Finishing

Question 1

Finishing

Answer 1

Preparing a wine to put in its final packaging

Question 2

Clarification

Answer 2

All ways - physical and chemical - used to make wine clear.

Question 3

Sedimentation

Answer 3

Particles of higher density than wine that forms at the bottom. This naturally forms over time.

Question 4

Centrifugation

Answer 4

A machine that comprises a rapidly rotating container using centrifugal force to separate solids from liquids. Clarifies the must quickly and are used continuously saving time and money. Disadvantage is that they are expensive and are only used in high volume wineries. Also introduces oxygen unless so2 is added.

Question 5

Fining

Answer 5

Is a procedure in which a fining agent is added to speed up the process of the precipitation of suspended material in the wine. Can be protein or mineral. It helps clarify the wine and to stabilize it again hazes in the bottle.

Question 6

Bentonite

Answer 6

A fining agent that removes unstable proteins. Bentonite is a form of clay that absorbs unstable proteins and unstable colloidal coloring matter. While it has min effect on flavor and texture of wine, it does lead to some color loss in red wines and produces large amounts of sediment so wine is lost when racked off.

Question 7

Egg White

Answer 7

A fining agent that due to its protein content, often used in fresh or powdered form. Used in high quality red wines because of its ability to remove harsh tannins and clarify wine. As an allergen it mus be shown on label in EU and other territories and is not suitable for vegan wines.

Question 8

Gelatine

Answer 8

A fining agent is a protein collagen extracted from pork that aids in clarification, removes bitterness and astringency in red wines and browning in white wine pressings. Must be used in small amounts as it can strip flavor and character and create protein hazing later. Not suitable for vegetarian or vegan.

Question 9

Casein

Answer 9

Fining agent derived from milk that removes browning from white wines and clarifies wines. Must be declared as allergen and not suitable for vegans as it is derived from milk.

Question 10

Isinglass

Answer 10

A fining agent made from protein collagen that clarifies white wines, making them appear bright. Only used in small amounts to avoid protein haze later and avoid fishy smell. Since derived from fish bladders, not suitable for vegetarian or vegan wines.

Question 11

Vegetable protein fining products

Answer 11

Fining products that are derived from potato or legumes and are suitable for vegetarian and vegan wines

Question 12

PVPP

Answer 12

Vegetable fining product - polyvinylpolyprrrolidone - is an insoluble plastic in powder form that removes browning and astringency from oxidized white wine. Rarely used on reds but can remove astringency and brighten the color.

Question 13

Charcoal

Answer 13

Fining agent that removes brown colors and some off colors. Can remove desirable aromas and flavors so care must be taken. Possibly to treat 1/2 batch with this then blend.

Question 14

Filtration

Answer 14

Is a physical separate technique to eliminate solids by passing it through a filter medium consisting of porous layers trapping the particles. Most common way of clarifying wine.

Question 15

Depth Filtration

Answer 15

Method that traps the particles in the depth of the materials that forms the filter. Can deal with wine with many particles like wines that are just pressed or with less. Doesn’t block easily but if too much pressure is applied or if filter used for too long then particles get through. Not considered an absolute filter.

Question 16

Diatomaceous earth

Answer 16

Most common form of depth filtration uses diatomaceous earth, once processed is pure silica and inert. DE is wetted and used as filter medium. Wine sucked by vacuum from the outside of rotary drum, through the DE, to the inside of the drum.

Question 17

Sheet Filters

Answer 17

AKA plate and frame or pad filters. Wine is passed through a sheet of the filtering materials. The more sheet used the quicker wine can be filtered. Sheet filters require initial investment but the sheets are relatively inexpensive.

Question 18

Surface Filtration

Answer 18

Surface filter stops particles that are bigger than the pore size of the filter from going through. Often termed absolute filters. Two types of filters, memberan and cross flow filters.

Question 19

Membrane filters

Answer 19

Sometimes called cartridge filters, Slower than using depth filtration since the pores are so small. Can easily get blocked as a result. Sometimes you use depth filtration first, then use this last. Often the last filtration used to make sure wine is clear and micro biologically stable. Sometimes called steril filtering but not totally accurate.

