Choosing the right brewing vessel is actually very important. It is the one piece of equipment that is in contact with your kombucha the most. Therefore, has the largest potential for things going terribly wrong. I don’t mean to scare you, but there are a few vessel choices that can be incredibly harmful to both yours and the SCOBY’s health.
Pay attention. Especially to the “materials you should avoid” section.
Most people start their kombucha journey with a single gallon glass container. While this will do the trick for a while, most people look to upgrade their kombucha vessel after a few brews. Some people look for an increase in size, whereas others are wanting something better suited for continuous brewing.
Whatever your reason may be, there are a few best practices you need to be following as a few dangerous mistakes you need to be avoiding!
Hopefully, this article helps you avoid some of the disastrous mistakes and keep your brews healthy and happy.
What Makes A Good Kombucha Vessel?
Kombucha brewing vessels don’t need to be complicated. If you follow a few simple principles you will be well on your way to your first brew. These principles are:
- 1-gallon or larger
- Contains a spigot
The most important consideration for your brewing vessel is that it passes food-safe criteria. Because kombucha is so acidic, it tends to absorb harmful chemicals from its container. Therefore, every container we use must be food-grade. I’ll get into more of the materials you should avoid below.
I find that anything below 1-gallon isn’t time effective. I run out of kombucha far too soon and have to start an entirely new brew every week. I find that a 1-gallon brew can last up to 2 weeks (obviously, this depends on how much kombucha you drink.) 1-gallon is also a perfect beginner size. You can usually get away with 2-gallons for batch brewing if you are a beginner, but anything larger you may start running into issues (more on this below.)
I like my vessels to be transparent. Only because I prefer to see the health of my SCOBY and watch out for any harmful parasites.
It’s always nice if your vessel has a spigot. I explain why in the article, but it basically saves you time and is essential if you are attempting the continuous brewing method.
Finally, your vessel must have a wide mouth. Airflow is a crucial part of the brewing process and your brew runs the risk of tasting like vinegar if your mouth opening is too small.
What Vessel Size Do I Need?
The first questions we need to answer is what size of vessel you should be using. For a continuous brewing vessel, you should be using something around 2-5 gallons. Anything larger is much harder to clean and store. Additionally, the brewing methods you use become more complex when you use a container that is over 5 gallons.
Brews larger than 5 gallons suffer from inconsistent flavors and slow fermentation. It’s also notoriously difficult to provide consistent levels of oxygen or maintain a constant temperature throughout the vessel. All great reasons why homebrewers should avoid anything over 5 gallons.
If you are just starting out I recommend sticking with 1-gallon brewing vessels.
This is the most common vessel size used and will suit most recipes you find on the internet. It’s also easy to use, clean, store, and maintain. It nicely fills six 16 oz flip top bottles while still leaving you enough kombucha for your SCOBY to survive. The brewing time for kombucha is usually between 7-30 days. This means you will need enough kombucha to last you this long before your next brew.
If you find you are running out of kombucha too quickly, it’s always an easy transition to a 2-gallon vessel. If you want to use the continuous brew method you are going to want at least 2-gallons. I find this is the perfect size to get the balance between the new fermentation and the kombucha being ready for consumption.
When doing your calculations, keep in mind that the SCOBY will need at least 1/2 cup of kombucha as starter liquid for the next brew.
The Mouth Size Matters
The size of the mouth on your vessel matters for three reasons:
- Oxygen supply
- SCOBY size
- Ease of cleaning
The first stages of kombucha brewing is an aerobic process. The yeast needs plenty of oxygen while it grows and multiplies. Once the primary brew is over, you can switch to a smaller mouthed container as the oxygen supply isn’t needed.
SCOBY is roughly the size of a small plate. While it is flexible, it’s not going to fit into a small-mouthed jar. Make sure you pick a container with a mouth size of at least 4 inches (6 is preferable.) This will leave you plenty of room for you to squeeze your SCOBY into its new home.
A vessel with a 9-inch mouth will brew much faster than a brew with a 3-4 inch mouth. While it may be tempting to speed up the brewing process, faster isn’t always better. Your bacteria and yeast need to strike a balance to ensure the bacteria has enough time to digest the ethanol into the healthy acids.
Speeding up your brewing process will lead to kombucha that is very vinegary in flavor! No one wants that.
Finally, cleaning wide-mouthed vessels is always easier than small-mouthed (for obvious reasons.)
The Different Types of Vessel Materials
One of the reasons kombucha tastes so great is the healthy acids produced by the bacteria. Unfortunately, one of the side effects of these acids is the tendency for them to break down any material they come in contact with. While this can be a good thing for any of the nutrients in kombucha, it can be bad news if you are using the wrong type of material in your vessel.
