Air Lock

Fitted to the top of the fermentation vessel. Designed to allow CO2 to escape while preventing exposure to outside air. Usually fitted to vessel with a grommet and filled with water to provide a tight seal.

Campden Tablets

Tablets used in winemaking to sterilize fermentation media (must or wine). Contains potassium metabisulfite K2S2O5 which produces sulfur dioxide SO2. Used to prepare must for fermentation (by killing off competition). Used also in combination with other additives to stop fermentation.


A French term that means “semi-dry” and indicates a wine that is neither dry nor sweet, but more dry than sweet. Wine is perceived as demi-sec when its specific gravity is in the range of 1.000 – 1.003.


A protein molecule produced by a living organism (including yeast) used as catalysts in biochemical reactions.


An enzyme that catalyzes the breakdown of pectin to pectic acid and methanol.


Describes the process by which yeasts convert sugars to alcohol.

Fermentation Vessels

Vessels in which the fermentation takes place.

Primary Fermentor

A large open mouthed container in which the ingredients are placed and fermentation begins. The large open mouth allows the yeast greater exposure to air. The vessel should be at least 20% larger than the volume of the ingredients placed within it to accommodate the yeast, which will foam and expand during fermentation. The liquids are transferred from the primary fermentor to a secondary fermentor once about 70% of the fermentation is complete.

Secondary Fermentor

A small mouthed vessel, typically a jug or a carboy, in which the ingredients are placed after primary fermentation is complete.

What type of material?

Generally recommended to use Glass for long term fermentation > 90 days. But not sure why this is.
Last modified: April 7, 2022