Instruct: Given a question, retrieve relevant documents that can help answer the question.
Query: How long does cider take to ferment?
The cider is ready to drink after a three-month fermentation period, although it is more often matured in the vats for up to three years.[33]
Steps taken before fermentation might include fruit or juice blending, titratable acidity and pH measurements and sometimes adjustments, and sulfur dioxide and yeast additions.[31] Fermentation is carried out at a temperature of 4–16°C (40–60°F). This temperature would be low for most kinds of fermentation, but is beneficial for cider, as it leads to slower fermentation with less loss of delicate aromas. Fermentation can occur due to natural yeasts that are present in the must; alternately, some cider makers add cultivated strains of cider yeast, such as Saccharomyces bayanus.
Cider is produced commercially in every Canadian province except Manitoba, Newfoundland and Labrador and Saskatchewan, usually with a 5–7% alcohol content although the term is also used for some non-fermented apple juices. According to the Canadian Food and Drug Regulations, alcoholic cider is an alcoholic fermentation of apple juice that does not contain more than 13% absolute alcohol by volume (ABV) or less than 2.5% ABV.
English cider contained a drier, higher alcohol content version, using open fermentation vats and bittersweet crab apples. The French developed a sweet, low alcohol "cidre" taking advantage of the sweeter apples and the keeving process.[20] These are the roots of the standard styles we know today. Cider styles evolved based on the methods used, the apples available and local tastes. Production techniques developed, as with most technology, by trial and error. In fact, the variables were nearly too widespread to track, including: spontaneous fermentation, the type of vessels used, environmental conditions, and the apple varieties. Refinements came much later when cider became a commercial product and the process was better understood. However, since there is growing popularity in ciders, the production of specialty styles has begun to increase.[17]
Aside from carrying out the primary fermentation of cider, yeast may also play other roles in cider production. The production of sparkling cider requires a second round of fermentation, and a second yeast selection. The yeast used for the secondary fermentation in sparkling cider production serve the same purpose as the yeast used in the Champagne method of sparkling wine production: to generate carbonation and distinct aromas with a fermentation that occurs in the bottle. The yeast are selected based on critical properties, such as tolerance to high pressure, low temperature, and high ethanol concentration, as well as an ability to flocculate, which allows for riddling to remove the yeast when the fermentation has finished.[67] Some researchers have also suggested that non-Saccharomyces yeasts could be used to release additional flavor or mouthfeel compounds, as they may contain enzymes, such as β-glucosidase, β-xylosidase, or polygalacturonase, which Saccharomyces yeast may not produce.[68]
In the UK there are two broad styles of cider, determined by the types of apple available. The style associated with the east of England (East Anglia, Kent, Sussex) used surplus dessert and cooking apples and was therefore characterised by an acidic, light-bodied cider. The other style, using specific cider apple cultivars with higher tannin levels, is usually associated with the West Country, particularly Somerset, and Three Counties. Within these broad types there are also a number of more specific regional styles. The ciders of Devon were often made largely from sweets, the cultivars low in acid and tannins that typified the county's orchards. Devon cidermakers also specialised in "keeved", or "matched" cider, where fermentation was slowed to produce a naturally sweet finish, though such ciders were usually intended for the London market and a fully fermented, dry "rough" cider was preferred for home consumption. Somerset ciders, by contrast, have tended to be stronger and more tannic. Bittersweet cultivars, locally known as "Jersey" apples, were typical of Somerset, although the county's most famous apple, Kingston Black, was a mild bittersharp. The West Midland county of Gloucestershire traditionally favoured bittersharp apples, giving strong ciders with a higher bite of acidity and tannins: neighbouring Worcestershire and Herefordshire also favoured acidic cider apples, but their growers also made plantings of dual purpose apples to take advantage of markets in nearby industrial centres.
Before the development of rapid long distance transportation, regions of cider consumption generally coincided with those of cider production. As such, cider was said to be more common than wine in 12th-century Galicia[71] and certainly the idea of it was present in England by the Conquest of 1066, using crab apples: the word "Wassail" is derived from a Saxon phrase, wæs hæl": it is what would have been said by Saxons as a toast at Yuletide. Southern Italy, by contrast, though indeed possessing apples, had no tradition for cider apples at all and like its other neighbours on the Mediterranean Sea preserved the Roman tradition of apples as an ingredient for desserts, as evidenced by the frescoes at Herculaneum and Pompeii, descriptions by Classical writers and playwrights, and Apicius, whose famous cookbook does not contain a single recipe for fermenting apples but rather includes them as part of main courses, especially accompanying pork.
