Your Ultimate Guide To Kombucha Scoby

What Is Scoby Anyway?

It turns out, the term scoby is actually an acronym. It stands for “Symbiotic Culture Of Bacteria and Yeast.” Who knew!?

The acronym actually does a good job of describing exactly what scoby is. Scoby is nothing more than an active partnership between bacteria and yeast. Think of it as kind of the home where the yeast and bacteria are roommates. They feed and support each other. Both playing crucial roles in the survival of the other.

The disc-shaped glob you typically see is a byproduct of the acetic acid bacteria. As the bacteria grows, it spins cellulose into intricate structures that house both the bacteria and yeast. The yeast provides the food, while the bacteria supply the living quarters.

When the scoby is first added to a fresh batch of sweet tea, the yeast begins to break down the complex sugars into simpler forms that are easily digested by the bacteria. The first stage of the process is full of oxygen. This is when the yeast feeds the bacteria as much glucose as they can eat. In turn, the bacteria spin a new layer of cellulose that forms on top of the brew.

This new layer covers the brew and cuts down the oxygen levels from outside. Without the supply of oxygen, the yeast now moves into producing ethanol. But again, the bacteria use the by-product of the yeast to produce the acids that give the kombucha its unique taste.

As the yeast begins to wear out, it begins to form brown strands that hang off the bottom of the scoby disc. These strands eventually fall off and rest at the bottom of your container.

Finding Your First Scoby

Where you source your scoby actually makes a big difference on how your brew turns out. Different cultures of scoby are going to produce different flavor profiles ranging from sweet and tangy to downright disgusting. Even if you were to give the scoby to an experienced brewer, your kombucha will still turn out poorly.

You essentially have 3 options:

  • Buy from a supplier
  • Obtain one from a friend
  • Grow one from a commercial bottle

Buying From A Supplier

Your best option is to purchase a start scoby from a reputable seller. Many people believe that it isn’t possible to send scobys by mail, but this just isn’t true! Because we didn’t know anyone else brewing kombucha, we bought our first scoby online. As long as the seller knows what they are doing you won’t have an issue.

Won’t the temperature fluctuations ruin the scoby during transport?

Actually, scoby can survive a couple of days in cold temperatures without being harmed. So you won’t have to worry about purchasing scoby from an international supplier.

However, there are a few places you can go wrong here. You must avoid suppliers who refrigerate, freeze or dehydrate their scobys before transport. Any of these methods is going to lead to mold growing during either your first, or second brew. As I’ve mentioned before, any mold growth during the brewing process means you must throw everything out and start over.

Obtaining Scoby From A Friend

The second option I recommend is sourcing your scoby from an experienced local brewer. This is one of the best ways to ensure that your scoby is treated right and will lead to a fantastic tasting brew. Just make sure your friend is storing the scoby correctly and knows the best way to make the transfer.

The scoby should be transported in a fresh batch of matured kombucha.

If the brewer is experienced enough, you can even ask for recommendations on the different flavor qualities of each scoby batch.

Growing Your Own From A Commercial Bottle

Can you grow your own scoby from a store bought bottle of kombucha? 

This is a common question asked from new brewers. While my answer is usually no, it can be done in a pinch.

This should be a last resort option only. If you aren’t happy with any of the available suppliers and don’t know any kombucha brewers in your area, you can try and grow your own from a commercial bottle.

The issue with growing scoby from a commercial bottle is commercial producers are much more regulated compared to home brewers. This means they have to process their kombucha much more heavily than they would otherwise. For example, the alcohol levels with commercial kombucha are much more controlled.

This leads to complicated brewing processes that suck the life out of the bacteria and yeast.

Growing scoby from a commercial bottle can lead to a few successful batches, but they tend to fizzle out much faster than home-grown scoby.

If you do find yourself in this situation it’s advised to only use raw and unflavoured kombucha. Try to find a bottle that has a miniature scoby lurking at the bottom. Make sure you follow the same precautions you would with any regular scoby. In other words, use the right starter liquid and ensure that all of your storing containers and utensils are sanitized.

What A Good Scoby Should Look Like

When you first brewing kombucha, it can be hard to be confident that you are doing things right. But it’s absolutely crucial you keep an eye on your scoby during the initial stages.

If you see any sign of mold you should instantly throw out the batch and start from scratch. The tea in the jar should smell fresh, tart, and even a little vinegary (it usually becomes more pronounced the further you are in the process); if it smells rancid, or otherwise off-putting, then something has gone wrong and you should start over.

