Sugar cane is the single fundamental ingredient of home-made grog. Introduced by the Portuguese with the beginning of the slave trade, it was only at the beginning of the 13th century that the spirit was first produced on the Island of Santo Antão. The island also appears to be the first location for the introduction of the sugar cane. The grog should be made exclusively with sugar cane, but so-called artisan producers often introduce refined sugar to the serious detriment of its quality. A national law was passed in February 2016 thanks to the work of the Confraria do Grogue di Riberira Grande, an association that has protected small artisan grog producers for years. This regulates the production and sale of aguardente de cana de açúcar and clearly details its method. The origins of the Guia de boas práticas de produção de aguardente de cana-de-açúcar, is very clear. The drink known as Grog, Grogue or Grogu, with gradation between 38 and 54 GL at temperatures of 20 degrees, must be produced exclusively from the distillation of sugar cane fermented must.
The cane is collected when it is flowering (between March and June), the leaves are removed by hand and used to feed the alembic fire or for animal forage. The canes are cut and then squashed or de-pulped by the rollers of the ""trapiche"", an electric grinder that was once animal-powered. The syrup produced, called kalda, is poured into very large wooden bins and left to ferment for 5-10 days. No raising agent is added. After fermentation it is placed in a large copper alembic, called lambiki, that holds around 200 litres, and positioned above a stone fire stocked with cane leaves, dry banana or palm leaves and different types of wood. When the steam exits from the coil, water is allowed to flow in the koxe, the conduit that permits cooling. This is the start of the distillation process. The steam condenses along the cooling tube and the distillate drips or flows slowly from the end.
Although Grog is produced along the entire archipelago, the best and most ancient production is the Island of Santo Antão.
It is a very frequently consumed drink and consumed every time guests visit. It is considered good form to drink at least two glasses.