THE HARVEST AND GRAPE PRESSING

HOME

Harvesting

Bringing in the Harvest at Moorlynch Vineyard

Because the different grape varieties ripen at different times, and due to the variation in the seasons, harvest time varies from year to year. Also although the number of days of actual picking will not be great (typically between 3 and 8), it can extend over 2-6 weeks. The most important criterion determining the time for harvesting is the acid level in the grapes. Too high and the wine is sharp to the taste, too low and it is flat, uninteresting, and will not keep. We like the sugar content to be as high as possible, but accept that in our climate really sweet grapes are unattainable - hence our concentration on light, dryish, fragrant still wines, and of course sparkling wine. In England potentially we can make sparkling wine which will stand equal to the best in the world. Already we are making waves, and we have only just begun! In October and November the grapes are harvested. Here the many varieties have the advantage that they do not all ripen at the same time so we can spread the workload out over at least 2 weeks, and more generally 3 - 4 weeks. Harvesting is a busy, but exciting time. The harvesters are all local, drawn from Moorlynch and the surrounding villages. They work hard, often in quite poor weather conditions, and cheerfully accept the sudden decision changes brought about by England's uncertain climate.

The grapes are cut off the vines in whole bunches, put in bins and weighed, so that we can build up our statistics on the yield of our various vine types. From the bins they are either:

• Transferred to the grape trailer. This is a device looking rather like a huge mincing machine. It holds one tonne of grapes, and the grapes are brought to the winery in it.
• Pressed as whole bunches of grapes. This is the system of pressing which must be used in the making of Sparkling Wine.

The weight of grapes picked varies quite a lot from year to year, as does the quality. This story is true for all English vineyards. However nobody in the world expects grape harvests to be completely reliable - that is what makes the business of wine production fascinating. We have always aimed at Moorlynch to keep sufficient stocks to carry us over a low year. In a good year we have got approaching 5 tonnes per acre of vines, but in a low year this has dropped to one tonne or so. An average over ten years is probably 2 - 3 tonnes. Our largest yield was 35,000 bottles of wine from some 50 tonnes of grapes.

In England we have to reconcile ourselves to the fact that we are too far north to get really ripe grapes as a normal crop - the map shows we are on the northern edge of the wine-producing areas in the northern hemisphere. However provided we use vines developed for cool climates, and restrict ourselves to making suitable wine styles (mainly white, light and dryish still or sparkling types) we can make wines the equal of any in the world. Heavier reds and whites need more ripeness obtained from a longer summer season, and are only made in England with some difficulty.

It is the development over a long season that gives the grape its unique wine-making properties. From flower to harvest is typically 14-15 weeks which enables the fruit to achieve very high sugar contents, and pick up all sorts of interesting flavours which increase the complexity of the final wine.

Pressing

The Wilmes 2 tonne pneumatic press at Moorlynch Vineyard

The press is a large machine with the stainless steel drum. This drum rotates, and inside it is a rubber bag. There is a slot all down one side, which enables the bag inside the drum to be filled with grapes, when the drum is turned to bring the slot to the top. If we are using the grape trailer this will be backed into the winery entrance, and a large pipe connected to it. The trailer has an auger in the bottom and when this is rotated by the power take-off on the tractor it pumps the grapes out of the trailer and into the press. The process of starting the juice extraction also takes place here because the grapes are lightly chopped as they leave the trailer. When the press is full (it holds nearly 2 tonne of grapes), perforated doors are put on the slot, and the press is rotated till the doors are downwards. The juice can now come out into the tray below. The actual pressing is done by pumping compressed air between the steel drum and the rubber bag, compressing the grapes. In a second part of the cycle the pressure is released and the drum rotated to redistribute (crumble) the grapes. This cycle of press and crumble is repeated automatically at increasing pressure 25 - 30 times over a couple of hours, up to a maximum pressure of 2 bar (30 psi). The residual material, called the pomace, is then tipped out and fed to the cattle - they love it!

The little sketches show how the press works. It consists of a steel cylinder with a loose inner rubber lining. The grapes are tipped into the lining via a slot in the side.

The slot is closed with doors which have perforations in them and the cylinder is rotated to bring the doors to the bottom. Compressed air is then pumped into the space between the steel cylinder and the liner to squeeze out the juice into the tray below.

After a couple of minutes the pressing is stopped and the press rotated to redistribute (crumble) the grapes.

The cycle of pressing and crumbling is repeated about 20 times, and finally the residue (pommace) is emptied out and carted away. The juice is pumped to a fermentation tank, and the wine making begins.

RETURN TO GRAPE GROWING OR GO TO WINE MAKING