The canteiro system is named after the wooden stalks, boards on which the Madeira casks are lying in the lodges. The different types of vessels (casks or vats) ranging from 300 to 2500 litres, are aged directly under attics where the temperature can reach 25 to 30 C. The process creates additional flavors of caramel, burnt sugar, spices to the wines combined with smokiness and saltiness through a unique controlled oxidative process.
After a few years, barrels are transported to lower levels in order to slow down the evaporation and the aging process.

Other wines are aged using a system called estufagem where wines stay for a few months in a large concrete vat called estufa. It has a water heating system controlled that allows the temperature to rise slowly until reaching the mid 40s and then to decrease in a similar way. The estufa is sealed and controlled by the Madeira institute.
Depending on the grape varietal, Madeira wines are vinified dry to sweet (read our page about Madeira grapes here).
Similar to Ports, Madeira wines can be made with grapes from a single year (Vintage - Frasqueira, Colheita, Solera) or be a blend of several lots from several years.
Sweetness level in Madeira:
Dry: < 50 g. of residual sugar - Tinta Negra and Sercial
Medium Dry: 50 - 75 g. of residual sugar - Tinta Negra, Verdelho, Terrantez
Medium Sweet: 75 - 100 g. of residual sugar - Tinta Negra , Boal, Terrantez
Sweet: > 100 g. of residual sugar: Tinta Negra, Malvasia
Single Harvest Madeira - wines from a single year
Vintage Madeira - Frasqueira is made with the very best grapes from the best years from a single noble grape varietal and aged for a minimum of 20 years under the Canteiro system. It represents 0.5% of the total production of Madeira.
Colheita Madeira: If a wine doesn't reach the threshold of 20 years of cask aging, it can be released as a Colheita Madeira before becoming a Vintage. Not to be mistaken with a Colheita Port, which is a Single Harvest Tawny.
Solera: Removed from the authorised category but re-introduced in 1998. A different system from the solera system in Jerez. Not more than 10 bottlings, each time a maximum of 10% of the current wine can withdrawn and replaced by a wine from the same grape of similar quality. There are still a few bottles of Madeira solera started laet 19th century available in Funchal (Henriques & Henriques for instance).
Other wines - Blends
Corrente or 3 yo: Basic entry level Madeira wines made only with Tinta Negra and aged in Estufa. Mainly used for cooking.
Rainwater: A wine with a maximum of 10 years of age, vinified dry to medium dry, aged in estufa and lighter in color than other Madeira.
5 yo: Mostly a blend of Tinta Negra aged in estufa. A step up in quality compared to the previous category. (3 yo).
10, 15, 20, 30, 40 & 50 yo: Wines aged naturally under the canteiro system. Some producers release 10 and 15 yo made with Tinta Negra, however older blends are only made with noble grapes and are considerably more expensive. A blend must contain at least 85% of a single grape to be authorised to write the name of the grape on the label.