Harvest

Question 1

Choosing harvest date

Answer 1

Used to be rule of thumb that grapes ripened 100 days after beginning of flowering. In Europe it was often based on potential alcohol levels.

More recently decision making has changed due to: warmer climate making it easier to ripen in cool climates; better viticulture enabling ripening, focus on aroma and tannin ripeness which some consider more important than optimum sugar ripeness

Overriding factor is threat of rain at harvest. If forecast may have to choose b/n underripe grapes or hope weather will improve.. Rain in last days can dillute grapes or split with threat of gray rot.

Question 2

Measuring Ripeness

Answer 2

Ripeness can have a number of meanings; growers will measure various components to decide optimum harvest time for the style they want.

Sugar Levels: easily measured by a handheld refractometer. Most dry still wines are harvested b/n 19 and 25 Brix which converts into 11 - 15% abv

Acidity Levels: Titration can be used to calculate. pH can be read by a pH meter.

Aroma and Tannin Ripeness: usually by taste with experience

High tech means are appearing on the market which give multiple readings for sugar, acidity, various other compounds. But taste still important.

Question 3

Machine Harvesting

Answer 3

Default for inexpensive and mid-priced wine and large scale production (except where low cost labor is plentiful).

May such vineyards are established to facilitate (even row spacing, turning space at end of row, flat to low gradient land

Steps can be taken to improve the quality of machine fruit: sorting out undesirable fruit before or after harvest; using a bow-rod shaking machine (rather than older machines that beat); latest machines have optical sorters on them and can crush and SO2 white grapes immediately to prevent oxidation.

Advantages: faster and cheaper in large vineyards (can be 1/3 the cost); avoids labor shortages, can be harvested at night and kept up to 15C cooler than day picking (reduces microbial spoilage and oxidation, retains fruity aromas in whites, reduces cooling costs); timing can be optimized vs organizing labor

Disadvantages: still less gnetle than hand (grapes are shaken off stem and can rupture); not suitable for carbonic and other whole bunch needed (low phenolic whites); machine costs can be high; hard if have varieties ripening at diff times in same plot; no steep slopes or limited access; only as good as tractor operator, competition for rental equipment;

Question 4

Hand Harvesting Preferred

Answer 4

Especially preferred for premium wines. Laborers remove whole bunches by cutting stems with secateurs.

Advantages: can be selectively picked (best grapes, no rot, level of ripeness); steep or irregular slopes, mixed plantings, avoid crushing and releasing juice if using small crates.

Disadvantages: more expensive in medium to large wineries; needs reliable work force, training, and supervision; easier in daylight hours so may not be able to avoid high temps (raises chance of microbial spoilage or oxidation)

Rising labor costs and scarcity are making some traditional hand harvesters reconsider. Some larger operations may hand harvest if labor is cheap or like with co-ops that source from smaller growers.

Question 5

Hand Harvested Required

Answer 5

Premium sparkling wines made with whole bunch pressing (Champagne, most bottle fermented worldwide)

Beaujolais or other carbonically made wines

Selective harvesting; botrytis affected wine

Steep slopes; bush vines without trellising