The acids cause any non-foods-safe material to leach into your kombucha with potentially disastrous side effects. This will definitely be harmful to the taste of the kombucha, but it can also be harmful to your health. Let’s first discuss which contains are safe to use.
The most common kombucha vessel is a transparent glass jar. These usually have wide-mouth lids and are a fine choice for anyone looking to do batch brewing. It’s perfectly fine to use colored glass as long as it’s food-safe. Using filtered glass (like a brown beer bottle) is actually preferable if your brew is going to be sitting in direct sunlight.
You must avoid any glass container that is not food-safe!
For instance, vases or etched glassware may contain lead – which will definitely seep into your kombucha brew resulting in a serious health concern. Be careful!
I prefer clear glass because it provides me a nice view of what is going on inside. I can easily check on the health of my SCOBY and make sure there are no vinegar eels. They are also extremely easy to clean.
If you’re looking to use continuous brewing you’ll want to look for a glass container with a spigot. Avoid any beverage dispensers that are used for iced tea or juice as they are not suitable due to the poor quality of the material.
You may have seen a few metal brewing vessels on the market. They are becoming increasingly popular. However, you must avoid any metal brewing vessel that is not stainless steel. Other metals are usually not food-safe. Similar to the etched glass example above, the acidic nature of kombucha will leach toxic compounds from the metal into your brew.
Stainless steel is much more resistant to leaching (the main reason it’s the standard for food-safe in addition to the anti-corrosion properties.) This is why you’ll see it widely used in the vinegar and beer industries where they require containers that can handle low pH levels.
There are two obvious downsides to using stainless steel. For one, you can’t see how your brew is doing. This makes it hard to check on the health of the SCOBY. Additionally, it’s usually much more expensive than glass containers.
On the other hand, it’s great for brewing in direct sunlight and isn’t breakable! Just some things to consider.
Historically speaking, ceramic or porcelain brewing vessels were the most common. They were easy to create by hand and offered plenty of protection from light. They’ve become less popular in recent times, but still can be found on occasion. They are usually used for storing the kombucha after the primary brew.
Again, this is another area where you need to be careful.
Regular pottery is not food-safe.
It contains lead and other harmful chemicals that will seep into your kombucha. Avoid flowerpots or non-glazed pottery. Unless you are confident you know what you’re doing, I would recommend avoiding any handcrafted pottery altogether.
However, manufactured porcelain or ceramic vessels that are food-safe are completely fine to use. For ceramics to be food-safe, all surfaces that come into direct contact with food or drink must have smooth, unbroken glassy surfaces. This means no cracks, rough spots of texturing that water, juices or oils could penetrate. Such flaws can be havens for bacterial growth.
That being said, there is no real reason to choose ceramic over stainless steel or glass. The only difference will be aesthetic.
Unsurprisingly, plastics have found their way into kombucha brewing. Make sure any plastic you use is 100% food-safe. This usually means using a higher density, brewing-grade plastic.
Stick to grade #1 (PET or PETE) and grade #2 (HDPE) plastics only!
You will be able to see this number on the plastic itself.
You’ll want to do your research to make sure the plastic used in the vessel is legitimately food-safe. I’ve heard of some companies importing brewing vessels from overseas that don’t meet the requirements for low pH brewing.
While they aren’t necessarily environmentally friendly, plastics do make a cheap alternative to the other vessel materials on the list. They are also seethrough and are generally unbreakable. Definitely something worth considering, just make sure you are doing your research before buying. You can easily check if the plastic is food-safe by looking for the food-grade logo.
Some people have found that plastics leave unacceptable flavors in their brews. I have only used glass myself so I can’t comment personally. I’d recommend you just stick with the classic glass containers if this concerns you. The price difference isn’t worth the risk!
The final material we’ll consider is another historically popular vessel material. For similar reasons as ceramic (easy to make), they were historically popular among the first fermenters. They’re also making a come-back with some of the more advanced kombucha brewers due to the fact that they add a unique flavoring to the brew.
Similar to whiskey and wine, each different type of wood is going to produce a different flavor profile to the kombucha. Kombucha brewed from wood usually has a mellow acetic-acid flavor compared to traditional kombucha.
If you feel adventurous, toasted oak barrels are typically what is used with kombucha. These barrels are the traditional choice for wine, beer, and vinegar. Keep in mind that wine is usually fermented in stainless steel containers and is then aged in barrels.
I haven’t really heard of many people completing their primary brew in a wooden vessel. This is due to the fact that it’s difficult to find a barrel that has a big enough hole to fit the SCOBY inside! Rather, most of the barrels I’ve seen have been used to age the kombucha during the second ferment.
