Water Kefir FAQ: During the Ferment | Yemoos Nourishing Cultures

How do water kefir grains convert the sugar-water they're in to kefir?

Kefir grains are an amazing symbiotic matrix of bacteria and yeast that work together to feed off the natural sugars (and sometimes proteins and fats too, especially in the case of milk kefir) found present in the sugar-water and dried fruits. The yeast and bacteria co-operate, making the nutrients that are inaccessible to one digested into accessible nutrients for the other. Yeasts break down the simple sugars like glucose and fructose, turning them into ethanol and acetic acid. Lactic and acid-producing bacteria (such as lactobacilli) convert sugars (such as sucrose) and complex carbohydrates (starches, etc) into simpler sugars and lactic acid. Lactic and acetic acids naturally preserve as well as stave off harmful foreign bacteria. The result is a drink that has had much of the sugar converted to simpler sugars, lactic and acetic acids, carbon dioxide and ethanol. It also contains millions of probiotics and is more nutritious in some regards because of the more bio-available and digestible nutrients from the sugars and dried fruits including an increase in vitamin C and many B vitamins.

Can kefir be in direct sunlight?

This is not really recommended, as it can more easily encourage other bacteria to grow if it heats up the jar too much (just like a fish tank in direct sunlight is more difficult to keep clean). Although if there is not an option, it shouldn't usually cause a problem. In our observations, water kefir placed on the window sill didn't prove to be any different or run any increased risk of contamination than our others placed in our darker kefir cabinet. It can also cause increased yeast or an uneven ferment. For now we still recommend kefir grains be placed in indirect light or dim light (such as in a cupboard) or a cool corner of the kitchen counter.

What temperature does water kefir prefer?

In our observations water kefir successfully kefirs at a wide range of temperatures, with its favorite range being between 65º - 82ºF (18º - 28ºC). 71º F (22ºC) is the most ideal usually. Anything above 86°F (30°C) can be damaging. Kefir can actually still ferment anywhere from 39°F to 86°F (4C°-30°C). This is why it will continue to ferment in your fridge, just at a much slower pace. If you live in a tropical or very hot climate, you may need to make some adjustments so that your kefir isn't constantly exposed to excessive heat (82°F/28°C or more). You can try fermenting in the fridge during the day, and letting it sit out on the counter during the night. Or you can immediately place the kefir in a thick cooler after pouring cold water into it (or add cool water or a little ice pack in the cooler to help keep it cool).

Can you add other things in with kefir while its fermenting?

Yes, (besides the usual dried fruit and lemon) but experiment carefully as some things may hinder or even harm the grains (some foods contain natural antibacterial properties, such as grapefruit and raw honey). Dried fruits are better tolerated than fresh fruits. You may be able to do fresh bananas, fresh carrots or fresh ginger though. And possibly fresh figs, coconut meat or dates if you have access. Some fruits, like raspberries, will dye your grains and may irritate them as well (especially fresh fruits because of the active enzymes and acids in them). Juice is also best to use as a flavor enhancer after you have strained the grains out for the same reason. You can just as easily add the desired ingredients or flavors after you have strained the grains out, and then let the kefir sit for 12-48 hours before consuming. Adding mangos, vanilla beans or raspberries are some of our favorite secondary ferment flavors (for milk and water kefir)!

Should kefir grains float?

Yes, sometimes. Most kefir grains encapsulate some of the carbon dioxide gas that the yeasts give off while fermenting. Also, some grains have less density than the liquid, and simply float. Some will be dense enough though (and manage to avoid capturing bubbles) that they remain on the bottom. Sometimes grains that have been subjected to severe freezer burn, high heat or their outer layer is too encrusted and hard from being dried (or old), also float (and they may not be able to be revived). It is best to see if these are able to propagate new grains (though they themselves may not recover) or toss them if no growth or kefiring is achievable with them. If they reproduce new grains, then you are good to go!

Should you stir kefir?

Most people give the kefir a good stir at the beginning to make sure the sugar is dissolved (it doesn't have to be fully dissolved). You can stir the sugar with the grains in the jar without any issue. Once the ferment begins, its best to just leave them alone for the duration of the ferment. Jostling the jar or stirring the kefir a couple times before its done fermenting won't hurt, but its not necessary.

Should I put a lid on Kefir?

