Best Containers for Making Milk Kefir
The very first thing you will need to get your hands on when starting out to make milk kefir, is a container in which to do the ferment. This is often called a brewing vessel. Picking the right container is pretty simple, but there are some guidelines to follow, and one or two definite rules.
There are lots of different vessels you can commandeer, there is most probably one already in your kitchen. But there are also some types of containers which one really should not use.
There is a difference between milk kefir and water kefir — quite a big difference in fact. The texture of milk kefir is creamy and thick — like a liquid yogurt — while water kefir is thin like water.
As such, a container that’s IDEAL for milk kefir is not necessary the best choice for water kefir. In a pinch, you can certainly use the same container to make milk kefir as you use for water kefir. But you are better of making a distinction between the two and using slightly different equipment. Check out our article about the best containers for making water kefir if you intend to make water kefir, not milk kefir.
How to Choose the Best Container for Making (Milk) Kefir
Choosing the right container is a bit of an art and a science. It’s the single most important piece of equipment in the kefir making process. As such, you want to make the right choice.
Before we get into our actual specific recommendations, let’s talk about HOW to CHOOSE the right container.
What to Look for in the Ideal Container
- A Jar with a Wide Entrance (but not too wide): Having a jar with a wider opening and wider middle area makes it a bit easier to handle when making kefir. However, a wider jar is more important for kombucha (to fit in a good sized SCOBY) or cultured veggies (so you can put your hand in there to pack the veggies down). However, as most people may utilize the same jars for different fermented foods, it’s a good idea to buy jars that can be used for any ferment you wish. Buying a wide jar allows this. Too wide though and you increase chances of wild yeasts entering your brew — so you need to find the right balance.
- A Jar made from Non-Reactive Material: You want a jar that won’t react to the acidity of the ferment and one that won’t leak anything toxic into the brew
- A Jar with a glass, plastic, or stainless steel lid: It’s convenient having a jar with a lid. This allows you to use the same jar to store your finished kefir in the fridge if you wish. If you want to do a second ferment, you’ll need to choose a jar with a SEALED lid, such a clamped lid jar.
- A Jar that’s allows you to see the ferment: Some jars are made from different colors. However, you might want to consider using a jar that allows visibility so you can see what’s fermenting inside. This can let you ascertain, visually, how the ferment is progressing.
Best Size Container to Use for Kefir Making?
The size of container which you will need for fermenting your kefir in will depend entirely upon how much you wish to make. This in turn depends on how much you want to consume on a daily basis. Have a look at the points below to determine roughly what size you will need.
How much kefir do you want to make?
The amount of kefir you want to make will depend on how many people will be consuming it. Is it for the whole family, or just for yourself? Also, will you be using it to eat on its own, or will you be making smoothies, dips, dressings, or even kefir cheese! Even if you don’t intend to drink too much every day, you’ll find it disappears quite fast!
How much kefir do you want to drink per day?
To help you gauge what volume of kefir you should make, ask yourself how much do you want to consume per day. As kefir is best make and consumed fresh it is better to make smaller batches every day, or every two days than make a large batch for the whole week. You can use this estimate to pick out the right container size.
How long will your kefir take to ferment?
Another consideration to take into account is how long it will take your kefir to ferment. Kefir ferments fastest in warm weather. If the temperatures are low, then your kefir will take additional time to mature. Kefir does best in a temperature range of 64 to 78o Fahrenheit (17.7 to 25.5o Celsius). The usual fermentation time is around 24 hours, but you might find that 48 hours is more suitable if it is slightly cooler, and if temperatures are right at the lower end of the spectrum you might have to let it run to 72 hours.
How mature do you like your kefir?
A point to consider when determining how long your ferments will take, is how mature do you like your kefir. Most people, especially newer kefir brewers prefer their kefir on the lighter and less sour side. But if you are somebody who likes their kefir more potent, then you will have to let it ferment for longer. This means that your fermentation vessel should be larger so that it can make enough for you to consume while the next batch is fermenting.
If you are still uncertain as to how much you will want to be making –perhaps you have yet to introduce kefir to your family and are unsure how many people will be consuming it – remember you can always buy a bigger container than necessary right way, and just fill it up to the desired level. Or you can buy a few smaller containers, and split your ferments amongst them as needed.
My Kefir Brewing Vessel Size Recommendations
Kefir tastes best when it’s fresh. For the best taste, you should second ferment it or place the finished batch in the fridge for a day or two. As such, it may take you 2-4 days before you are ‘ready’ to consume your finished kefir if you give it a few days for a second ferment or aging in the fridge. This means you can do two brews per week, or if you won’t be consuming it all, one brew per week.
