Ch 9 Harvest Flashcards
Harvest
What 4 factors play into choice of machine vs hand harvesting?
○ Style, quality, price of wine
○ Logistics
○ Law
○ Costs
Harvest
What was traditional rule of thumb for when grapes ready to harvest?
How was readiness for harvest assessed traditionally - especially in EU?
100 days after beginning of flowering
Traditional way to assess readiness:
○ Potential alcohol - amount of alc that would be created by fermenting all of the sugar in the grape must into alc.
○ Cool regions - once pot alc 9.5%-11% - could harvest
Harvest
What winemaking technique can be used to adjust alc levels?
Chaptalization -adding sugar to must to inc potential alc
Harvest
What 3 factors have change timing of harvest decision in current times?
○ Warmer climates - easier to ripen grapes in cooler climates
○ Better viticulture practices - allows grapes to ripen fully
○ Focus on aroma and tannin ripeness -> often considered more impt than sugar ripeness
Harvest
What is one overriding factor that impacts harvest timing decision?
What is the implication of this decision?
What are the risks?
Threat of rain during harvest!
Implication - may have to choose bet harvesting grapes sub-optimally ripe vs risk of leaving grapes on vine hoping for better weather
Risks - dilute grapes or grape skins split and risk of rot -> can lose some/all of harvest
Harvest
How are sugar, acid and aroma/tannins assessed for ripeness?
○ Sugar - using a handheld refractometer; brix scale - most dry wines harvested at bet 19-25° brix (approx 11
-15% abv)
○ Acid - using titration; pH meter for assessing pH
§ titration - determine amt of a substance in a solution by gradually adding a measured amt of another substance that reacts in a known way
§ also by pH meter
○ **Aroma/tannins **- usually by taste
Harvest
What is brix scale?
What does 1° brix =?
Measures amount if dissolved solids in a liquid
1° brix = 1g sugar in 100g solution
9g sugar in 90g water = 10°brix = 10%
Harvest
Examples - what are harvest dates and considerations for specific styles:
- Loire Chenin
- CA Zin
- Wine with RS
- Loire Chenin
○ Harvest over 4-6 week period depending on style - early for sparkling wines; mid for dry/off dry and late for bot/late
harvest - CA Zin
○ Early to mid-Aug for white Zin; sept for reds
○ Needs care in grape selection due to uneven ripening
○ Hot areas - need to decide whether to include shriveled grapes - Wines with RS
○ Harvest late to concentrate sugars in grapes
○ Bot wines - need multiple passes for harvest
○ Icewine - grapes can only be picked when temps below certain levels (<8°C for Canada)
Harvest
What are schools of thought related to extra hang time for grapes relating to style?
○ Some feel it makes overly alcoholic wines lacking natural acidity and having extra ripe fruit char
○ Others feel these wines are awarded high scores by critics and consumers like them
Harvest
What are the 3 harvesting options?
- Machine harvesting
- Hand harvesting preferred
- Hand harvesting required
Harvest
What kind of wine is machine harvesting generally used for?
Inexpensive to mid-priced wines
Higher volume wines
New more sophisticated equipment now being used by some premium wine growers
Harvest
What can be done during vineyard establishment to optimize for machine harvesting?
○ Wide, even row spacing
○ Room for machines to turn
○ Flatter land
Harvest
What can be done to improve quality of machine harvested wines?
What is the cost impact?
○ Selecting out undesirable grapes by hand in vineyard before harvesting by machine
○ Use new, gentler “bow rod shaking” machine (vs old machines which beat vines) -> gentler and more selective
○ Newest machines have optical sorting capability, and can crush grapes and add SO2 to reduce oxidation
○ Rigorous sorting on arrival at winery - removal of MOG, unripe and rotten grapes
Harvest
What are adv (4) /disadv (7) of machine harvesting?
Advantages:
§ Signif faster and cheaper in large vineyards designed for machine harvesting; can be 1/3 cost of hand harvesting
depending on cost of labor/machines
§ Limits labor issues - lack of and reliability
§ Grapes can be harvested at night and kept up to 15°C cooler vs day harvest -> reduce spoilage and oxidation;
white wines - starting wm w/ cooler fruit preserves fresh fruit aromas; reduces refrigeration costs
§ Timing of harvest can wait until optimal ripeness and then done quickly - hand harvesting can be less flexible and
slower
Disadvantages:
§ Less gentle than hand harvesting -> grapes shaken off vine - can rupture skin and release juice; a signif
consideration for styles where whole bunches are needed and when wanting to avoid oxidation and/or extraction of
phenolic compounds - e.g. delicate whites
§ Machine rental not cost effective for smaller vy
§ May not work if growing multiple var at same time w/ diff ripening times
§ Won’t work for steep slopes/terraced
§ Quality of work only as good as machine operator
§ If vy doesn’t own harvester, can be competition from others for the machine at peak harvest moment
§ Harvesters very expensive to buy
Harvest
What is hand harvesting and when is it preferred?
What are adv/disadv?
○ Workers remove whole grape bunches from vines by cutting stem of each bunch w/ secateurs
○ Preferred when making premium wines
Advantages
§ Pickers can be highly selective in vy at bunch level; can remove diseased or under-/over-ripe fruit at havest
§ Can work on steeper slopes, irregular rows and vy w/ mixed plantings
§ Can avoid crushing of grapes (which releases juice and causes oxidation/spoilage) when handled carefully and put
in small stackable crates (max weight 10-15kilos)
Disavdantages
§ More expensive in med/large vy
§ Needs reliable workforce and training and supervision
§ Best done during day, may not avoid high temps -> inc chance of spoilage by microbes/oxidation