Question 20

Cross flow filters

Answer 20

AKA tangential filters. Allow wine to pass through the filter while uniquely cleaning the surface of the filter as it works. Can filter high loads of particles or less very quickly. Machines are expensive so typically used for large and/or well funded wineries.

Question 21

Stabilisation

Answer 21

Term used to refer to several winemaking interventions which is not used, could lead to undesirable effects in the finished wine (unwanted hazes, deposits in bottle, browning)

Question 22

Protein Stability

Answer 22

Fining with bentonite is the key procedure to ensure protein stability.

Question 23

Tartrate Stability

Answer 23

Tartrates (potassium and calcium) are harmless deposits of crystals that are formed in the finished wine. Can be seen as fault so winemakers try to avoid.

Question 24

Cold Stabilisation

Answer 24

Wine heads at 25 degrees c for around 8 days so crystals form before bottling. This removes potassium bitartrate not calcium bitartrate.

Question 25

Contact process

Answer 25

A quicker Stabilisation process which is more reliable than cold Stabilisation. Potassium bitartrate is added to the wine and speeds the start of the crystallization process. Wine is cooled for 1-2 hours at 32 degrees and the crystals are filtered out.

Question 26

Electrodialysis

Answer 26

A form of tartrate Stabilisation that uses a charged membrane to remove tartrate and calcium ions. High initial investment but total costs are lower than cold Stabilisation and the process uses less energy and is faster. Removes both potassium and calcium and to a smaller extent tartrate ions.

Question 27

Ion Exchange

Answer 27

A form of Stabilisation does not removes tartrates, but instead replaces potassium and calcium ions with hydrogen or sodium ions which will not drop out of solution. Not allowed in some places as sodium is viewed as unhealthy.

Question 28

CMC acid

Answer 28

Carboxymethylcellulose, cellulose is extracted from wood and prevents tartrates from developing to a visible size. Not for red wines as it reacts with tannins. Used for cheap roses and white. Cheaper than chilling and keeps wine stable for a few years.

Question 29

Microbiological stability

Answer 29

Methods to control the stability of the microbes in the wine once bottled. Residual sugar can referment in the bottle but can be avoided by removing yeast through sterile filtration. Lactic acid and brettanomyces (spoilage yeast) can activate in the bottle. Avoid this by having the wine go through ML or filter wine to make sure the bacteria is removed.

Question 30

Tartrates

Answer 30

Harmless deposits of crystals that form in the finished wine. Usually potassium bitartrates and less frequently calcium tartrate.

Question 31

Cork Taint

Answer 31

Associated with unattractive mouldy wet cardboard smell. Reduces fruit smell in wine.

Question 32

Oxidation

Answer 32

Too much oxides exposed either through winemaking process or once in bottle or container. Maybe because of faulty bottling or poor quality corks.

Question 33

Volatile Acidity

Answer 33

In all wines but large amounts create pungent smell of nail varnish or vinegar. Due to acetic acid bacteria, too little so2, and excess exposure to oxygen. Avoid by excluding damaged grapes, hygiene in winery keeping vessels topped up, careful racking, so2.

Question 34

Reduction

Answer 34

Silver like odors (onion to rotten eggs). Caused by high levels of volatile, reductive sulfur compounds. Happens when yeast is stressed, little to no oxygen from closed vessels, or when bottled with screw cap.

Question 35

Light Strike

Answer 35

Caused by UV radiation and certain wavelengths of visible light reacting with compounds in the wine to form volatile sulfur compounds giving odors such as dirty drains. Dark glasses are best to avoid.

Question 36

Brettanomyces

Answer 36

Brettanomyces yeast produces a range of off aromas including animal, spicy or farmyard smells. Low levels might be good. Once it is in a vineyard, it is hard to remove as it can carry out in wood and is difficult to clean. Keeping a winery clean, using so2, keeping ph levels low are best ways to avoid this. Can be filtered if a wine is effected by it.