Ch 13 General Winemaking Options Flashcards

Question

# General winemaking options How does QSP affect sorting decisions?

Answer 1

○ Amount and level of sorting needs to be considered relative to expected return ○ More sorting = higher cost due to labor and time -> greater scrutiny often means lower yield ○ Poor years/cool climate - more sorting may be req to remove moldy/under-ripe fruit ○ Good years - sorting may only need to remove MOG ○ Inexpensive wines - may not be sorted at all

Answer 2

○ Remove unwanted grapes/bunches before picking/during hand harvesting ○ Sort by hand on a table or vibrating belt (also removes MOG); can be before or after de-stemming ○ Optical sorting

Answer 3

§ high tech, high cost option using digital imaging and software to scan individual grapes § Scan 100 grape sample, then full load passed thru and it rejects ind grapes (and MOG) that don’t meet sample § Can be done in harvesting machine or at reception § Usually only done for premium/super-premium due to cost

Answer 4

○ Hand harvested grapes for whites and most reds are destemmed on arrival ○ Machine harvested - destemmed in vineyard already because grapes are shaken off vine § Work by means of series of blades within a rotating drum that removes grapes from stems ○ Stems contain tannin which can be extracted if left in contact with wine -> not wanted in whites and are additional to seeds/skins in reds ○ If stems not ripe, can add unwanted green flavors and bitter tannins

Answer 5

○ Whole bunch ferms for reds (Burg PN) ○ Carbonic ○ Whole bunch pressing for some whites - common in high quality sparkling

Answer 6

○ Happens at beginning of winemaking process ○ It is application of enough pressure to break grape skins and release juice making it avail for ferm ○ Different than pressing - separation of juice or wine from skin/seeds ○ Pressure gentle enough to not crush seeds -> would add bitterness ○ Traditionally done by feet, now most wineries have a combined de-stemmer/crusher -> using this means sorting can only be done at whole bunch level

Answer 7

○ The substance that is being fermented - the mixture of grape juice, pulp, skins and seeds that comes out of the crusher ○ For whites - can also be the grape juice that is fermented (after pressing and clarification - pulp, seeds and skins removed)

Answer 8

○ Whites - grapes almost always pressed to extract juice AND separate skins from juice BEFORE ferm ○ Reds - grapes usually crushed before ferm and pressed AFTER desired time on skins or at end of ferm

Answer 9

○ Whites - goal is to crush and press berries to max juice release without extracting tannins from skins/seeds and avoid too many solids ○ Reds - since pressing is usually after ferm, need to take care to not extract excessive tannin/bitterness from skins and seeds that have been softened by being in must for 5 days - 3 weeks

Answer 10

○ Pneumatic ○ Basket ○ Screw ○ Continuous Batch processing - pneumatic, basket and screw

Answer 11

○ Most popular type of press - aka air bag presses ○ Has cylindrical cage w/ a bladder that runs down side or middle of it ○ Grapes loaded into tank on one side of bladder, other side of tank filled with air inflating bladder -> grapes gently pressed against grates on side of cage separating juice from skins ○ Adv - can be programmed with diff amts of pressure, can be flushed w/ inert gas before use to protect juice/wine from oxi ○ Disadv - expensive - most common in mid to large scale wineries, batch processing req

Answer 12

○ More traditional form of press but still in use ○ Aka vertical presses/champagne presses ○ Basket is filled with grapes -> pressure applied from above -> juice runs thru holes in side of basket and collected at bottom of press. Pipe transfers juice/wine to another vessel ○ Adv - some winemakers feel these are gentler than pneumatic, ○ Disadv - not sealed, so can't be flushed with inert gas to min 02 exposure, hold smaller volume than pneumatic -> much more labor intensive, batch processing req ○ Most common to small wineries making premium wines

Answer 13

○ Similar to basket press - mounted horizontally above rectangular draining tray ○ Less gentle, so less common ○ batch processing req

Answer 14

○ Adv - can be precisely programmed - amt of pressure and length of cycle ○ Disadv - less pressure = less color/tannin extracted but also less volume of juice/wine

Answer 15

○ Allows grapes to be continually loaded into press as it works by using screw mechanism ○ Adv - faster pressing of large volumes of grapes ○ Disadv - less gentle ○ Best for high vol, inexpensive wines

Answer 16

○ Seek balance between quality of juice/wine and volume that can be made ○ Longer press cycle extends contact between skins and juice/wine which extracts more flavor and tannin

