The Big Squeeze

October 30, 2012

in Make Wine That You'll Drink

Wine making is akin to rearing children.  The goal is the same but the paths are many.

After the crush and the journey home, the crushed grapes now called must, start their 48-hour cold soak.  Decreasing the must temperature to 55-59º F helps keep the bacterial and wild yeast count low.  This “suspended state” also provides additional time for the raisiny berries to release their sugars and gives the juice additional contact time with the skins.

Untoasted oak chips are added now and also at the beginning of fermentation with the intent of stabilizing the wine color.  Adding oak at this stage does not impart oak flavor although some believe it may add tannins.

Toward the end of the cold soak, the necessary adjustments are made to the brix (sugar) and acid levels.  At the end of the 48 hours, the must’s temperature is slowly increased to +65ºF to create a warmer environment for the yeast to thrive.  Some home winemakers prefer to ferment with wild (indigenous) yeasts;  however, cultured yeasts are often used for more reliable results.

Wine yeast is proofed similarly to culinary yeasts; a warm water bath reconstitutes the dry yeast.  Then, small amounts of must are added to the bloomed yeast over 30-60 minutes to help acclimate the yeast to the must’s environment.  After a strong yeast colony is cultured, the yeast is pitched into the must.

Then it’s all about keeping the yeast happy. Fermentation can take anywhere from 5-21 days with 2-3 feedings of yeast nutrients before the fermentation reaches single digits.  Punching down the must multiple times daily to keep the cap wet is the rigour du jour. Nutrients are like vitamin pills for the yeast, keeping them strong and hungry.  The must is then inoculated with a malo-lactic (ML) bacteria which converts the wine’s harsher malo acid to softer lactic acid.  The use and timing of ML conversion is a matter of personal preference depending on the goal of the winemaker.  ML completion during fermentation or ageing can help prevent the corks from being blown off after the wine is in bottles.

Approaching dryness (the lesser amount of sugar in the wine, the dryer the wine), the must is pressed. We use two methods to squeeze the skins.







The symbolic basket press, designed by the Italians, has been used for centuries.  The must is loaded into the basket and the wine (free run) drips out the sides of the basket.  When the basket is full, wood blocks are ratcheted down on the skins, producing “pressed wine”.  More tannins are released from the pressed skins.





We also use a bladder press.  This model has a rubber bladder in the middle which can be expanded with water or compressed air.  The must is loaded into the press between the bladder and basket and then the skins are pressed against the basket.  The bladder press yields more evenly pressed wine with minimum labor.


The wine is tasted for quality assurance by the winemaker.  Winemakers smell and taste their wines periodically to monitor the wines’ progress.








The young wine goes into carboy or beer kegs with airlocks.








Alternatively, the wine is pressed into fermenters and covered with plastic sheeting.  The large bubbles under the plastic are signs of continued primary (yeast) and/or secondary (malo-lactic) fermentations. In 10-14 days, most the gross lees (sediment comprised mainly of dead yeast cells) are settled to the bottom.  The wine then is racked (siphoned) off the gross lees, into neutral or oak containers for ageing.


There are many uses for pomace (pressed grape skins). Many wineries reintroduce pomace  into their vineyards to increase the nutrients in the soil.  Some winemakers use the pomace to add acid to their garden and flower beds.  Animal farmers feed the pomace to their livestock (makes for happy cows!).  Some spas use the pomace as a body scrub.



The crew cleans out a macro bin.

Other than periodic rackings, blendings and tastings, red wine takes 18-24 months to age before bottling.  Good things take time.













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