The actual shape of the scoby can vary but they typically will be a jelly-like disc shape between 1/4 and 1/2 inch thick. A scoby that is thinner than 1/4 inch indicates a weak culture whereas one that is too thick may mean it’s not getting enough oxygen.

The color should be a light tan to almost white. You can tell an older scoby by how dark it is. Newer scobys will always be much closer to white, while older scobys usually are more of a brown color.

Healthy scobys will usually have brown strings of yeast attached to the bottom. This is a healthy sign that the yeast is working hard for the bacteria and is pumping out the ethanol the bacteria needs to produce the acid and taste of the kombucha.

As a rule of thumb: Bubbles, jelly-like discs, and gritty brown-colored residue are good; black or fuzzy green spots of mold are bad.

How To Store And Take Care Of Your Scoby

So you’ve finally found yourself some scoby, how are you going to keep it from dying? There are a lot of misconceptions within the community that I will get into below, but before I do, let’s go over the right way to do things.

The first thing we need to consider is the starter liquid. The best starter liquid to use is fresh, fermented kombucha tea is taken from a previous brew. It should be around 2-4 weeks old for the best results. This kombucha should be mixed with your sweet tea. Mixing in this way will ensure your sweet tea is acidic enough to support the scoby.

This is the best chance you have of providing the scoby the exact environment it needs to flourish and grow.

Here’s what a well-aged batch of kombucha will do for you:

  • Gives the scoby a much-needed boost: well-aged kombucha is full of millions of bacteria and yeast. This gives the scoby a head start and leads to faster brews
  • Protects it from outside intruders: the pH of kombucha is low enough that outside bacteria can’t survive. This prevents any unwanted mold from attacking your scoby before it has a chance of building its own defenses
  • Provides the framework for more scoby growth: remember, the relationship between the bacteria and the yeast is one of balance. If the yeast begins to take over the brew the bacteria won’t have enough space to flourish. Setting the stage with a good batch of kombucha right off the bat will keep things in balance during the initial stages.

So you have the right liquid, but where is the best place to put it?

What Container Should I Use?

In my experience, the best solution to storing kombucha is in a clear, wide-mouth jar. There are plenty of different vessels to use, but the most common is a large glass jar (at least 1 liter). Be sure you are using only food-safe glassware (or anything else that comes in contact with your kombucha.) If you’re in a pinch you can even use an old pickle jar. With a 1 liter jar, you will need at least 1/2 cup aged kombucha and 1/2 cup room temperature sweet tea. Anything bigger will require more starter liquid.

Do I Need To Cover My Container?

Cover the glass jar with a tightly woven cloth (an old t-shirt will do.) This way, no foreign particles will invade your kombucha during the brewing process. Lots of people suggest using cheesecloth, but the fact is the weave is much too loose. This allows fruit flies, or other little particles, to enter your brew.

Do not use cheesecloth to cover your kombucha jar.

Where Should I Store The Brew?

The ideal condition is somewhere dark and warm. Keep the scoby away from anything too hot or too cold. Also, keep the scoby away from any direct sunlight. Sunlight can have an anti-bacterial effect and slow down your brewing process.

The 6 Things That Are Killing Your Scoby

There are a lot of mistakes new kombucha brewers can make when it comes to taking care of their new scoby. But it usually comes down to one of the 5 issues outlined below. Remember, you can tell if your scoby has gone bad if any mold starts to develop.


The most common mistake I see is people refrigerating their scoby. It’s such a natural inclination to refrigerate any food we may be digesting. But remember, scoby is a living organism. A few points to remember:

  • Scoby is a living organism. It likes stable, warm temperatures.
  • Cooling your scoby won’t “put it to sleep” and make it last longer. It will just weaken the bacteria’s defensives and increase the chance of mold developing.
  • Scoby can be stored in a sealed kombucha liquid for long periods of time without going bad.

If you, or the person you received the scoby from, have refrigerated the scoby for any length of time it doesn’t mean it’s the end of the world. Take the scoby out of the fridge and allow it to return to room temperature for a few days (in starter liquid of course.) Then start the brewing process as you normally would. Just be sure to pay special attention to this brew. Any sign of mold and you need to start from scratch.

Using Old Scoby

Some people are surprised when they find out that scoby actually has an age limit. While each scoby is going to be slightly different, a good rule of thumb is that scoby starts to slow down after around 5-7 brews. You may still be able to squeeze out a few batches, but the strength and quality will begin to dimish over time.