Answer 17

Solid remains of skins and seeds after pressing

Answer 18

○ **Create more balanced wine**-> especially if there's been a compromise in reaching optimal ripeness of sugar/acid/tannin/flavors Done after must clarification for whites, can also be done after fermentation 5 adjustments: Alcohol related 1. Enrichment/chaptalization 2. reduce alcohol Acid Related 3. acidification 4. de-acidifcation 5. add tannins

Answer 19

1. climate type 2. bad weather that year 3. pests/disease 4. style of wine desired

Answer 20

What is it and when done: ○ In cool climates, common to enrich must with sugar to increase alc content of final wine ○ Done either before or during ferm In EU - increase sugar by 1. **addition** - dry sugar, grape must, grape concentrate or RCGM 2. **concentration** - reverse osmosis, vacuum extraction, chilling Adding sugar - enrichment or chaptalization

Answer 21

Rectified concentrated grape must - manufactured flavorless syrup from grapes

Answer 22

○ Sugar can be beet or cane ○ In EU, allowed with limits in cooler areas; ○ in warmer areas, not allowed to add sugar except for grape concentrate or RCGM within limits ○ As temps rise, may be less need for enrichment EU regulation: ○ Split into zones that determine the level of enrichment allowed - as well as acidification/de-acidification ○ Ex - Zone A (coolest) Germany - min natural alc -8%; max enrichment +3%; max final alc if enriched 11.5% (12% reds) ○ Ex Zone CIIIb (warmest) Portugal, S Spain, etc. - min natural alc 9%; max enrich +1.5%; max final alc if enriched -13.5%

Answer 23

Amt of alc created by yeast ferm all natrually-occurring sugar in the must into alc

Answer 24

Allowed to be done either before or during fermentation ○ In practice, done when ferm is underway -> yeasts are already active and can better cope with add'l sugar

Answer 25

○ **Reverse osmosis** and **vacuum extraction** - most expensive due to machinery cost -> limit use to wines where can recoup ROI or high volume wines ○ **Cryoextraction** - freezing the must or even final wine and extracting ice from it - costs less and is more widely used In all cases, need to consider economics given there will be less wine at the end

Answer 26

○ Reduce potential alc in warmer areas (sugar can accum quickly in grapes) ○ Add water to must to reduce alc level slightly ○ Only legal in some areas - in CA - water can be used within the addition of other processing additives ○ Disadv - dilutes grapes aromas, flavors and acids ○ Can also be done by removing alc from final wine in post-ferm adjustment

Answer 27

○ Increase acidity of must in warmer areas without cooling infl -> grapes lose malic acid signif as grapes ripen; if wine not acidified can lack freshness ○ Also done to lower pH -> inc microbiological stability, inc effectiveness of S02, inc red color in red wine and enhances ability of wine to age ○ Done in most warmer areas for inexp and mid-price wines and many premium ○ Usually done by adding tartaric acid; can also add ○ Citric acid -> not allowed in EU for acidification ○ Malic acid -> less used as it can be turned into lactic acid by MLC ○ Lactic acid -> can be used if adjustments are made after MLC - tastes less harsh than other acids

Answer 28

○ Can be done before, during or after ferm ○ Most winemakers prefer before ferm starts to benefit from effects of lower pH and because its believed acid added at this point is better integrated into wine ○ Total acidity and pH can both be affected during other parts of winemaking process - MLC, tartrate stabilization -> winemaker needs to consider this in det how much to add EU Regulation: ○ Same as enrichment - by climatic zone ○ In coolest areas - only de-acidification is allowed ○ Moderate zone CI - Bordeaux, N Spain, Trentino-Alto Adige: can deacidify or acidify ○ In warmest zones - acidification is allowed ○ Winemakers not allowed to BOTH chaptalize and acidify - to prevent musts from being "stretched" by the additions

Answer 29

○ Cool climates - grapes may be picked before fully ripe = need to de-acidify must/wine ○ Consideration - need to think about final acid level taking into account lowering of acidity due to MLC ○ Add calcium carbonate (chalk) or potassium carbonate - lowers acidity by formation and precipitation of tartrates ○ Ion exchange - high tech option - signif equip expense and need to ensure legal where the wine is sold ○ EU law sets limits on de-acidification

Answer 30

○ Add powdered tannins ○ Helps clarify must, and for reds also stabilizes color of must and improves mouthfeel ○ Can be added to the must before ferm or to the wine before mat

