Normal Kombucha Yeast Collections on Top of the Brew or Embedded in New SCOBY
As the new culture forms, sometimes a small piece of yeast will be caught just under the surface. The small yeast pocket here is definitely under the surface of some SCOBY formation, and there are no raised or dry areas, indicating a healthy brew and no Kombucha mold.
The new thin layer of Kombucha SCOBY growth allows enough light to pass through so that the dark yeast collections are visible below. While these type of yeast formations are often mistaken for Kombucha mold, they are perfectly normal.
This large collection of yeast has become completely encased in the new SCOBY growth and might be concerning for an inexperienced brewer, but this is definitely not Kombucha mold.
When first starting a new brew, sometimes very early on yeast will collect in globs along the top and edges of the brew as seen here, but no mold is present. The white foam visible mixed in with the yeast may be bubbles as a result of early fermentation or could be another type yeast replicating early on before the primary yeast and bacteria take over completely, usually by day 3 when the pH drops below 4.0.
In this wideshot, the very beginnings of SCOBY growth form first as white dots which begin to form the skin. Meanwhile, mostly at the top but also in areas around the bottom left of the photo, brown yeast clumps are collecting on the surface and may later become embedded in that SCOBY growth as it forms.
While the greenish color of this yeast collection makes it suspect at first glance, in fact is is clearly not mold due to the flat, wet appearance and the way the SCOBY is connecting over the top of the formation. Eventually the green growth will no longer be visible as white SCOBY connects completely in the new layer.
As the new layer of SCOBY forms on top of the first brew in a new Oak Barrel, it is easy to see the original 2 SOCBYs circles floating underneath the surface. Yeast strings and globs get trapped right below and small sections of SCOBY remain unformed, with the strongest areas taking shape right on top of the original cultures. All looks very healthy, no signs at all of mold. Kombucha Toasted Oak Barrel Brewing Packages
Early on in the brew, yeast will form before a new SCOBY can thicken, so these type of yeast collections under the surface are common and often cause concern. But upon closer review, this has none of the characteristics of mold, it's just normal yeast.
Coming back to the brew after 7 days or more is a great way to avoid getting freaked out about early SCOBY formation, which can look like mold. In this case, even after coming back, the green patch of yeast below the surface might look like mold to a newbie. But as we know, mold never forms below the surface, so nothing to be concerned about here.
When these type of large yeast collections poke through a thick SCOBY, they will likely stay embedded when the culture is removed from the brew. You may choose to cut out pieces of the culture or just pull them apart with clean hands. It's also fine to leave the yeast in the culture and use as is.
Here we see brown yeast pockets rising out of the white forming SCOBY growth, like submarines or wales breaching the surface. The carbonation from below combined with the lighter formation of the yeast areas in comparison to the heavier SCOBY areas creates the "inflated" look of the yeast bubbles, but all is normal, no mold.
Yeast in Kombucha are often dark in color but they can be lighter at times, and in this case early in the brew a large collection of yeast have formed a circle under the surface of the new white SCOBY just starting to form. Often this means the starter liquid had a lot of yeast or the brew is cold causing the yeast to clump together early on.
Looking down inside an oak barrel cut open wide at the top per Kombucha Kamp's specs we can see new white SCOBY growth forming across the top of the brew. The webby edges can sometimes look like wispy mold but it is the fibers of cellulose literally attaching to the barrel sides. Through the thin areas we can see the black char of the walls and some yeast, bit no mold, which is almost always fuzzy and white if it appears on the walls of barrels.
New areas of yellowish-white SCOBY formation are pictured on top of a Kombucha brew and below the surface is an area of bright yellow yeast or SCOBY. If left alone, eventually the areas of new SCOBY growth should connect into one layer that covers the bright yellow.
While this brew is not looking like it's maturing as desired, with weak SCOBY formation and a lot of yeast collecting on the surface, the part that might confuse new homebrewers is the bubbly white area. However there is nothing especially concerning about that yeast collection, beyond the other indicators that this brew may be cold or feature a weak starter.
Sometimes larger patches of yeast can be embedded in the new SCOBY growth and raised up which makes them appear to be drier or more fuzzy, but when examined closely or touched the formations are entirely below the waxy culture surface.
Close up on these yeasty pockets of tan and brown embedded in the SCOBY growth, it can appear to be dry or fuzzy to a new homebrewer. The waxy layer of new culture is covering all the formation though and only yeast is present under the ridges of fresh SCOBY coming in unevenly.
When first starting the brew, the original SCOBY may sink or float, and here it appears to have settled just below the surface. This has left the surface open for the yeast to float to the top and collect as the brew gets started. As it matures, often the yeast will drop into the liquid and disperse, or some of these collections may stay and embed in the new SCOBY growth.
When first removing SCOBYs from a long term Continuous Brew or maybe a SCOBY Hotel that has not been serviced in awhile, we might find these dense collections of yeast clinging to the bottom. No fear, they are normal! If there is so much it may throw off the balance of the new brew, it can be removed easily by hand as needed, or a layer of the SCOBY can be removed if desired. SCOBY Hotel Maintenance
A very young brew such as this Kombucha that is only 3 days old can get this kind of bump of yeast pushing up into the new SCOBY. With bubbles captured around the yeast, the culture takes on the bubbly shape which can look even more strange but just indicates some carbonation in the first ferment.
Very early in the brew it is common for a large yeast glob to appear above the original SCOBY, which floats in the brew. This brown clump is surrounded by little collections of bubbles indicating the brew is starting to progress.
This is day 6 for the brew pictured, and there is no mold present. The yeast globs and bubbles indicate some activity, but the complete lack of growth on top of the brew makes it seem like there is no bacterial
SCOBY Growth with a Large Amount of Yeast Collecting in One Corner of the Brew
SCOBY with embedded Yeast
Small Brown specs of yeast or tea in a healthy SCOBY
Thin SCOBY growth with small yeast globs attached NOT KOMBUCHA MOLD
Yeast under new SCOBY Growth
Yeast and a think layer of SCOBY attached to a thicker culture NOT MOLD on KOMBUCHA
Yeast and Bubbles embedded in new Kombucha SCOBY growth NOT MOLD ON KOMBUCHA
Yeast and Bubbles floating on top of a brand new brew with the SCOBY NOT KOMBUCHA MOLD
Yeast Bubbles and Formation But NOT MOLD B
Yeast Glob at the surface but Wet and below very thin SCOBY Growth
Yeast Glob embeds under a thin new layer of Kombucha SCOBY growth NOT MOLD ON TOP OF KOMBUCHA
Yeast Glob Looks Blue But NOT MOLD Not Fuzzy Not on Top of Brew
Yeast Glob Looks Blue Close Up But NOT MOLD Not Fuzzy Not on Top of Brew
Yeast glob on a young maybe cold Kombucha brew NOT MOLD
Yeast Glob Wet and Under the Surface NOT MOLD B
Yeast Glob Wet and Under the Surface NOT MOLD
Yeast Glob Wet and Under the Surface Wide Shot NOT MOLD
Yeast Globs Look Black and Blue But Under the Surface NOT MOLD Might Be a COLD BREW
Yeast growth in a thin SCOBY side view NOT MOLD IN KOMBUCHA