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When you are considering making your own kefir it is important to start with grains which will provide you with the best chance of success.
There are two types of kefir grains. Water kefir grains which ferment sweetened water into a tangy effervescent drink and milk kefir grains which ferment dairy products into a drinkable fermented yogurt like product. All kefir grains vary depending on their source and current environment.
Not only are there two types of kefir grains but the grains also vary depending on their heritage and their current environment which will have an effect on the different active bacterial species present in the grains.
The type of grains you start with depends on you
Water kefir grains are used to make water kefir from sweetened water. The grains are home to a collection of acetic acid bacteria, lactic acid bacteria and yeasts which use the sugar in the water for energy. The result is a drink which is low in sugar with a high count of probiotics increased vitamins and availability of minerals. Since it is made without milk it does not contain lactose making it the right choice if you cannot have any lactose or milk based products but still want the benefits of kefir.
Water kefir is usually made into a soda by the second fermentation process where flavors are added using fruit juice, herbs and spices. This makes water kefir a great substitute for soda pop which is high in sugar with no beneficial probiotics. It can be used to make healthy punches providing carbonation and a tangy flavor.
Milk kefir grains are used to convert a variety of dairy products into a thickened yogurt like product. The grains are made up of polysaccharides, lipids and proteins which house a wide variety of acetic acid bacteria, lactic acid bacterial species and yeasts. Depending on the grains heritage and current environment this community of microorganisms varies widely. Some samples of grains have had 30 different species identified where others have found to contain up to 60 or more.
Milk kefir grains also provide a wide variety of probiotic strains, vitamins and increases the availability of minerals which are found in the milk it ferments.
The reason to this variation could be attributed to the age of the grains, the location, type of milk(s) the grains have in contact with and the season. The cultures use the lactose and other available sugars in the milk as energy, this reduces the amount of lactose in the dairy product making it more easily digested by those who are lactose intolerant.
Kefir has a higher probiotic count of both water kefir and yogurt and can be thickened to closely resemble yogurt, cream cheese and if placed into a cheese press it can be made into a hard cheese.
The grains are very hardy and versatile being able to ferment a wide variety of liquids including, any animal milks like goat, sheep, buffalo and camel, nut and seed milks and for short durations can be used to make water kefir.
Conditions which affect the kefir grain culture
Not all water kefir grains contain the same species of bacteria and yeast. The ratio between the cultures also differs depending on the temperature, humidity, the food source and length of fermentation time. Each of these variables will change the kefir grains structure, population and makeup.
When kefir grains of either type are exposed to warm temperatures over a period of time the heat loving yeasts begin to grow rapidly. As a result the kefir will taste yeasty and it will have a higher amount of alcohol. The yeast saccharomyces cerevisiae which is the yeast with a high tolerance to alcohol grows rapidly between the temperature of 30 and 35. Cooler conditions slow the growth of the yeasts which can promote the growth of lactic acid bacteria making the kefir sour.
Humidity affects the transference of oxygen between the culture and the atmosphere. This is because in dryer climates evaporation drives molecules out of the ferment which slows the absorption of oxygen into the ferment.
The food source which the kefir grains have available change the ratio of cultures because each of the present cultures have different methods breaking down the available sugars. This is why milk kefir grains sometimes need to get used to a change in milk types. Although changing the milk fat content of cow’s milk usually does not negatively affect the taste of the kefir more radical changes like switching to goat’s milk or sheep’s milk may take one or two cycles before it stabilizes on a flavor profile.
Water kefir grains can also may need a period of transition when switching to different types of sugar. White sugar has the least additional minerals which makes it difficult for those cultures which rely on specific minerals for growth. Those more dependent on available minerals for efficient growth are inhibited when fed only white sugar. Changing to brown sugar, honey or molasses will produce water kefir with different flavors and will take time to stabilize.
The length of time kefir ferments will affect the ratio of yeasts, lactic acid bacteria and acetic acid bacteria. Yeasts and lactic acid bacteria use simple sugars for food giving them a head start on the acetic acid which use the alcohol which the yeasts produce. Longer fermentation times change the kefir grains as the yeast and lactic acid bacteria growth slows down as the available sugars are used up. The acetic acid bacteria population increases as more alcohol is made available.
Is one type of kefir grain better than the other?
Both types of kefir grains have good and bad points. It all depends on your situation. If you are allergic to milk then the choice is easy, otherwise you can use either one.
Milk kefir is the only kefir which has been shown to be able to repopulate the gut with probiotics over a longer period of time so if you are trying to reestablish your gut microbiome milk kefir grains would be a better choice.
Water kefir is also a great substitute for cola so if you like a carbonated beverage during the day it can be a great substitute for pop. It is low in sugar, is pleasantly tangy and you can experiment with different flavors until you get something you like.
Try both types
Kefir in either form is easy to make only requiring a jar and a warm place to keep it. Both ferment for relatively the same time and will ferment at room temperature so you don’t have to have an incubation chamber.
Water kefir is usually made into a soda during a second fermentation stage which adds flavors and carbonates the kefir. This process is done with water kefir which has been fermented for 24-72 hours. Additional flavors have are then added to the kefir and it is placed into a pressure sake container to carbonate. It is important to understand this process because if you do not use the correct containers they can explode and cause serious injury.
Milk kefir can also be second fermented to add additional flavors and textures but it is usually added to creamy drinks like smoothies and milk shakes. It can be thickened by filtering out some of the whey and made into cream cheese for dips, dressings and deserts like ice-cream.
Making kefir with either type of kefir grains provides a wider spectrum of health benefits then their store bought counterparts. It is a good idea to try the store bought versions to see if you like either type but understand that your own homemade kefir will have variations which the store version does not.
This is not a bad thing. You have control of the flavors but there will be some failures so don’t be discouraged if your first attempts are not what you expected.
Kefir grains of both types are robust. They will rebound from neglect, improper feeding and rapid environmental changes.