Answer 31

○ Conversion of sugars to ethanol and CO2 by yeast in the absence of O2 (anaerobically). Also releases heat which needs to be managed ○ Sugar + yeast + O2 = ethanol + CO2 + heat

Answer 32

yeast types - ambient vs cultured yeast impact what fermentation process produces besides alc, CO2 and heat fermentation temperatures - temp ranges ferm vessels

Answer 33

What are yeast/imapct on wine: ○ Microscopic fungi that convert sugar to alc ○ Affect the flavors/aromas of wine Aerobic respiration vs ferm: ○ Initially, yeast need o2 to multiply = aerobic respiration ○ Use up 02 and they switch to fermentation Optimal conditions: ○ Viable temp range ○ Access to yeast nutrients - esp nitrogen ○ Absence of oxygen

Answer 34

Pre-cursors: - have no flavor/aroma in must - activated by yeast ○ **Thiols** - 4MMP - boxwood/gooseberry in SB ○ **Terpenes** - linalool and geraniol - floral/grapey aromas in Muscat By yeast directly: ○ **Esters** - fruity aromas/flavors - banana in carbonic wines ○ **Undesirable aromas** - some yeast strains create **reductive sulfur compounds** (rotten egg/cabbage) and **acetaldehyde** (bruised apple/paint thinner)

Answer 35

○ Volatile acidity - in normal ferm, not enough to be perceived ○ Very small amts of naturally occurring SO2 ○ Wine aromatics - from aroma precursors or created by yeast ○ Glycerol - increases body of wine

Answer 36

○ Saccharomyces cerevisiae ○ **Reliably ferments to dryness** -> it can withstand high acidity and inc alc levels of must as it ferments ○ Also resistant to S02

Answer 37

○ O2 needed at start of ferm process to enable yeast to multiply rapidly ○ Can add yeast nutrients - esp N if levels in must are low ○ Low N -> stress the yeast and cause them to create reductive sulfur compounds (rotten egg) and/or to stop fermenting ○ DAP (Diammonium phosphate) or thiamine (B1) can be added as nutrients

Answer 38

○ Found in vineyard and in the winery ○ Includes range of yeast species - ex Kloeckera and Candida ○ Most ambients die when alc above 5% -> ○ Sacch becomes predom even in wild ferms ○ SO2 favros sacch (kills ambient) ○ ambient prefer warmer temps vs sacch advantages ○ Can add complexity to wine from several species being present, producing different aroma compounds ○ Free ○ Yeast pop in a must can be unique to place/region esp if cultured yeasts not been used ○ Can be used in marketing the wine disadvantages ○ Ferm may start slowly - dangerous for buildup of unwanted VA and growth of spoilage orgs (brett) and bacteria which can lead to off flavors ○ Ferm to dryness can take longer - may not be desirable in high vol winery ○ Risk of stuck ferm leaving wine vulnerable to spoilage orgs ○ Cant guarantee consistent product

Answer 39

* Yeast strain selected in lab and grown in volumes to sell -> often single strain of sacch * Aka selected yeast or commercial yeast How used: ○ Must may be cooled to prevent ferm from ambient yeast; or SO2 can be added ○ Starter batch made up of fermenting grape must which has been activated with cultured yeast then added to tank of must to be fermented ○ Cultured yeast that are added which quickly overwhelm natural yeast Another strain: ○ Sacch bayanus - used for must w/ high pot alc or re-ferm sparkling wine Advantages: ○ Reliable, fast ferm to dryness ○ Produce low levels of VA ○ Given speed/reliability - less risk of spoilage orgs/bacteria -> one of main reasons winemakers use cultured yeast ○ Consistent product across vintages ○ Large selection of cultured yeasts available -> can tailor to quality/style (neutral for sw; another to boost aromatics of SB) Disadv: ○ Some feel lead to similarity of fruit expression (industrial wine) ○ Adds cost

Answer 40

○ Temp related to speed of ferm and affects style of wine being made ○ Many winemakers prefer warmer (25°C) temp at beginning to get yeast estab and then adjust must temp up or down as needed

Answer 41

○ Cool 12-16°C - fresher, fruitier white wines and rose -> promote production and retention of esters ○ Mid-range 17-25°C § Reds - easy drinking fruity red wines to retain fruit aromas and for low tannin extraction § Whites - middle of range for less fruity whites; top of range for barrel ferm whites ○ Warm 26-32°C § Reds - for reds with pronounced flavor concentration and high tannins -> max extraction of color and tannins, but can lose some fruity flavors High = 35°C - ferm can slow/stop as yeast can't survive -> temp needs to be controlled

