Flor
Encyclopedia
Winemaking
Winemaking, or vinification, is the production of wine, starting with selection of the grapes or other produce and ending with bottling the finished wine. Although most wine is made from grapes, it may also be made from other fruit or non-toxic plant material...
term referring to a film of yeast
Yeast
Yeasts are eukaryotic micro-organisms classified in the kingdom Fungi, with 1,500 species currently described estimated to be only 1% of all fungal species. Most reproduce asexually by mitosis, and many do so by an asymmetric division process called budding...
on the surface of wine
Wine
Wine is an alcoholic beverage, made of fermented fruit juice, usually from grapes. The natural chemical balance of grapes lets them ferment without the addition of sugars, acids, enzymes, or other nutrients. Grape wine is produced by fermenting crushed grapes using various types of yeast. Yeast...
and which is important in the manufacture of certain styles of sherry
Sherry
Sherry is a fortified wine made from white grapes that are grown near the town of Jerez , Spain. In Spanish, it is called vino de Jerez....
. The flor is formed naturally under certain winemaking conditions, from indigenous yeasts found in the region of Andalucía in southern Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
. Normally in winemaking, it is essential to keep young wines away from exposure to air by sealing them in airtight barrels, to avoid infection by bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
and yeasts that tend to spoil it. However, in the manufacture of sherries, the slightly porous oak barrels are deliberately filled only about five-sixths full with the young wine, leaving "the space of two fists" empty to allow the flor yeast to take form and the bung
Bung
A bung is truncated cylindrical or conical closure to seal a container, such as a bottle, tube or barrel. Unlike a lid which encloses a container from the outside without displacing the inner volume, a bung is partially inserted inside the container to act as a seal...
is not completely sealed. The flor favors cooler climates and higher humidity, so the sherries produced in the coastal Sanlúcar de Barrameda
Sanlúcar de Barrameda
Sanlúcar de Barrameda is a city in the northwest of Cádiz province, part of the autonomous community of Andalucía in southern Spain. Sanlúcar is located on the left bank at the mouth of the Guadalquivir River opposite the Doñana National Park, 52 km from the provincial capital Cádiz and...
and El Puerto de Santa María
El Puerto de Santa María
El Puerto de Santa María is a municipality located on the banks of the Guadalete River in the province of Cádiz, Spain. , the city has a population of c...
have a thicker cap of flor than those produced inland in Jerez. The yeast gives the resulting sherry its distinctive fresh taste, with residual flavors of fresh bread. Depending on the development of the wine, it may be aged entirely under the veil of flor to produce a fino
Fino
Fino is the driest and palest of the traditional varieties of sherry. They are drunk comparatively young, and unlike the sweeter varieties should be drunk soon after the bottle is opened as exposure to air can cause them to lose their flavour within hours.-Flor:The defining component of Fino...
or manzanilla
Manzanilla
Manzanilla is a variety of fino sherry made around the port of Sanlúcar de Barrameda, in the province of Cádiz, Andalusia . In Spanish, chamomile tea is called "manzanilla", and thus this wine gets the name because the wine's flavour is said to be reminiscent of such tea.The sherry is manufactured...
sherry, or it may be fortified to limit the growth of flor and undergo oxidative aging to produce an amontillado
Amontillado
Amontillado is a variety of sherry, characterized by being darker than fino but lighter than oloroso. It is named for the Montilla region of Spain, where the style originated in the 18th century, although the name 'amontillado' is sometimes used commercially as a simple measure of colour to label...
or oloroso
Oloroso
Oloroso is a variety of sherry produced by oxidative aging. It is normally darker than amontillado and has a higher glycerine content, which makes it smoother and less dry. Oloroso is usually dark and nutty....
sherry.
During the fermentation
Fermentation (wine)
The process of fermentation in wine turns grape juice into an alcoholic beverage. During fermentation, yeast interact with sugars in the juice to create ethanol, commonly known as ethyl alcohol, and carbon dioxide...
phase of sherry production the flor yeast work anaerobically
Anaerobic organism
An anaerobic organism or anaerobe is any organism that does not require oxygen for growth. It could possibly react negatively and may even die if oxygen is present...
