Have you ever wondered about the process of grape growing and what happens in the vineyard at different times of the year?
Today I'm inviting you on a short journey through a year in the vineyard, to briefly explain the six basic stages that a vine undergoes during a vintage.
Budburst usually happens during the months of March and April in the Northern Hemisphere, and September and October in the Southern Hemisphere.
The buds on the vines will start to swell and eventually burst, allowing the fragile new shoots to start growing. This phase lasts around 4 weeks and generally starts as soon as the average daily temperatures exceed 10°C.
It is a very important and dangerous period for the vines as spring frosts can severely damage or even kill the new shoots, leading to reduced yields.
Early shoot and leaf growth
The young shoots grow rapidly and leaves start to appear. The initial growth spurt is fuelled by the carbohydrate stores that the vine built up during the winter dormancy phase. As soon as the leaves have matured enough, they start to provide extra growth support through photosynthesis.
Flowering and fruit set
Soon after the leaves have reached maturity, the vine starts to flower. The flowering sets (bunches) are called inflorescences. It is important for the vine to receive warmth, a lot of sunshine and little to no rain during flowering as rain and cold temperatures can disrupt the process and result in reduced yields.
Once the flowers have been pollinated, the berries start to form and this is called fruit set.
Véraison and berry ripening
After fruit set, the grapes start to grow. This phase lasts around six to eight weeks. The small, hard berries are all green in colour at the beginning, but as the grapes start to ripen they change colour - a process called véraison. Black grapes turn red, then purple as they ripen, and white grapes become translucent and then golden.
While the grapes are ripening, they swell and fill with water. The sugar and tannin levels rise, acid levels in the grapes start to drop and colour pigments and flavour compounds start to accumulate.
While the grapes are ripening, some water stress can be beneficial as this will inhibit shoot and leaf growth and promote grape ripening. If the vine has too many leaves at this stage the grower may choose to do summer pruning to ensure that the grapes receive enough sunlight to ripen fully.
Harvest happens towards the end of summer, usually starting towards the end of August until October in the Northern Hemisphere, and between March and April in the Southern Hemisphere.
The winemaker and grower will discuss the ripeness and acidity levels required for the style of wine and based on this the harvest will start earlier or later. Earlier harvests will result in higher acid levels and lower sugar levels in grapes. Grapes that are harvested late in the season will have higher sugar levels and lower levels of acidity.
Rainfall can be damaging during this time as it can cause the grapes to swell with water, diluting the flavours, and damp conditions can cause and promote rot.
Once all of the grapes have been harvested, the vines enter a period of rest. At this stage the shoots become woody and are known as canes. The leaves fall off and the vines start to store the extra carbohydrates in their roots in preparation for the next growing season.
During this time winter pruning will take place to prepare the vines for the next vintage. In regions where winters are extremely cold, winter freeze can kill new buds and in extreme cases even the vine itself. Growers may choose to cover parts of the vine with earth to protect against this.
Then, as soon as temperatures begin to rise, the cycle starts anew.
I hope that you have enjoyed this quick guide to the vineyard cycle. Thank you for reading, and if you'd like to receive a weekly blog post in your inbox, sign up to my newsletter (if you haven't already).
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