Answer 42

○ Most basic level (traditional) - ferm temp can be affected by cellar temp and adjusted by changing that temp. Sluggish ferms can move to warmer room and over-warm to cooler areas ○ Modern wineries have ferm temp control systems - water or glycol jackets on ferm vessels (or inserts) ○ Pumping over (délestage) can release also release heat

Answer 43

○ Stainless steel ○ Concrete ○ Wood

Answer 44

Stainless Steel ○ Modern standard - easy to clean, avail in large range of sizes, gives high degree of temp control ○ Neutral vessels - no flavor/aroma imparted ○ Very good at protecting from O2 ○ Most common in modern, high vol wineries due to price, hygiene and high deg of mechanization Disadv - substantial initial cost

Answer 45

○ Adv - high thermal inertia - maint even temp more efficiently than s/s ○ Smaller vessels are very expensive, but thought to set up convection currents that mix fermenting must and mix the lees during mat (natural lees stirring)

Answer 46

Adv ○ Retains heat well ○ Allows micro-oxygenation that benefits red wine ferm in oak ○ Can be re-used many times - lower long term cost Disadv ○ Hygiene care is key - pores in wood can harbor bacteria/spoilage orgs ○ Very expensive to purchase initially

Answer 47

○ Plastic - light, versatile and good for small batch ferm; but permeable to O2 and temp hard to control ○ Terracotta - used historically and in small scale today - amphorae, qvevri

Answer 48

○ Aka MLF, Malo ○ Result of lactic acid bacteria converting malic acid into lactic acid and CO2 + heat (like another form of ferm) ○ Usually happens after alc ferm and sometimes during it How happen: ○ Historically - spontaneous in spring ○ Now - can be started by adding cultured lactic acid bacteria and when optimal conditions are available

Answer 49

○ Temp - 18-22°C ○ Moderate pH level - 3.3-3.5 ○ Low TOTAL SO2

Answer 50

Conditions to prevent: ○ Temp <15°C ○ Low pH (acidic environment) ○ Moderate levels of SO2 Winemakers can § add enzyme lysozyme -> kills lactic acid bacteria § move any batch of wine undergoing MLC to another part of winery to avoid spread of lactic bacteria § Filter out lactic acid bacteria to completely prevent

Answer 51

Reds regularly go thru it Whites - winemaker choice

Answer 52

○ **Reduction in acidity and rise in pH** -> lactic acid weaker than malic; may be desirable in overly acidic wines -> results in softer/smoother wine ○ **Some color loss in reds** - only an issue in very pale red wines ○ **Greater microbial stability** -> if goes thru MLC during or after alc ferm, prevents MLC from happening later spontaneously which is undesirable § If pH of wine is high, raising pH slightly can make wine more vulnerable to spoilage orgs ○ **Modifies flavor** - slight loss of fruit flavor, addition of buttery notes (diacetyl); increases VA

Answer 53

Barrel vs tank: ○ Ability to stir lees at the same time and better integrate flavors ○ Adds work - barrels may be at different temps and so need to monitor individually Same time as alc ferm: - Inc fruity char and shortens production times -> saves money as wines can be finished and sold sooner

Answer 54

○ **Acidity, pH and tannins** can be adjusted in same ways as before ferm; winemaker should only make small adjustment post-ferm -> maintain balance of wine ○ **Removal of alc** ○ **Color **- reduce unwanted tints

Answer 55

Why done: * Make a lower alc wine (<5.5%) or adjust alc level slightly How: ○ Easiest to **add water** to must - but also dilutes flavor ○ High tech solutions: § **Reverse osmosis** - most common - form of cross-flow filtration that removes flavorless permeate of alc and water which can be distilled to remove alc, then blend back in ->equipment costly but can be rented § **Spinning cone** - device first extracts volatile aroma compounds and then removes alc; aroma compounds then blended back in to wine of desired alc level -> only economic for large vol producers § EU allows both high tech approaches, but within limits

Answer 56

○ Remove unwanted tints by fining the wine ○ When making high vol wine, can enhance color by adding very small amts of MegaPurple - grape-derived coloring agent ○ Regulated in some areas - not allowed in Ribera del Duero

Ch 13 General Winemaking Options Flashcards

(80 cards)