Enology Flashcards

Question

Please state each step in the tawny port making process

Answer 1

Harvest Grapes are sorted Grape bunches are poured into a lagar Grapes are crushed (traditionally by foot) Fermentation begins The cap is plunged for a full extraction The juice is then racked into a vat and fortified when half of the natural sugar has been consumed. The remaining skins are pressed and the juice is blended with the fortified wine. The wine is racked into oak barrels to undergo an oxidative maturation for several years.

Answer 2

``` Harvest Dry grapes for as long as 120 days Press grapes Ferment Maturation in oak vats or barrels Bottling ```

Answer 3

C6H12O6 + Yeasts = 2C2H5OH + 2CO2 + Heat

Answer 4

- Heat - CO2 - Sulfites

Answer 5

``` Malolactic fermentation (also known as MLF) is a process in winemaking in which tart-tasting malic acid, naturally present in grape must, is converted to softer-tasting lactic acid. Malolactic fermentation is most often performed as a secondary fermentation shortly after the end of the primary fermentation, but can sometimes run concurrently with it. ```

Answer 6

The process is mandatory for most red wine production

Answer 7

Between 25 and 28 Celcius

Answer 8

A 'Pied de Cuve' (starter) is made as an early start when some grapes are harvested early and left to ferment. This starter when added to the vat inoculates the new must with active yeast. Many winemakers still use this method of favoring indigenous yeast.

Answer 9

Full Control of fermentation, raise alcohol content

Answer 10

- Casein - Bentonite - Egg albumin - Gelatins - Fish proteins

Answer 11

Ullage is a winemaking term (from the French word 'ouillage') that has several meanings but most commonly refers to the gap of air between wine and the top of the container (barrel or bottle) that it is in. It can also refer to the process of evaporation that creates the gap (sometimes referred as the 'angel's share') - or it can be a past tense verb, to describe a wine barrel or bottle that has gone through the evaporation process (to be 'ullaged'). While some oxygen is beneficial to the aging process of wine, excessive amounts can lead to oxidation and other various wine faults. This is why wine in the barrels is regularly 'topped up' and refilled to the top with wine in order to minimize this gap.

Answer 12

A hydrometer is a sealed, hollow, cylindrical glass tube with weight at the bottom and a graduated scale running up the tube. 'Hollow' and 'sealed' mean that hydrometers float in liquid, and the weight at the bottom means they float sticking straight up, until the weight of the displaced liquid equals the weight of the hydrometer. This leaves the scale poking out to show you just how dense the liquid is, compared to pure water, and because sugar dissolved in liquid makes it denser, it can tell you how much sugar is in your wine kit when you start, and because alcohol dissolved in liquid makes it less dense than water, it can tell you when the fermentation is finished.

Answer 13

The presence of stems in the vat modifies the wine's make-up: - Acidity decreases - Alcohol level decreases - Tannin increases - Color remains unchanged There are nevertheless 3 advantages: - Fermentation gets underway better and is less likely to come to a stop - Rotten fruit is protected from spoilage by oxidative browning - More structure will be imparted to the wine which will increase its potential to age Note: semi-carbonic maceration is a special case where the grapes are not crushed at all.

Answer 14

Lees stirring, or bâtonnage, is the practice of stirring the sediment in the barrel, cask or tank. In the case of a barrel a curved, stainless steel, sickle-like instrument is fed into the barrel through its bung-hole before being swept back and forward to mix wine with sediment. During fermentation, yeast cells feed off grape sugar and nutrients. When fermentation stops they sink to the bottom of the tank or barrel (or bottle in the case of bottle-fermented sparkling wine). Now it’s the wine’s turn to feed off the yeasts. Lees stirring increases lees/wine contact resulting in an extra layer of brioche, yeasty flavour complexity and greater body or richness. Lees contact (amplified by stirring) encourages the release of mannoproteins, which can bind to tannins and improve the wine’s mouthfeel.

Answer 15

- Direct pressing Made using the white wine method. In fact, the method used is just like for white wine. To avoid too much color, care is needed during pressing not to break the skins too much otherwise too much pigment will leach out. A 2-step process is therefore used. 1st step: The grapes are gently pressed at low pressure which gives a pale juice which is mixed with any juice which runs out naturally. This will be the vast majority of the juice. 2nd step: The final pressing will completely dry out the pomace. This is done using higher pressure. The must which is extracted will either be vinified separately or added to a vat of red wine. Because the pressure is higher, enough pigment will escape and tint the juice. - Bleeding method/rosé de saignée The Saignée method or bleeding rosé is when during the first 24 to 48 hours of making a red wine, some of the juice is bled off and put into a new vat to make rosé. This method is very common in wine regions that make fine red wines such as Napa and Burgundy. The purpose of bleeding off the juice not only produces a lovely rosé but it also concentrates ‘the red wine-like’ intensity. Saignée wines are pretty rare, due to the production method. - Maceration The maceration method is when red wine grapes are let to rest, or macerate, in the juice for a few hours and afterward the entire batch of juice is finished into a rosé wine. The grapes are then put into a press where they are gently squeezed to extract the optimal amount of juice. The rosé juice is then placed into a stainless-steel tank and vinified similarly to a white wine. The maceration method is the most common type of rosé. - Pressage direct La méthode utilisée est identique à celle du vin blanc. Pour éviter de trop colorer, il faut faire attention lors du pressage pour ne pas trop casser les peaux sinon trop de pigments vont s'échapper. Un processus en 2 étapes est donc utilisé. 1ère étape: Les raisins sont pressés délicatement à basse pression ce qui donne un jus pâle qui se mélange à tout jus qui s'épuise naturellement. Ce sera la grande majorité du jus. 2ème étape: Le pressage final dessèche complètement le marc. Cela se fait en utilisant une pression plus élevée. Le moût extrait sera vinifié séparément ou ajouté à une cuve de vin rouge. Parce que la pression est plus élevée, suffisamment de pigment s'échappe et teinte le jus.

Answer 16

The whole grape cluster is harvested off the vine and then crushed and fermented A winemaker might choose to just throw in a few whole clusters with the rest of the destemmed grapes, or go all in with 100% whole clusters Stems impart their own unique flavors, as well as more tannins and structure. When winemakers avoid the inclusion of stems, it’s often because of the association with the “green” aromas and flavors of methoxypyrazines, which may be extracted from unripe stems.

Answer 17

``` Harvest Press Rack Ferment Blending Bottling Expedition Liquor and closure Maturation process Riddling Disgorgement Dosage Final closure Labelling ```

Answer 18

The Charmat Method - now refered to as 'Metodo Italiano' - (Italian Method), is the process where wine undergoes first or secondary fermentation in large pressurized stainless-steel tanks rather than individual bottles, and is bottled under pressure in a continuous process. The process was first studied by the Italian enologist Federico Martinotti and patented in 1907 by French winemaker Eugene Charmat. In the late 1930's the process was totally refined and completely renovated to adapt it to the Italian Prosecco - Glera grape.