1/2 Gallon Vessel: I generally recommend this as the best starting size for kefir. You can brew twice a week and, if you fill up the container to the top with milk, you’ll get a maximum of about 1 gallon of kefir a week from this jar. This will keep you with 2 full cups of kefir every day with a little left over. If you don’t need so much, you can brew LESS. You can easily store 1/2 gallon jars in the fridge if you don’t want to invest in a separate storage bottle.
1 Gallon Vessel: For a smaller household. You can brew 2 gallons per week (three if you don’t do any second ferment or aging of the kefir). For most couples or families, this size will be big enough. 1 Gallon vessels are a big on the big side to fit in the fridge, so if you buy this size, plan on buying bottles for storing the kefir as well.
1.5 – 2 Gallon Vessel: For a big household with lots of kefir drinking going on. Most people won’t need this size of jar and if you do get a jar sized this big, it won’t easily fit in the fridge to store the finished product so you’ll have to invest in some bottles for storage.
Best Shape Container for Kefir Making?
There a range of different shaped containers you can use. For example, you can opt for the regular mason jar shape which typically is taller with a fairly wide open face. Or you might want to look at a pitcher style jug from which you can easily pour out the finished kefir into classes (these are best for serving kefir up). You can also opt for a shorter jar with a very wide opening which are usually offered by stoneware, porcelain containers. There is also the classic wide ‘pot’ shape that stainless steel pots.
The bottom line is that kefir is pretty flexible in how it’s brewed and you can pretty much use ANY shape vessel you wish. However,there is one thing you’ll haave to consider most:
How you are going to remove the kefir grains during the straining process
If you opt for a very large container, it’s going to be hard to strain the kefir grains out. Typically, you lift up the vessel and pour it into a strainer that sits on top of another vessel (so you need TWO containers for the straining process). If you opt for a very large container, this process is awkward and difficult and may require two people and involve a lot of mess. Opting for smaller 1/2 to 1 gallon containers makes the straining process easy to do with one person. Beyond 2 gallons, it’s not easy for one person.
Straining kefir grains can take time and some real effort, depending on how clumped up your kefir is. So it’s important to consider this.
I recommend containers that are at most about 6 inches to 12 inches tall with a medium sized opening. Your basic glass jar, for example. You can get exotic shapes that look fancy, but the more exotic the shape, the more difficult you may find to it to strain out the kefir grains. So opt for something simple.
What / How Many Kefir Containers Do You Need When Making Kefir
You can get by on ONE single container, which is used for making the kefir. But if you only have ONE container, you are going to find that’s not enough. How are you going to brew a NEW batch of kefir. What are you going to store your finished kefir in? If you plan a secondary ferment, what vessel will you use for this?
See what I mean? One single container is NOT enough for most people — not unless you brew a little bit of kefir, filter the finished kefir into a cup or bowl, drink that kefir, then brew another batch right away in the same container. This is certainly possible, but it’s tedious to do and does not account for any extra kefir to be stored or any second ferment.
We do recommend you buy a couple containers for kefir making:
- a primary ferment vessel (the largest). Having 2 gives you the option of doing two batches at once or brewing a NEW batch with the kefir grains as soon as you strain out the previous batch. We recommend having 2 of these.
- a secondary ferment vessel — IF you intend to secondary ferment. While you can use the same vessel you used to make kefir, we recommend a CLAMP style container (with a seal) for aerobic fermentation. Just a regular jar with a lid won’t seal out oxygen during the secondary fermentation process, which you want to do. We recommend having 2 to 6 of these at least.
- storage / serving container — these are nice to have for storing the finished kefir in your fridge. The primary kefir making container is likely a bit too big to easily place in the fridge and you’ll probably be wanted to keep using it for the currently fermenting kefir. That means you need another container for storing your kefir. I recommend either a pitcher style container with a lid — this makes for easy serving the chilled kefir into glasses or for placement on the table. Another option is to use the smaller EZ Cap flip top bottles (the ones for secondary fermentation) to store the kefir in the fridge. Having 2 of these containers allows for a bit of leeway with extra storage.
What Containers Not to Use
Before we get into what kind of containers make for good brewing vessels for kefir making, let’s go through what types of containers one should avoid. This is important, as using the wrong material of container could mean that you are introducing toxic substances into your kefir – which you are most probably making as an aid to good health!
Don’t Use Plastic Containers
Plastic containers, in general, are not recommended for the fermentation of kefir.
There are two reasons for this.
- Fermented and already fermenting kefir has an acidic ph. The acidity of kefir is such that it can eat away at materials which it comes into contact with. Due to the erosive nature of plastic, and the corrosive activity of acidic kefir, it is unsafe to ferment kefir in plastic containers. This is because toxins and chemicals contained within the plastic are able to leach out into your kefir! Not good.
- The second reason that plastic is an unsafe and unsuitable option as a brewing container for kefir is due to the fact that plastic scratches easily. If you are using a container which has hairline scratches on its inside, there is a possibility that these scratches might be harboring pathogenic bacteria. This bacteria could enter your ferment. While there is not a high chance of these causing you any harm, they could alter the bacterial make up of your kefir culture. This can result in fermentation problems and harm to your kefir grains.