, converting sugar into ethanol. When all the sugar has been consumed, the physiology of the yeast change to where they begin an aerobic
Aerobic organism
An aerobic organism or aerobe is an organism that can survive and grow in an oxygenated environment.Faculitative anaerobes grow and survive in an oxygenated environment and so do aerotolerant anaerobes.-Glucose:...
process of breaking down and converting the acids
Acids in wine
The acids in wine are an important component in both winemaking and the finished product of wine. They are present in both grapes and wine, having direct influences on the color, balance and taste of the wine as well as the growth and vitality of yeasts during fermentation and protecting the wine...
into other compounds such as acetaldehyde
Acetaldehyde
Acetaldehyde is an organic chemical compound with the formula CH3CHO or MeCHO. It is one of the most important aldehydes, occurring widely in nature and being produced on a large scale industrially. Acetaldehyde occurs naturally in coffee, bread, and ripe fruit, and is produced by plants as part...
. A waxy coating appears on the cells' exterior, causing the yeast to float to the surface and form a protective "blanket" thick enough to shield the wine from oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
. This process drastically lowers the acidity of the wine and makes Sherries one of the most aldehydic wines in the world. Studies have shown that for the flor to survive and thrive the wine must stay between the narrow alcohol range of 14.5 to 16% ABV
ABV
ABV is a three-letter acronym that may refer to:* Alcohol by volume, a measure of the alcohol content of alcoholic drinks* Nnamdi Azikiwe International Airport, Abuja, Nigeria, from its IATA airport code...
. Below 14.5%, the yeast do not form their protective waxy cap and the wine oxidizes to the point of becoming vinegar
Vinegar
Vinegar is a liquid substance consisting mainly of acetic acid and water, the acetic acid being produced through the fermentation of ethanol by acetic acid bacteria. Commercial vinegar is produced either by fast or slow fermentation processes. Slow methods generally are used with traditional...
. Above 16% and the flor can not survive, the wine essentially becoming an oloroso
Oloroso
Oloroso is a variety of sherry produced by oxidative aging. It is normally darker than amontillado and has a higher glycerine content, which makes it smoother and less dry. Oloroso is usually dark and nutty....
.
Other regions
A film of yeast similar to flor is also used in the production of vin jauneVin jaune
Vin jaune is a special and characteristic type of white wine made in the Jura wine region in eastern France. It is similar to dry fino Sherry and gets its character from being matured in a barrel under a film of yeast, known as the voile, on the wine's surface...
in the Jura
Jura wine
Jura wine, is French wine produced in the Jura département. Located between Burgundy and Switzerland, this cool climate wine region produces wines with some similarity to Burgundy and Swiss wine. Jura wines are distinctive and unusual wines, the most famous being vin jaune, which is made by a...
wine region in eastern France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
. The French term used for this yeast film is voile, meaning "veil
Veil
A veil is an article of clothing, worn almost exclusively by women, that is intended to cover some part of the head or face.One view is that as a religious item, it is intended to show honor to an object or space...
".
A similar yeast to flor is used in the production of Szamorodni szaraz in the Tokaj
Tokaj
Tokaj , is a historical town in Borsod-Abaúj-Zemplén county, Northern Hungary, 54 kilometers from county capital Miskolc. It is the centre of the famous Tokaj-Hegyalja wine district where the world famous Tokaji wine is produced.- History :...
wine region in northeastern Hungary
Hungary
Hungary , officially the Republic of Hungary , is a landlocked country in Central Europe. It is situated in the Carpathian Basin and is bordered by Slovakia to the north, Ukraine and Romania to the east, Serbia and Croatia to the south, Slovenia to the southwest and Austria to the west. The...
. The Hungarian name for this yeast is hártya which means film.
Natural yeast film was traditionally used in Gose
Gose
Gose is a top-fermented beer style of Leipzig, Germany.Gose beers are brewed with at least 50% of the grain bill being malted wheat. Because of the use of coriander and salt, Gose does not comply to the Reinheitsgebot. It is allowed an exemption from the rules on the grounds of being a regional...
beer to seal bottles, instead of caps or corks.