The main signal you’ll see of old scoby is in the texture. If your scoby starts to have the consistency of fruit leather, gets overly gummy or sticky– it’s past its prime and let it go. It’s difficult to tell if the scoby is old by color alone. The tannins in your teas dye the scoby and it has nothing to do with age.

Using Vinegar As A Starter Liquid

A lot of people suggest using vinegar as a substitution for aged-kombucha. While this may work in a pinch, it’s not an ideal solution. The scoby needs the boost of bacteria and yeast that is provided by the aged kombucha and sweet tea. Using plain vinegar will not supply any of the much-needed nutrients.

Vinegar may also introduce its own set of bacteria. While this may be fine, there is a chance that the different strains of bacteria won’t get along or the will compete for resources. While not common, this potentially could lead to your kombucha ending up flat and sour.

Vinegar also doesn’t have the same acidity levels as aged kombucha. This means it’s unable to act as that protective layer to the young scoby. The outside mold never had a better chance!

Using Dehyrdated Scoby

There are still some companies that will ship you dehydrated scoby. This saves them a lot of money when it comes to shipping and packaging. They also advertise that there isn’t the risk of receiving expired scoby. They couldn’t be more wrong!

As I’ve said many times before, scoby is a living organism. Like any other organism, it needs nutrients to survive. Yes, the yeast and bacteria may be forced into a hibernation state is you suddenly remove the nutrients. But you would be wrong if you thought it would bounce back completely. There is a much greater chance that your brew will develop mold (strangely, it usually happens on the second brew.)

Similar to freezing your scoby, dehydrating your scoby puts extreme stress on both the yeast and the bacteria. Even if you are able to revive them, they will have significantly reduced defenses against outside contaminants. Not to mention the brews usually taste off.

Not Enough Starter Liquid

One common mistake new brewers make is not including enough starter liquid. While they may think that the initial amount is enough, they forget to compensate for evaporation. Over time, the starter liquid will evaporate. This makes it hard for the scoby to maintain the balance it requires to flourish.

How can this happen if you are following instructions?

The issue usually arises when homebrewers forget to add additional liquid for larger batches. They will follow the recipe designed for a smaller first batch without compensating for the larger vessels. Unfortunately, I’ve seen one larger batch develop mold which sadly spread to every batch around it.

Using Commerical Starting Liquid

The kombucha found in commercial bottles is sterilized and regulated. The alcohol content is artificially reduced and different flavoring can be added post-brew. This means the bacteria and yeast are not at their optimal levels. This creates a problem because the starter liquid needs to act as an inoculant to the baby scoby.

In other words, it should provide a nutritional boost to the scoby.

You want to ensure your scoby has the best chance to thrive. The best way to do this is by providing it with the exact conditions it needs to grow and blossom. Well-aged, nutrient-rich kombucha and sweet tea is the best way to go. Not sterilized, artificially flavored, commercial kombucha.

Reusing And Sharing Your Scoby

One of my favorite things about brewing kombucha is sharing the baby scoby with anyone who is interested in starting their own brew. It’s a simple way to get to know the other brewers in your community and even make some new friends.

If you have a friend that is interested in brewing their own batch of kombucha here’s how you do it:

  1. Ensure you have a baby scoby ready from your mother. You will be able to see two separate layers on your mature scoby.
  2. Separate the top layer (called the baby) from the mother scoby. It will peel off easily.
  3. Using about half a cup of matured kombucha and half a cup of room temperature sweet tea, transfer the baby scoby into a new brewing vessel. The brewing vessel should be around 1 liter. If you are using a larger brewing vessel, you’ll want to add more starter liquid. If you don’t have a new brewing vessel, a large ziplock bag can be used instead. Just make sure your friend starts up their scoby hotel as soon as possible.
  4. If you are using a jar, make sure the top is covered with a tightly woven cloth and elastic. This prevents any contaminants from getting into the fresh brew.
  5. Return your mother scoby to the original brewing vessel. I like to use the same mix (1/2 kombucha, 1/2 sweet tea) as used for the baby scoby.

How Many Times Can I Reuse My Mother Scoby?

Opinions will vary on the lifetime of a mother scoby. I usually find my mother last for a couple of months before the brew begins to decrease in quality. As long as the mother looks healthy and continues to provide kombucha that you enjoy then there is no reason to stop using it. One consideration is older mothers tend to ferment the kombucha faster when they are in their prime.

A mother scoby can be used for at least 2 months before a new baby is required.

The best advice is to just try things out for yourself. The lifetime and quality is going to depend on a number of factors that can be different for each brewer. Let me know how long you have used a mother scoby in the comments below!

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