In Norway, cider (sider) is a naturally fermented apple juice. Pear juice is sometimes mixed with the apple to get a better fermenting process started.
Beyond the Long Ashton or English system and French system for classifying cider apples, there are other considerations for characterisation. Other measurements taken of apple varieties towards use in cider classification include pH, polyphenol composition, Yeast Assimilable Nitrogen (YAN), and soluble solid concentration (ºBrix). The sharpness of an apple is affected by pH and titratable acidity. Most cultivars must reach pH levels of around 3.3 to 3.8 to aid in the fermentation process, and additions of malic acid may be necessary if the cider apple is over this desired threshold. Soluble solids as measured in units of degrees Brix can be used to quantify the potential alcohol that a yeast can ferment from the initial juice of the cider apple. This is carefully considered in cultivars from areas where there are tax regulations on the percentage of alcohol by volume that is contained in these products. In the United States, "hard cider" legally falls between the 0.5% to 8.5% alcohol by volume tax bracket. Cideries that exceed a soluble solids level of 17 °Brix will be subject to higher tax levels that are classified under cider wine. In the United Kingdom, cider falls in two duty brackets, with a flat rate for up to 7.4% ABV, and a higher duty rate for ciders between 7.4% to 8.5% ABV. Foaming is an intricate, yet essential component that can be used to assess the overall quality of a cider and distinguish between natural and sparkling ciders. Chemically, hydrophobic polypeptides contribute to the initial foam, bubble size, the extent to which it persists, number of nucleation sites, and the froth of the foam (foam collar). These chemical compositions and parameters are quantitatively measured through metrics such as foam height, foam stability height, and stability time. The olfactory sensory profile is used to determine the specific aroma of the cider. Research is still ongoing in this field, but the aromas that contribute to the sensory perceptions of cider mainly come from the phenols 4-ethyl guaiacol and 4-ethyl phenol.
Most of the natural sugar in apples are used up in the fermentation process and are converted into alcohol, and carbon dioxide. If the fermentation goes all the way, the cider will have no perceivable residual sugar and be dry.[46] This means that the cider will not taste sweet, and might show more bitterness, or acidity. Ciders are made in many parts of Europe and in the United States and each country has different representations of cider with different flavour compounds. Keeving is a traditional method of fermentation with low amounts of nitrogen in French and English ciders that is intended to slow down the rate of fermentation in hopes of retaining high esters as well as retaining some residual sugar in the bottled cider to increase effervescence in the aging process.[47] Ciders can be back sweetened, after fermentation is complete to add a sweet taste and balance out acids, tannins, and bitterness. Natural sugar can be used but this can restart fermentation in a bottle if not filtered correctly.[47] Artificial sweeteners can be used which are non-fermentable but some of these create an aftertaste, such as saccharin or sucralose, yet some of these are known for adding off flavour compounds.[48]
Nitrogen is also very important nutrient to support yeast growth and fermentation in cider. Yeast require different forms of nitrogen to take up and use themselves so nitrogenous compounds are often added to apple juice.[52] The mixture of nitrogen-containing compounds that yeast can use are referred to as 'Yeast Assimilable Nitrogen', or YAN. Even though YAN can be added into juice before fermentation, there are other ways to affect the levels of nitrogen in the juice before pressing, like the maturity of the orchard or what type of fertilizer is used.[53] Using a fertilizer with a good amount of nitrogen will help the roots of apple trees; nitrogen fixing bacteria on the roots will be able to provide the tree with more nitrogen that will be able to make its way into the fruit.[54] A low crop load can also yield juices with more YAN than a high crop load because the nitrogen in more concentrated in the low number of apples instead of being distributed to many apples.[55] While a sufficient amount of YAN is good for the yeast and ensures fermentation of the sugars in the juice to alcohol, some cider makers may choose to limit nitrogen because it is the limiting factor.[56] When the yeast are starved for nitrogen, they stop fermenting and die off.[57] This can be desirable if cider makers prefer their cider to have some more sugar than alcohol in their cider.[58] However, limiting YAN should be done in moderation because too little nitrogen can lead to an increase in H2S production; H2S is responsible for a rotten egg-like smell.[59]
In America, fermented apple juice is called "hard cider". "Apple cider" refers to unfiltered (un-fermented) apple juice, typically pasteurized to make it shelf-stable. In New England and parts of Canada, "fresh cider" or sweet cider refers to fresh pressed apple juice; this is unlike any commercial product, and can be found at farm stands and orchards.
