Harvest
The
time of harvest is identified following the trend of aging in post
veraison by determining the following parameters: average weight of the
bunches and berries, sugar content, pH and total acidity. Because
on the same plant, the different clusters have never the same level of
maturation, (those closest to the strain have a higher sugar content
than those that are at the end of the shoot, the more mature clusters
are located, generally more away from the ground), withdrawals are made on all parts of the plant. Given
this heterogeneity, may be conducted, at a distance of 10 days, 3-4
random sampling of sufficient quantities of 500 grape picking grapes
whole, making the average weight of berries, a few galvanized posts in the same
piece, a different exposure, because it is important
to know the situation of the plot and have an archive that allows us to
understand what is happening and predict the relationship between the
sample and the historical ones. The
optimal time of harvest is believed to be one in which the relationship
between sugar content and total acidity reaches the maximum value in
the case of sparkling wines collection tends to be early to get a wort
with an acidity of 8.5 -9 g / l, expressed as tartaric acid, while for aging wines is delayed to have a good sugar.
The
harvest is done manually severing the cluster at the base and placing
it into baskets or containers in which respect the integrity, separating
the grapes in a bad state of health, is the kind of collection more
frequent and more expensive, on average, the hourly output of a vintner is around 80-150 kg of grape harvesting. Subsequently,
the grapes are transported quickly so as to arrive in the cellar as
possible intact using potassium metabisulfite powder on the bottom of
the receptacles. Are avoided large receptacles in which the lower layers would be crushed by the weight of the upper ones. In
fact it is very important to avoid that the grapes are compressed and
crushed during shipping, because this would favor any fermentations
which are always detrimental to the quality of the product. In
case you are aiming to achieve high quality production is better to
perform the collection in boxes that preserve the integrity of most of
the clusters.
The mechanical harvesting, is very convenient if you use galvanized postes,has spread more in foreign countries, primarily in France. A
grape harvesting machine is composed of a beater apparatus which
separates the berries and can operate in either horizontal or vertical
shaking, a group of ventilation that takes away the leaves, an apparatus
spoiler product seconded and conveyors.
The
harvesters have a vertical shaking a shaker-ray that operates the
separation of the berries, working on forms of farming at GDC
The
machines are equipped with horizontal shaking auctions free or blocked
on both sides that they drop the berries are grape straddle (pass over
the trees) that operate on controspalliere. The
problems mainly concern the mechanization involves the rupture of the
berries with the subsequent release of the must, the simultaneous
presence of plant materials such as leaves and twigs, the inability to
select the clusters according to the state of aging and health, loss of
must on
the plant for leakage and soil, leaf damage by necrosis and rapid mass
transport of a more or less liquid, so the risk of fermentation is
higher than the manual harvest. The
vintage machines are to be used in vineyards and with not too pendulous
plant carattestiche appropriate, from the poles to the width of the
headland prestressed adequate.