We know that lots of our customers are avid wine lovers, so today we thought we would give you a brief explanation of how wine is made. Next time you’re hosting a party or tasting a new wine, you’ll be sure to impress your friends with your knowledge!
Grapes are usually harvested in late summer and autumn. Wine grapes are often harvested at night because the temperature in the day can change the sugar composition of the grapes. This might affect the fermentation process. Sparkling wine grapes are harvested first to keep the sugar levels low, followed by white wine grapes and then red wine grapes which take longer to mature.
Whilst harvesting by hand allows selection of the best grapes and can protect against damage, many large vineyards will use mechanical harvesting as it can be quicker and cost-effective.
Crushing and Pressing the Grapes
Crushing the grapes bursts the skins so that the whole grape can be exposed to fermentation. This was historically done by stomping on the grapes with your feet. Now it is usually done by pushing the grapes through a machine. The crush gets the juices of the grapes flowing and allows this to come into contact with the skins. This is essential for red and rose wines but will be avoided for white and most sparkling wines.
The pressing separates the grape juice from the rest of the grape solids. Wineries may use a pneumatic press to make the juice drain out or use the weight of the grapes themselves to cause the juice to run.
Fermentation occurs when sugars and yeast are exposed to each other and it produces alcohol in wine. Crushing the grapes allows the natural sugar found inside to combine with the yeast on the skin. It might take place in stainless steel tanks, open plastic vats or wine barrels. The temperature is closely controlled to ensure that it does not get too high and kill the yeast.
Once fermented, the wine will be clarified to make it clear. The yeast sediment will be removed and a process of fining may take place. This involves adding a substance to collect and remove all of the unwanted particles in the wine. Fining agents include gelatine, isinglass (gelatine derived from fish), egg white, casein (a dairy protein), and bentonite (a clay).
Blending and Aging
The wine will be blended from the different grape varieties required as well as different plots within the vineyard to create the blend required. Some wines may have over 100 base wines blended together. Then the wine will move into the aging stage. Only some wines will benefit from significant aging, whilst others will be better when they are still young. This depends on the variety of grapes and the conditions in which they were grown.
Winemakers may choose to age the wine in the bottle. Alternatively, barrel aging may add flavor to the wine. Oak barrels, for example, can impart vanilla flavors and a silky texture to wines.
Wine is usually poured into bottles by a machine and then sealed with a cork. The corker vacuums the air out of the bottle to remove oxygen which might otherwise break down the wine.
We hope that you have learned some more about how wine is made. Got any questions? Let us know in the comments!