Note: Plastic is an acceptable material for spoons, sieves, bowls and other items which you might want to use for processing your kefir once it is fully fermented. The relatively short time the plastic of these items will come into contact with your kefir will not be enough for leaching to occur. If there are any scratches on the utensils which could harbor microscopic levels of bacteria, it also will not be possible for these bacteria to enter your ferment. This is because once kefir has fully fermented, the ph will be too low for foreign bacteria to survive. Most pathogenic strains of bacteria cannot live in acidic conditions. The reason why this rule does not hold for the brewing container is because when the milk and kefir grains are added, the ph will not be acidic enough to keep out foreign bacteria. Only once fermentation gets going the ph level drops sufficiently for the ferment to be protected.
Can you use Food Grade Plastic containers to ferment?
Yes you can — the kefir will ferment just fine in it, but due to the two risks presented above, it’s not worth it when you can easily use glass. You can get away with using food grade plastic to ferment kombucha, veggies, and kefir, but it’s not ideal. Even if your food grade plastic is fine, there may be yet undiscovered byproducts of plastic leaking into your ferment. For example, it was only fairly recently that it was discovered BPA’s from plastic were toxic to human health. Glass, on the other hand, won’t have any future issues.
Don’t Use Non-Stainless Steel Metal Containers
Non-stainless steel containers are also not suitable vessels in which to ferment kefir. This once again is due to the acidity levels which fermenting kefir attains. The acidity of the kefir will react with the metal of the vessel, and some of it will leach out into your kefir. Kefir grains also do not like metal. Allowing kefir grains to come into contact with metal can harm them, and you might end up having to source a new culture! It is for this reason that one must not use metal implements, mixing bowls, sieves etc for processing your finished kefir, as even this can cause the kefir culture harm.
Don’t Use Crystal Vessels
It is also not advised to use crystal bowls and vessels to make your kefir in. This is because crystal contains lead. The possibility of lead leaching into your kefir, and you then ingesting it, is just not worth it. Lead is a toxic heavy metal, and is a health hazard if consumed.
Non Food Grade Ceramic / Ornamental Ceramic
Ceramic containers which are not coated with food grade glazing are not suitable for kefir making, as they too can be a source of lead contamination. Most ornamental types of ceramic vessels will not have a food grade glazing. But ceramic dishes which are designed for kitchen use should be glazed with an approved food grade material.
Non Food Grade Porcelain / Ornamental Porcelain
The same applies to porcelain vessels. Ornamental porcelain containers which are not covered with a food grade glazing are not safe to use as kefir making vessels, as they can too contain lead.
That about wraps it up for the unsafe types of containers to use for kefir making. If in doubt as to whether a container is safe to use, as in the case of porcelain or ceramic, it is advisable to go for one of the 100% approved options below.
Best Containers to Use for Kefir Making
So! Now that we have gotten what one cannot use out of the way – let’s get into what we can use. Remember that when it comes to size, if you are wanting to make large batches of kefir, but do not have a jar or other container big enough, you can always split your ferment across two containers.
The most common and favorite types of containers used for kefir brewing are glass vessels. I rate this as the best overall choice for Kefir making due to the wide availability o This is because glass is non reactive, and there is no danger of harmful substances leaching out into your kefir. I personally prefer glass containers for the added reason that one can look at the side of the glass, and see how well fermented you kefir is, just a glance.
Glass Mason Jars
Glass jars are great as they come in lots of different graded sizes, and they come with lids! Having a lid to screw on can be convenient if you quickly need to seal up your ferment to move it, or if you want to store the finished kefir in your fermentation vessel after it is done, minus the kefir grains. Some people also prefer to do anaerobic kefir ferments. This merely means that instead of a cloth covering, the ferment is sealed with a lid, and no air is allowed in. This division between aerobic and anaerobic fermentation is a hot topic as far as kefir making goes, but if you are wanting to try anaerobic fermenting at some point, then go for a jar with a lid. Note that some glass jars come as ‘mason jars’ which are the jars used for preserving and canning and are ideal for Kefir making, Kombucha making, or culturing veggies. You can pick up a common mason jar online for only a couple bucks.
Clamp Down Lid Glass Jar
What is even better than a normal canning lid for anaerobic fermenting is a clamp down lid with a seal. This reduces any risk of the ferment exploding as pressure builds up during fermentation. Exploding ferments can be very dangerous, not to mention a huge mess! Jars with lids which clamp down and have a rubber seal are also ideal for doing secondary fermenting. Secondary ferments are usually anaerobic, which means that having a clamp down lid for this process is great for minimizing explosion risks.