Putting a lid on kefir while its fermenting will increase the carbonation (fizziness) of the final kefir quite a bit. Kefir grains thrive when exposed to oxygen and seem to do slightly better when the lid is breathable (a cloth, paper towel, etc). Also, it is safer to cover it with a breathable lid because of the risk of built up carbonation exploding the glass. This can and does happen, usually when a bottle is forgotten, or filled too close to the top. Make sure that if you're putting a tight lid on your kefir while its fermenting that you don't fill the jar more than 2/3 full. Just like soda, kefir will expand if enough carbonation has built up and not enough space was left; it will burst and climb right out of the jar when you open the lid. You can also achieve a happy medium by loosely placing the lid on the top to make it a tighter fit than a cloth would be, but still loose enough that air can escape. To avoid fruit flies, be sure that whatever lid or cover your are using, that it is secure and there are no large holes that a small fly (or other floating things like dust or pet hair) could easily get through. Keep in mind that when you bottle and store your strained kefir the carbonation will increase at that point too, so it isn't necessary to try to achieve carbonation during the actual fermentation when the grains are in it. We like to use a cloth and once our kefir is in the fridge for a couple days the carbonation kicks right in!

Does Kefir need a breathable lid?

Kefir functions best when it has oxygen. When you try to go anaerobic (no oxygen), you will be getting basically a carbonated kefir wine. Some people prefer to ferment with a tight lid to increase the carbonation (though this can be done at a later process). It also increases the risk of explosions when the lid is tight. We always ferment ours with a cloth of some kind as the lid.

What type of container can I ferment and store my kefir in?

Glass, ceramic or a food-grade plastic is recommended. Metal can leach when in constant contact with acidic liquids (such as kefir). A thick glass (such as anchor hocking, ball or kerr) with a rubber seal is recommended to lessen the hazard of stored kefir exploding.

How short or long can you ferment kefir?

This is completely dependant on the temperature as well as the volume of grains per cups sugar-water that you are using. For example, if you have a cup of grains in a cup of sugar-water (not recommended), it will ferment very quickly. If you have a teaspoon of grains in 4 cups of sugar-water (not recommended either), it will ferment very slowly. If you place the kefir and grains in the fridge, the same ferment that will usually take 24-48 hours may take 5-7 days or more. Likewise, this same scenario in a very hot room may take a half day (12 hours). The traditional way to make kefir is to find the balanced ratio of grains to sugar-water (+ temperature of the room) that will create a ferment that is just ready at 24-48 hours. The traditional amount of time is usually 48 hours for water kefir. This produces the optimal flavor and consistency, and the grains seem to thrive off this schedule. You can also do a secondary ferment-hybrid by straining your kefir at 12 hours, and then letting it ripen for another 12-48 hours (without the grains) before drinking. It produces a mild full flavor and is especially good when done in a bottle with an airlock lid.

How long does it take for dried or live shipped kefir grains to balance?

This can take anywhere from a couple days to a week. Water differs region to region (and brand to brand), so the grains will also be adjusting to new water (and sugar, fruit and lemons) most likely as well. Dried grains can take a little longer- a week to 2 weeks is common. Kefir grains may not start growing right away, but they should be properly kefiring the sugar-water they are in by this time. Growth can start happening right away, or it may take up to 3-5 weeks before you start noticing growth (usually the case with dried, not live).

How long does it take for stored, frozen or dried kefir grains to reactivate?

Stored grains from the fridge, freezer, or dried in the cupboard are very similar to re-balancing live or dried grains from the mail. It can take anywhere from a couple days to a week. Dried or frozen grains can take a week to 2 at the most. Kefir grains may not start growing right away, but they should be properly kefiring the sugar-water they are in by 5-14 days. Growth can start happening right away, or it may take up to 3-5 weeks before you start noticing growth (usually the case with dried, not live).

How do you know when the kefir is ready?

When you nudge the jar and bubbles fly up from the bottom, and if it has a sour bite (not just a flat extremely sweet water) it is most likely ready. To test just stick a straw or spoon in to try. 'Double dipping' is ok but not really recommended. Technically speaking this is at a ph of about 4.5, if you have a ph meter to test. Some people like to drink it at 24 hours while others like a tart and more bubbly kefir and will wait the full 48 hours. A lot of people expect a very sour and very bubbly drink - this is not the case until after you store it. Water kefir is mildly sweet-sour with just a tiny bit of bubbles when first strained. If you bottle it for a day or more, it will greatly increase in carbonation and reduce the sugar more (and increase the alcohol a bit). It truly is drinkable at any point so there is nothing to really worry over. Once you get into the swing of things you will naturally know when your kefir is done to your preference and how to tweak it or bottle it to improve flavor and fizz if desired. A mild kefir tends to have a laxative effect and an over-fermented kefir a constipating one, thus most people try to achieve a kefir somewhere in between.

What if I forgot to strain my kefir when it was ready?

Water Kefir garins are very forgiving. Strain when you remember, and feed them normally. They may be extra happy and eat through the new sugar-water quickly, so keep an eye on them and strain when it tastes ready (whether its before or after the 24-48 hour mark). If its been more than a week they may need some time to re-balance, and you may want to wait to consume the kefir until after a couple of cycles/batches.