Pears are consumed fresh, canned, as juice, and dried. The juice can also be used in jellies and jams, usually in combination with other fruits, including berries. Fermented pear juice is called perry or pear cider and is made in a way that is similar to how cider is made from apples.
The Campaign for Real Ale (CAMRA) defines "real" cider as a product containing at least 90% fresh apple juice, with no added flavourings or colourings. Their definition prohibits the use of apple and pear concentrates, and prohibits substantial chaptalisation of the juice (adding sugar prior to fermentation) except in years when the level of natural sugar in the fruit is low. They allow the addition of sweetener for taste after fermentation, and allow limited dilution after fermentation. CAMRA states that the practice of adding a substantial amount of sugar at the fermentation stage to produce a high-alcohol (12–14% abv) beverage that is then diluted with water down to 8.5% abv or less does not conform to their definition of real cider. Some traditional cider enthusiasts consider this requirement is insufficiently strict and prefer ciders made wholly from apple juice, using apple peel as the source of yeasts.
Fermentation of ciders occurs by a very similar mechanism to the fermentation of wine. The process of alcoholic fermentation is characterized by the conversion of simple sugars into ethanol by yeasts, especially Saccharomyces cerevisiae.[29] This is because, as “Crabtree positive” yeasts, they produce ethanol even during aerobic fermentation; in contrast, Crabtree-negative yeasts produce only biomass and carbon dioxide.[29] This adaptation allows them a competitive edge in the fermentation of ciders due to their high alcohol tolerance, and because of this tolerance, it is common for ciders to be fermented to dryness, although that is not always the case. Fermentations will carry on until the yeasts run out of nutrients and can no longer metabolize, resulting in a "stuck" fermentation,[30] or the fermentation is stopped.
A non-traditional pasteurised sparkling cider, it resultantly does not fit the definition of "real cider" as defined by the Campaign for Real Ale. Where traditional cider is made with whole pressed apples fermented by the wild yeasts present on the skins, Blackthorn contains apple concentrate, sugar and sweeteners and is fermented with a controlled yeast strain.
"Wild fermentations" occur when autochthonous yeast are allowed to carry out fermentation; indigenous yeasts can spontaneously initiate fermentation without any addition of other yeast strains by the cider maker. Autochthonous yeasts are wild yeast strains that are endemic to the specific location in which a cider is produced; this is the traditional method used for cider making, and many producers feel that the strains unique to their cidery contribute a sense of terroir to their product. Wild yeast populations can be incredibly diverse and commonly include species of Saccharomyces, Candida, Pichia, Hanseniaspora and Metschnikowia.[61] Typically, the native yeast take up residence in the cidery, and can be important to the unique flavor of the product.[62] Although it was once believed that the native yeast carrying out these spontaneous fermentations also came from the orchard itself, research has shown that the microbes cultured from apples in the orchard do not align with the microbes found during the various stages of fermentation, suggesting that the sole source of native yeast is the cidery.[63] Indigenous yeast strain population dynamics are affected by climatic conditions, apple variety, geographic location, and cider making technologies used.[64] These variables cause different regions to host unique endemic yeast populations. The particular composition of endemic yeast strains and the yeast's activity during fermentation are responsible for the unique characteristics of ciders produced in certain regions.[65] Unique autochthonous yeast populations promote different compositions of volatile flavor compounds, which form distinct tastes, aromas, and mouthfeel in finished ciders.[66] Using wild yeast populations for fermentation introduces variability to the cider making process that makes it more difficult to generate multiple batches of cider that retain consistent characteristics.
In the United Kingdom the Long Ashton Research Station categorised cider apples in 1903 into four main types according to the proportion of tannins and malic acid in the fruit. For cider production it is important that the fruit contains high sugar levels which encourage fermentation and raise the final alcohol levels. Cider apples therefore often have higher sugar levels than dessert and cooking apples. It is also considered important for cider apples to contribute tannins, which add depth to the finished cider's flavour.