This style of jar is excellent for kefir because you can both primary ferment and secondary ferment your kefir in the same jar due to the sealed lid. It’s also good for storing your finished kefir in the fridge. As such, it’s an ‘all in one’ jar for kefir – the first ferment, second ferment, and refrigeration. The only issue is the clamp style lid that stays attached make it a bit of a pain when pouring out the kefir into another container, if you want to bottle your finished kefir. That attached lid just gets in the way and makes it awkward to hold. I’ve also found kefir can splash on the latch area, making it difficult to clean that area.
EZ Cap Lid Bottling Jar
Another good jar for second fermenting & storing your finished kefir are the EZ Cap lid. Once you’ve made your finished kefir and filtered out the grains, you can store it in the fridge or second ferment it. Either of these can be done in the EZ Cap Jar. I find second ferments are done particularly well due to the completely sealed latch and the small surface area at the top. Compared to the Clamp Down Lid Glass Jar, the EZ Cap jars make better second fermentations. This bottle is also great for second fermenting Kombucha, so having a few at hand are highly recommended.
Glass Jug / Pitcher
If you want jar for storing your finished kefir and for serving it, a jug or pitcher style jar work well. You can also do a primary ferment and use the same jar to store your finished product if you have a lid. The tapered shape and the indented channel on the top mean you can easily pour your kefir into a cup without spilling. I typically store my kefir in a pitcher / jug in the fridge and serve my kefir directly from that.
Containers which are definitely made out of food grade ceramic are fine for kefir making. I have read accounts which state that ceramic containers actually make the best tasting ferments! There is something traditional about fermenting kefir in stoneware — it just looks cool.
There is also one advantage: stoneware tends to stay more cool, so your kefir will be slightly cooler inside stoneware vs glass. Stoneware is not transparent, so the kefir is sealed away from any sunlight, though you won’t be able to keep an easy one on it because of this.
Stoneware vessels are personally my favorite container for fermenting kefir in. It makes an excellent kefir. You can also use a traditional stoneware crock to make fermented veggies, so you get a double use out of it, especially if you buy a stoneware crock with a weight and a lid (which I suggest you do).
The usual stoneware container available will likely be a stoneware crock, which will work just fine for kefir though the lid area will be quite wide.
Food Grade Porcelain
Same as above, containers which are made out of food grade porcelain are also fine for fermenting kefir in. Porcelain and Stoneware are very similar, but also different. They are both made from clay, but the process, temperature, and finish is quite a bit different. You can use food grade porcelain to make kefir. It functions about the same as stoneware. However, you need to make sure it’s food grade. Using decorative porcelain containers to make Kefir is not something you want to do as there are toxic glazes on the interior surface that will leech into the fermentation.
The only drawbacks to Stoneware and Porcelain is that
- you cannot see through the side to check quickly what your kefir is looking like. This however is not really a big deal – as you will probably start determining quickly enough how much time it takes for your kefir to ferment, even with seasonal changes in temperature.
- they are quite a bit more expensive than your regular glass jar. If you can pick up a quality glass jar for between $10 to $20, a stoneware or porcelain container will cost you between $40-$70.
Stainless Steel Pots
We generally don’t recommend stainless steel pots for Kefir making just because the containers are usually heavy and not ideally shaped for making kefir, with a very large opening area. But yes, you can use a stainless steel container (such as a beer brew container or a pot).
If you want to step up your kefir making to a semi commercial operation or you want to service a very large, very active kefir consuming household, then you might want to consider a steel pot.
You’ll be making anywhere from 2-5 gallons of kefir per brew, however, so the quantities are pretty large.
Make sure you get one with a lid — you can cover the entire surface with the lid during fermentation. Kefir can be fermented aerobically or anaerobically. The wider opening may allow for contamination of wild yeasts which can give you strange colors, flavors, and smells from the kefir. Wild yeasts won’t harm you, but they make the kefir less tasty, usually.
When using wide vessels, it’s sometimes better to put the lid on rather than using a cloth which doesn’t entirely prevent penetration of wild yeast contaminants.
Final Word on Kefir Containers
That is about it as far as guidelines and cautions go for kefir containers. The most important thing actually is to keep in mind what NOT to use, as lead, other metals, and chemicals from plastic are the last things you want in your health boosting kefir! And of course, you want a container that’s easy to lift up and pour out the finished kefir product during the kefir grain straining process.
Other than that, you can really use any glass or other fermentation safe container, and adjust as you go along, if needed, to increase or decrease the amount of kefir you need to make.
If you are not going to be doing anaerobic ferments or secondary ferments, then I would advise that you do not need clamp down jars, but merely an ordinary glass of the size of your choice. If however you are looking at anaerobic ferments, or secondary ferments – which can make your kefir taste great and have some decided health advantages – then definitely look to see if you can get your hands on some clamp down lidded jars or EZ Cap bottles.