Why Kombucha Mushrooms sink or float.

Why Kombucha Mushrooms sink or float.

Published by Ed Kasper HappyHerbalist on 1st Sep 2018

Kombucha brewers say “ hey, no worry” while Vinegar folks say “its over” “toss it” “dead”.

Even though both may utilize the exact same species of Acetobacter (bacteria) and yeasts, why the difference?

Here’s the real story.

The Kombucha Mushroom is a serendipitous colony of bacteria and yeasts. The action of their home - the mushroom results from their ebb and flow. The cellulose structure begins by the bacteria attempting to seal off oxygen from the yeasts. This serves two purposes. 1) diminishes the yeast population, and 2) forces the yeast into alcohol production - which the bacteria crave. (bacteria love sugar, caffeine and alcohol and the mushroom is their “man cave”

The same process takes place in vinegar production albeit slower. In vinegar the yeast for the most part have been eliminated. as has the sugar. Vinegar is a bacteria ferment.Produces a MOV Mother of Vinegar very similar to a SCOBY.  

For every mole of sugar the yeast expels one mole of CO2 (Carbonation) and one mole of alcohol. The yeast are also using O2 (oxygen) . O2, CO2, and alcohol are all lighter than water and become trapped in the cellulose produced by the bacteria.

The bacteria uses O2 to convert alcohol to acetic acid. Acetic acid is water soluble and dissipates out into the tea.

CO2 is Pressure and Temperature sensitive. The greater the pressure the greater the escape potential to the air above, the lower the temperature the greater the movement to dissolve in the liquid below. One would think that as the mushroom ages and the gasses deplete the mushroom will fall. However the surface tension of the mushroom supports itself on the interspace between surface and liquid. That is until it is moved or shaken about. when it may then fall below. This is the point where vinegar folks declare time of death. Since there is no more O2 or alcohol (those lighter than water attributes that keep the mushroom floating) then there is no O2 and alcohol left to convert to acetic acid (vinegar) thus the process is declared finished.

Yet Kombucha yeasts although in severe decline, a few may still be able to convert the sugar to CO2 and alcohol re-inflating the mushroom and the Kombucha mushroom may rise from “the dead” or go sideways or even appear to be escaping at times.

Once the mushroom falls, now surface O2 is available to the yeast and the yeast become more active again. The bacteria get busy building a new mushroom and the process starts over. Though now of course their is more limited resources available.

If your mushroom is laying in a velvetly field of green, or other colorful array. maybe fuzzy and hairy - then floating or sinking toss it. Check out our Kombucha Pictures online Whats Good & Whats Not 

The mushroom reflects the general health of the Kombucha Tea.

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