Cider (/ˈsaɪdər/ SY-dər) is an alcoholic beverage made from the fermented juice of apples.[1] Cider is popular in the United Kingdom, especially in the West Country, and widely available. The UK has the world's highest per capita consumption, as well as its largest cider-producing companies.[2][3][4] Cider is also popular in many Commonwealth countries, such as India, Canada, Australia,[5][6] and New Zealand.[7] Aside from the UK and its former colonies, cider is popular in other European countries including Ireland, Portugal (mainly in Minho and Madeira), France (particularly Brittany and Normandy), northern Italy (Piedmont and Friuli), and Spain (especially Asturias and the Basque Country). Central Europe also has its own types of cider with Rhineland-Palatinate and Hesse producing a particularly tart version known as Apfelwein. In the U.S. and parts of Canada, varieties of fermented cider are often called hard cider to distinguish alcoholic cider from non-alcoholic "cider" or "sweet cider", also made from apples.
Apple cider vinegar, a vinegar made from fermented apple juice, is used in salad dressings, marinades, vinaigrettes, food preservatives, and chutneys. It is made by crushing apples, then squeezing out the juice. Bacteria and yeast are added to the liquid to start the alcoholic fermentation process, which converts the sugars to alcohol. In a second fermentation step, the alcohol is converted into vinegar by acetic acid-forming bacteria ("Acetobacter" species). Acetic acid and malic acid combine to give vinegar its sour taste. Apple cider vinegar has no medicinal or nutritional value. It is 94% water, with calories and all nutrients at negligible levels.
The selection of yeast used for cider production is critical to the quality of the final product. As with other fermented beverages, like wine and beer, the strain of yeast used to carry out the alcoholic fermentation also converts precursor molecules into the odorants found in the final product. In general, two broad categories of yeast are used for cider making: commercially developed strains and wild, or autochthonous, strains. In either case, the species tend to be either Saccharomyces cerevisiae or Saccharomyces bayanus. Commercial strains are available for purchase from numerous distributors, and their characteristics are typically outlined in manuals from the companies. Selection for fermentation may be based on a yeast's ability to ferment at particular sugar concentrations, temperatures, or pH. Some producers may also select for yeasts that produce killer factors, allowing them to out-compete other yeast in the juice, or they may select yeast that contribute mouthfeel or specific aromas to the cider.[60]
A cider house is an establishment that sells alcoholic cider for consumption on the premises. Some cider houses also sell cider "to go", for consumption off the premises. A traditional cider house was often little more than a room in a farmhouse or cottage, selling locally fermented cider.
Since September 2010, HM Revenue and Customs has decreed that, to be called cider, a drink must contain at least 35% apple or pear juice and must have a pre-fermentation gravity of at least 1033 degrees. The legislation was introduced to stop cheap, high-alcohol-content drinks being called cider, thus taking advantage of the lower duty rates applied to cider.
The acids in cider play a vital role in both the cider making process and in the final flavour of a finished cider. They are present in both apples and cider, and add a sour taste and a pungent odor to these respective substances.[36] Acids also serve as a preservative in the cider since microbes grow less in lower pH environments[37] and contribute to the fermentation process.[38] Most ciders have a pH of between 3.3 and 4.1.[39] The primary acid found in apples is malic acid which accounts for around 90% of the acid content in apples.[40] Malic acid contributes to the tart and sour flavours found in cider, and typically between 4.5 and 7.5 grams of malic acid per liter of cider is preferred.[41] Malic acid is also used to determine apple ripeness for harvesting, as its concentration decreases as the fruit ripens.[42] Lactic acid is also commonly found in cider,[43] and it is mainly formed from malo-lactic fermentation, a process that converts malic acid into lactic acid. This process rounds out the flavour of the cider while reducing a lot of the acidity and producing carbon dioxide as well.[44] Other acids such as citric acid can be used to add taste after fermentation, but these acids are not typically found in high concentration in apples naturally.[45]
Even with refrigeration, raw cider will begin to become slightly carbonated within a week or so and eventually become hard cider as the fermentation process continues. Some producers use this fermentation to make hard cider; others carry it to acetification to create artisanal apple cider vinegar.