Materials To Avoid
While I’ve mentioned most of the materials you should avoid in the paragraphs above, I’ll write out a list just so you can be sure. Basically, you will want to avoid anything that is not food-safe. I’d like to think that every vessel on the market will be food-safe, but it’s still a good idea to double check.
Non-food-safe vessels usually come into play when people try to make their own. If this is you, do your research before you try your first brew. In general, you’ll want to avoid:
- Non-stainless steel
- Homemade pottery
If you are still unsure about your vessel material, you can always use a home lead test. This will at least cover you for any cases of lead poisoning.
Should I Buy Single Batch Or Continous Brew Vessels?
The difference between a single batch and a continuous brew (CB) vessel is the spigot. Continous brew vessels need a way for you to access the kombucha without disturbing the SCOBY floating on the top. This is where spigots come in. A spigot, if you don’t know, is a valve at the bottom of the brewing vessel that releases the kombucha whenever you need it.
Most brewers transition to continuous brewing after their first few brews. It appeals to those who wish to make a lot of kombucha at once as well as those who wish to reduce their time commitment to the process.
So, knowing most people switch to continuous brewing, should you just buy a vessel with a spigot right off the bat?
For some, this may be a good idea. The only downside is CB vessels need to be at least 2-gallons in size. They also tend to be more expensive compared to single batch vessels. The upside is CB vessels have all of the same functionality as single batch vessels. In other words, you can still bottle your kombucha if you want the extra carbonation.
If you know kombucha brewing is for you and see yourself drinking kombucha daily, then go ahead and buy a 2-gallon CB vessel. If you unsure if you will stick with it, it may be worth saving your money.
Choosing The Right Spigot For A Continous Brew Vessel
As I mentioned above, a spigot is an essential part of the CB method. Although there are ways around it, such as using a ladle, the ease-of-use of a spigot is well worth the investment. It makes bottling, sampling, and cleanup a breeze.
Unfortunately, many everyday beverage dispensers are unsafe for use with the low pH of kombucha. Lots of beginners buy an off-the-shelf beverage dispenser only to find out later that they’ve been introducing nasty toxins into their kombucha! Lots of the common spigots used on everyday dispensers use low-grade plastic, some kind of metallic paint, or some form of the materials to avoid (listed above.)
The fact of the matter is high-quality spigots can be expensive! Companies are always in a race to the bottom for the price and an easy way to cut corners is by downgrading the spigot.
The best spigots will be some form of the following:
- Uncoated or unpainted
- Made from food-safe material
- Usually made from stainless steel, wood, or food-grade plastics
- Free of glue or epoxies
- Easily removable
- Completely corrosion resistant
If the spigot cannot be easily removed, it should not be used. It’s important to be able to remove the spigot to completely clean the container to avoid mold and other contaminations. Most of the spigots I see on the market are made from cheap plastic with a chrome color paint to make them look like metal spigots. Beware! Kombucha will easily strip this paint from the spigot and you will be drinking paint flakes in no time.
I try to look for stainless steel if possible, or high-grade plastic as an alternative option. Just be prepared to pay a little extra. Wood is another perfectly fine option to consider (can also be cheaper as well.)
Does My Kombucha Vessel Need A Lid?
Yes, and no. Pesky critters love the smell of fermenting kombucha – fruit flies in particular. Therefore, we need to keep a tight barrier on the kombucha at all times. On the other hand, the primary stage of brewing requires plenty of oxygen. Therefore, we need something that is both breathable and tightly woven enough to prevent fruit flies from getting into our brew.
This rules out any lids that are screwed on. It also rules out the commonly recommended cheesecloth. I found the weave of cheesecloth is much too loose. It wasn’t able to prevent fruit flies from entering the brew and I suspect it did little for preventing other unwanted organisms (such as mold.)
I like to use a tightly woven dishcloth that is secured with an elastic band. Cheap and easy.
Some people use mason jars with the ring lids to secure fabric over top.
Remember, don’t use a tight lid! Kombucha needs plenty of airflow to brew properly.
Tight lids should only be used during the second ferment. This is when much of the carbonation is formed. It’s also where you can flavor your brew. I like using swing-top bottles. I find they are the best at keeping in the carbonation and are a breeze to use.
For most people, the best brewing vessel will be a 1-gallon glass container. This will work for 99% of the cases. If you think you’ll be drinking a lot of kombucha, you can go with a 2-gallon glass container with a spigot.
For more advanced brewers, a wood brewing vessel will be an interesting option. You can then begin to experiment with how the different wood types impact the flavoring of the kombucha.
Save the stainless steel and ceramic containers for aesthetic appeal only. In other words, if you want something that will look great in your kitchen, this material type may be your best option.
Plastics should be avoided if possible, but can still work fine if that’s all you have available to you.