster than others, depending on their sun exposure, altitude, exposure to wind, etc.
Type of Grape: Some grapes ripen faster than others.
Style of wine: If they are looking for terrific acidity, as in a Rosé, winemakers will be carefully watching those pH/TA lab reports.
Worker Availability: There may be a shortage of pickers that could delay harvest.
The Weather: Mother Nature may force a winemaker to harvest if she is threatening to dump a long period of cold rain, or, if temperatures keep rising and grapes are starting to dry up like raisins. Let’s face it — ultimately, Mom is in charge!
When grapes used to make wine are ready to be harvested, the winemaker can choose to pick by machine or to pick by hand for many different reasons.
Hand-picking is nearly always preferred for wine grapes, or for smaller vineyards that can't risk losing any fruit. For handpicking, all you need is a pair of secateurs and grape baskets (small bins) spread throughout the rows underneath the vines.
Quite simply, you clip or cut the bunches off each vine and place them into the baskets, making sure not to damage the vines and most importantly the grapes on the bunch. Then you carry, transport the grape baskets down the rows to possibly larger containers, or carefully packed onto a truck to be transported back to the winery.
Despite the added costs with hand harvesting, many wineries prefer the use of human workers to hand-pick grapes. The main advantage is the knowledge, skill and discernment of the worker to pick only healthy, ripe bunches throughout the vines and the gentler handling of the grapes.
The production of some dessert wines like Sauternes and Trockenbeerenauslese require that individual berries are picked from the botrytized bunches which can only be done by hand, as they will split during machine harvesting; this also includes 'late harvest' and 'ice wines'.
Hand Harvesting allows individual bunch selection based on ripeness - therefore fruit selection can be more exact, often selection is by single berry rather than a bunch and can be done repeatedly over many days, even weeks.
Hand picking can be employed on any terrain although unfavourable terrain (steep slopes, terraced hillsides) dramatically slow the progress and therefore increase the cost of doing this. Hand picking is also needed when vines are grown in a Pergola style - like those found in areas of northern Italy - also where you have very old, fragile, low cropping 'bush vines' that grow at different heights and in irregular patterns.
A good picker can harvest up to 2 tonnes a day. Hand picking is becoming quite common in New Zealand for premium wines where a great deal of time and energy has been invested in getting small, high quality fruit from carefully selected sites and rows. Plus some regions in Europe have regulations that do not allow mechanical harvesting
