The grapes are grown now what?
Ripen grapes are harvested when they achieved the desired degree of brix. Brix (pronounced bricks) is a scale measuring the total dissolved compounds (concentration of grape sugars) in grape juice. The balance of acids and sugar levels at harvest corresponds to the quality of wine produced. Grapes are picked when the ratio of .9% acid to 22 brix is reached for most white wines. For those inquiring minds 2 brix of sugar corresponds to approximately 1% of alcohol in the finished wine product.
Vinification: the practical art of transforming grapes into wine.
Crushing: Roll up your pants legs and start stomping; modern technology has replaced this primitive method with machines that are designed to breaks open the grape berries so the juice is more readily available to the yeast during fermentation. Stemmers: And additional step occurring with the crush for grapes destined to make white wine whereby the stems are removed. The product generated from crushing is referred to as the must.
Maceration: This step occurs when producing red wine (the time the juice is macerated will be shorter for Rose wine). The must is allowed to mingle with the grape juice (and you thought the party started when you opened a bottle of wine). The must is kneaded or poured over the grape juice till the desired colour, tannins and flavour is soaked up. Fermentation also begins here for red wine. In Carbonic Maceration the grape berries are left whole and fermentation begin inside each berry without the assistance of yeast, it produces a light and fruity flavour with red fruit aromas, a typical production method for Beaujolais in Burgundy France.
Sulphur Dioxide (SO2): Addition of sulphur dioxide aids in inhibiting or killing bacteria and wild yeasts. This technique is used by 99% of winemakers and is regulated to maintain safe and acceptable levels. All wines naturally have Sulphites as it is a by-product of fermentation. Sensitivities and allergies have resulted in compulsory labelling information, stating if the wine contains added sulphites or preservative 220. If you have said or have heard someone saying, wine gives me a headache, I would strongly recommend reducing your consumption, rather than drink 3 glasses of wine have one of wine and two of water. Dehydration often plays a huge role in how you feel the next day, for those with sulphite sensitivities try organic wines, they shy from the standard procedure of using the addition of SO2, however as said it does occur naturally and total avoidance therefore is impossible.
Press: This process removes the skins, seeds and stems producing free-run juice. The skins can be further pressed to make pressed-juice. Winemakers may blend the two pressed juices together to add flavours and tannins, a common practice when making red wine. The pomace is the debris left over after the collection of juices; white grape pomace is used to make pomace brandy such as Grappa. No offense to Grappa lovers, however I for one favor the winemaker who returns the pomace to the vineyard for fertilization purposes.
Fermentation: The first fermentation is referred to as alcoholic fermentation; yeast is added and reacts with the grape sugars to produce alcohol and carbon dioxide (CO2) and heat. The process is done in specialized fermentation vats that regulate the temperature and vents off the CO2 without drawing in oxygen. Malolactic fermentation takes place after alcoholic fermentation; almost all reds undergo malo fermentation for increase stability. At harvest the grapes have high levels of tart malic acid (like green apples), winemakers will allow the naturally present lactic acid bacteria to convert the malic acid to the softer lactic acid. This process gives the wine a rich buttery flavour.
Lees: Is the sediment that settles at the bottom of the fermentation vessels. Less are made up of dead yeast cells, grape skin, and seeds and stem fragment and insoluble tartrates. Sur Lie a French term for aging wine on the lees, the lees contact also encourages Malolactic fermentation. Racking the wine removes wine from the lees (much like decanting).
Maturation: Historically wine was aged in barrels. Depending on the source of the barrels and how they were made can add flavors of cedar, vanilla, clove or coconut to the wine. Today wine-makers can also choose to use stainless steel tanks or cement vats that allow the wines to remain oak free bringing out the crispness of the fruit flavours.
Fining: Fining is a wine-making process use to clarify and stabilize the wine with the use of fining agents, Bentonite clay, Casein, Charcoal, and Gelatin are common agents used today. After fining the wine is filtered and ready for bottling.
Bottling and ageing: Contrary to popular belief only a small subgroup of wines benefit from bottle ageing, the majority of wine is made to be drunk within two years of being bottled. So stop procrastinating and go ahead and open that wine.
Cheers from,
The Fermented Sister