Fruit Set

Fruit set in the Vineyards

As the growing season in the Paso Robles Appellation progresses we are quickly moving through the fruit set stages in the vineyards.

Usually in the months of May and into early June, fruit set starts to occur when flowers on the vine start to form into berries; the berry forms around the seed as it’s protection. Not every flower gets fertilized and eventually will fall off of the vine.  This is referred to as self-thinning, which naturally allows the crop to regulate its production for the year. During fruit set, the grapes are green and hard to the touch. These stages are an important part of the annual growth process because it determines the crops production for the year.

We are projecting a healthy, happy crop this year and very much look forward to sharing it with you!

Follow our educational newsletters to learn what’s going on in the Riverstar Vineyards throughout the year.


Veraison in the Vineyards

“In viticulture (grape-growing), veraison is the onset of ripening. The term is originally French (véraison), but has been adopted into English use. The official definition of veraison is “change of color of the grape berries”.  Veraison represents the transition from berry growth to berry ripening, and many changes in berry development occur at veraison.”

Veraison happens when the grapes on the vine start to change color. During this process the fruit acidy starts to decrease as the malic acid starts to break down while sugar concentration increases.

Often taking place in mid-July you will notice red grapes turning purple and white grapes turning into a beautiful golden yellow hue. Over the course of veraison you will notice an increase in volume, weight and sugars in each cluster of grapes. No one has an explanation of what sets off veraison, but is believed to be after the seeds have reached maturity.

From small hard berries to growth and color change; this may be one of the most exciting parts of the annual growth in a vineyard. It means harvest is just right around the corner!

Our First Harvest, 2016

The 2016 Harvest is Here!

It’s what we’ve all been waiting for! All of 2016’s hard work has finally paid off and now it’s time for one of the most important steps in wine making, harvesting the wine grapes!

Harvest is determined by the level of acidity, sugars and tannin primarily based on the winemaker’s personal preference and style of wine making.

Typically starting in August and ending in October, varying on different regions and climate conditions, each individual varietal will be picked in its prime condition for the region it grows in.

During Harvest, various types of picking methods will be used to pull the grapes off of the vine. These methods are called mechanical harvesting and hand picking.

A mechanical harvester works by hitting the vines with a rubber device until the grapes fall onto a conveyor belt and then into its holding bin. This technique is used all over the world as a much more economical and reduced labor picking method.

Hand picking is a much gentler style of harvest and is used mostly as a preferred winemaker’s choice and to harvest in regions that a mechanical harvester could not reach. The main advantage of hand picking is sorting through and picking only the healthy bunches of grapes in a much gentler style.

August 17, 2016 marked the first pick of the year for Riverstar! We brought in only estate white varietal, Sauvignon Blanc. We very much look forward to sharing this years harvest with you. Cheers to a happy and healthy 2016 harvest!

Pumpover Vs Punchdown

What happens after harvesting the grapes?

Image from Wine Folly

During harvest we bring in the grapes by cold picking during the night or early morning. The grapes are de-stemmed into fermentation bins or into small open tanks that are cooled down with dry ice for a 3-4-day duration called a “cold soak”. The cold soak process is an important step that promotes optimal color extraction from the grapes skins. On the last day of the cold soak we let the “must” (freshly pressed fruit juice that contains the skins, seeds, and stems of the fruit) warm up which allows the fermentation to begin with the native yeast that’s contained in the “bloom” (white residue on the grapes). The native fermentation will create a more complex finished wine. During fermentation the berries and skins will float up to the top from all the CO2 that is produced by the yeast while the grapes are fermenting. This creates what is called the “cap”. We try to keep the skins in contact with the juice as much as possible to extract as much flavor and color as possible. To do this, we use a process called “punch downs”. By punching down the cap we are pushing the skins back down using a punch down tool or process called “pump overs”. Pump overs are when you take the juice from the bottom the fermentation vessel and pump it over the top of the cap. Once the fermentation is finished (the yeast has eaten all of the sugars) we drain as much of the wine as possible and press the remaining must to extract as much wine out as possible without overly squeezing the grapes. Over squeezing can extract bitter and undesirable compounds.

One of the best parts about being a wino is learning everything you can about it! From the vineyard to the bottle we hope you can take a piece of our educational journey with you!