Normal Kombucha Yeast Floating in the Liquid and Under the SCOBY Surface
From the side it is easy to see the original SCOBY floating below the surface with small collections of light brown yeast forming in globs and strands below a row of robust bubbles. All of these factors indicate healthy, active Kombucha fermentation. See Also: 5 Signs of Healthy Kombucha. There is no mold present from this view.
Both hanging off the SCOBY at the top and forming on the SCOBYs at the bottom of the brew, these yeast collections may appear wispy like cobwebs or in heavy layers attached to the cultures, but they are never Kombucha mold.
Black blooms of normal Kombucha Yeast have formed in this brew and collected at the bottom, where they can sometimes look imposing. The good news is this is not mold, which never forms under the surface.
As this frothy Kombucha brew ferments, large collections of dark brown yeast can be seen clinging to the original SCOBY culture under the surface but also pushing up into the bubbles along the meniscus at the top of the brew. Some yeast have broken free and are floating throughout the liquid, all of which is normal for Kombucha and not mold.
Though these dark collections of yeast may look concerning to a newbie, they are perfectly normal. Some of the large pieces of yeast hanging around the top of the brew may even become lodged in the new SCOBY that grows across, which can seem like mold. However, as long as it's not dry and fuzzy on top of the new SCOBY, there is no concern.
Light, thin strands of tan yeast will form during the brewing process. The activity of the bubbles, new SCOBY growth and yeast strands show this to be a healthy brew
Because all the yeast has collected into one circular formation, it is easy to see why a new Kombucha brewer might find this intimidating. However, this is another normal yeast formation and nothing to be concerned about. These globs will mostly fall apart when the brew is disturbed, but they can also be mostly filtered out if desired. Keep in mind this may reduce flavor and carbonation, so it may be better to simply stir a yeast glob like this into the liquid at harvest time so it is distributed evenly among the bottles.
Yeast collections can take make shapes and forms and will change from brew to brew. In this case, thin ribbons of yeast have formed and extend well down the sides of the vessel. While this may look unusual, all is normal. However, we never recommend using cheese cloth, even folded over this many times, as the weave is too loose and will allow fruit flies or other contaminants in over time.
Multiple layers of Kombucha SCOBY have deeply fermented what looks like it may be a SCOBY Hotel. Appearing between each layer are some bubbles but also many smears of reddish brown yeast blooms. These collections also hang in tendrils from the bottom SCOBY layer, waving in the brew. All is normal and no mold is present in this view.
This dramatic looking curtain of brownish black yeast hangs along the edge of the Kombucha Brewing Jar, but all signs are this is a normal formation.
From the side it is easy to see the dark brown collections of yeast, but as they are under the surface they can only be yeast and not mold or any other concerning growth.
Sometimes yeast can take on the look of hair, cobwebs, flowers, spiders, or just strange blobs. In this case, a variety of yeast tendrils appear to have connected and are floating freely, bridging between the new top layer of Kombucha culture and the original SCOBY at the bottom of the brew.
It is very common for a yeast formation like the one here to occur early in the brewing process and cause concern for a new Kombucha brewer, but there is nothing to worry about as this is simply normal Kombucha yeast and not mold.
In this close up, we can see the normal Kombucha yeast collecting with bubbles inside as they push to the edge of the glass vessel. There is no mold present, just normal Kombucha yeast with a layer of SCOBY above.
Looking down on this brew we can see the yeast glob clinging to the edge and hiding under the surface of the brew with new SCOBY growth forming on top. This wet, yeast area cannot be mold as it is not above the brew and dry.
These brown collections of yeast will often form as the brew develops, hanging off each other as they connect to the new SCOBY growth on top of the liquid.
Some people refer to these as Yeast Brains, when the stringy mass folds on itself into a tubular vision that is admittedly a little unusual. Still, this is perfectly normal and definitely not mold. The thick, healthy new SCOBY growth on top is another sign of a brew progressing well, and this has probably been going for a couple of weeks at least based on the thickness.
Even though this large spread of yeast has formed between the new culture and the glass, this is a healthy brew and normal. Judging by the VERY thick layer of original SCOBY beneath, this brew may develop a bit faster than normal.
This may commonly be mistaken for mold on top of a Kombucha brew, mostly because it is a bit scary looking and it sticking up over the top of the liquid. However, it is clearly not dry and the tendrils hanging down give it away as classic Kombucha yeast mixed with white bubbles.