fermentation

  • I'm Not Done Yet: Fermentation

    September 28, 2017 07:16

    The theme of harvest this month includes the end of harvesting grapes but the cellar crew doesn’t consider harvest over until the last tank of wine has been fermented and pressed and sent to rest and await barreling in the winter. The process of fermentation, which transforms the sugar in the grapes to alcohol through a little chemical magic utilizing yeast, is the beginning of wine. The vineyards have done their work growing the grapes but once they are in the tank it is the winemaking crew that begins the transformation from a sticky mass of juice and berries to new wine.

    We use temperature controlled stainless steel tanks to hold the must-which is a combination of the juice, skins and seeds transferred from the crush pad. If the grape is a white varietal like Sauvignon Blanc the must goes directly to press where the skins and seeds aren’t needed and then is transferred to tank for fermentation. Red wine grapes like Zinfandel go directly past the press and into the tanks. In the case of both white and red grapes the must rests for 24-48 hours to chill before yeast is introduced to begin the fermentation. This gives it time to cool down and the importance of this is to slow the process down to give time to the actual fermentation. Akin to a race horse, the juice is raring to get out of the gate and finish-which doesn’t allow for development of flavors. The winemaking team chooses the right yeast for the right grape in order to get the best out of the grape.

    Another way to get the flavor developed is to pump over the cap. The skins and seeds naturally rise to the top of the tank so the juice is pumped up and over the cap-kind of like the immersion of a tea bag where you get more color and flavor when immersed. This occurs every day until fermented dry-every last ounce of sugar is converted to alcohol. Skins and seeds float in the tank.

    Some wines go through the secondary fermentation called malo-lactic fermentation. Quick definition: malic acid is similar to tart green apple, lactic acid is similar to butter. Sauvignon Blanc and our Rose do not go through this process but part of our barrel fermented Chardonnay does and all red wines do. The reason? This secondary process softens the wine and instead of rustic rough edges you'll have one with smoother mouthfeel (or palate appeal).

    Now that we are finished with the fermentation the next stop is the press (for red wines) to remove the skins and seeds. The resulting mass is called pomace. It is taken up to the vineyard to 'season' for a year and then we add it back to the soil. Now we're done with harvest-in real time it will be mid-October before the final pressing. Until then I'll toast this harvest with a splash of Sauvignon Blanc!

  • More harvest know-how: The Cellar

    September 25, 2015 14:08

    Pressing matters. Literally. Once the red wine tank is done with its’ primary fermentation it is time to put the young wine through the press which separates the skins and seeds from the newly fermented grape juice. The skins and seeds are conveyed away and are now known as pomace. The pomace will be spread around the vineyards in a year, after it has taken the cure under a tarp.

    Once the pressing is done the wine is transferred to another tank for its’ secondary fermentation. This is known as malolactic fermentation and turns a somewhat harsh acid to a milder one. Think tart green apple (malic acid) turned to softer butter-like acid (lactic) by introducing lactic acid bacteria. If you have heard of ‘buttery’ Chardonnay it is likely it underwent malolactic fermentation. In red wine the process is there to do its’ job of making the wine more palatable. How long does all of this fermenting take? 2-3 weeks typically. We’ll be finished soon-and then the wine will rest before being transferred to barrels in January. A toast to the harvest and all the people who made it happen!

    This is a shot from harvest in 2006 of Humberto De La O (now retired) is pictured here overseeing the pressing of one of our red wines. Photo credit: Hipolito Cano, Cellar Master.

    2006 Humberto pressing wine

  • Harvest Know-how: Pump Overs

    September 18, 2015 14:19

    Harvest know how takes focus from when to pick the grapes to how long fermentation lasts, and everything in between. Today I am taking a look at the term pump-over and what this process does to increase wine quality during the fermenting process.

    Beginning at the crush pad, the bunches are destemmed. The grapes (now berries with a lot of juice) fill the tank and are inoculated with the yeast chosen for the varietal. The process of converting sugar in the ripe fruit to alcohol begins. A tank full of red wine grapes typically takes about 10 days to finish fermentation. Technology stepped in years ago to help the cellar crew slow the process. They found the longer fermentation takes the more you get out of the grape and the quality of wine goes up. The new technology has been a part of our cellar since the 1970s.

    Thanks to our Cellarmaster Hipolito Cano, here is a bird's eye view of a pumpover.

    Pumpover 2015

    The pump-over process is designed to get the most out of the cap that floats to the top of the tank. The cap consists of skins and seeds. The pump-over method has the fermenting juice pumped from the bottom of the tank over the top of the cap-thereby soaking the juice in the skins where all the color, tannins and flavor are located. The increase in all three of these important characteristics helps to make a better wine. This takes place three times a day during the length of time it takes to ferment dry.

    A toast to the cellar crew with a splash of Zinfandel in my Dino!

  • Harvest 2014 Ends

    September 25, 2014 15:34

    To recap, we began on August 19 with Sauvignon Blanc and ended with Cabernet Sauvignon on September 24, 5 weeks and two days later. One of the great things about writing a newsletter since 1990 is I have copious copy illustrating our harvests year after year. There is quite a bit of talk about this being a super early vintage so I looked up the ‘earliest’ harvest we have recorded which is 2004 when we picked Sauvignon Blanc on August 11 and I see we brought in Cabernet Sauvignon over Labor Day weekend. We finished early in the third week of September.

    This year it was a very compressed harvest for a couple of reasons: the weather stayed with us and didn’t cool off or heat up too much and some vineyards ripened ahead of schedule. For instance we picked estate Merlot before our growers harvested their Pinot Noir and Chardonnay. The second reason has to do with availability of picking crews. Manuel Diaz, Vineyard Foreman, said he had a steady supply of men and women to do the picking-in other years we had to wait until a full crew could be mustered, hoping the grapes would hang in there until they could bring in the fruit. While it is a few more days until we finish fermentation, here's a toast to all of our hard working crews in the vineyard and cellar on our 87th harvest!

    2014 Harvest Gondola