Why does the airlock have three parts?

The airlock has three components, each contributing to a healthy lactic-acid fermentation process:

Image Airlock
AMain barrel: is the airlock frame or structure, which you insert into the grommet, embedded into the Pickl-It glass lid. The barrel holds the water (1 1/2 T) which “locks” out oxygen, invasive pests and airborne yeasts, bacteria and molds so they can’t enter the fermenting chamber. We prefer this style airlock as it holds more water, is less likely to run dry, and is easier to clean than all other styles.

BFloat, aka, Valve: is placed inside the main cylinder AFTER adding approximately 1 1/2 tablespoons water. Its primary function is a “respirator”, pushed up by oxygen and excess gases “exhaled” during lacto-fermentation. Pasteur referred to lactic-acid fermentation as “respiration without oxygen”; see anaerobic

CSnap-on plastic cover: keeps the valve from being “burped” out of the airlock when a large bubble of CO2 or O2 bubbles to the surface and escapes. Small holes in the cover are the outlets for escaping oxygen, excess carbon dioxide, and other gases. It also prevents flying insects, such as fruit flies, from entering the fermentation vessel.

Tip Star The airlock is easily assembled and disassembled for cleaning or storage. Part B slides into part A, and the plastic cap, C snaps on to the top. Please make sure all three components are completely dry before placing in storage.

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Louis Pasteur

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