fermenting FAQs

By weighing the vegetables down and keeping them submerged below the brine, you create an anaerobic (oxygen free) environment. As moulds need oxygen to grow, this simple measure decreases the chance of mould growth forming. 

If your cabbage was a little dry going into the recipe, or you weren’t fermenting a large quantity of vegetable matter at the start, this can happen. If after a couple days you’re worried that mould might start growing, just whisk together a little 2% brine (100ml of water and 2g of salt) and pour just as much as you need over top of your vegetables in order to keep them out of contact with air. Continue fermenting as normal from there. 

Fermentation is a continual process and the flavours will develop over time. We recommend a taste test daily from day 7. Once the sauerkraut has reached your desired level of tanginess it’s time to move into the fridge.  

It’s possible your sauerkraut fermented in a room that was too hot. Higher temperatures can lead to the bacteria becoming a bit overactive, breaking down the structure of the vegetables. That doesn’t mean it’s unsafe to eat by any means, just not the most pleasant. 

Unfortunately, there’s no way to bring a mushy ferment back, so it’s best to start over and try again. Try fermenting in a cooler corner of your kitchen, in a well-ventilated area, or even in a cool cupboard. Beyond that, using tannic vegetable leaves (like blackcurrant or bay leaves ) will cause your ferments to firm up as they mature. Feel free to line the top of your sauerkraut with some of those leaves instead of a reserved cabbage leaf to help form a seal and improve the texture of your ferment. 

A good sauerkraut ferment will have a pleasant sour smell, with perhaps a faint note of sulphur, which comes from the cabbage. If it’s musty, smells like rotten eggs, or is putrid, something’s gone wrong. 

Ferments can be contaminated in a number of different ways, however not all forms of mould are harmful – get confident knowing mould from yeast and when it’s time to call time on your pet. 

A thin, white, crinkly film with no fuzz is often yeast. Specifically, kahm yeast. Kahm yeast can be skimmed from the surface and the ferment will still be safe to eat. Mould is raised and fuzzy, it can be black, white, green pink or blue. Should mould crop up, throw the whole ferment away.  

Visit our recipe pages for inspiration. 

Ferments can be contaminated in a number of different ways, however not all forms of mould are harmful (no double dipping!). 

A thin, white, crinkly film with no fuzz is often yeast.  Specifically, kahm yeast. Kahm yeast can be skimmed from the surface and the ferment will still be safe to eat. Mould is raised and fuzzy, it can be black, white, green pink or blue. Should mould crop up, throw the whole ferment away. 

Your own personal preference is a big factor here. Smell and taste it. If it smells pleasant to the nose and tastes sufficiently soured to your palate, it’s ready to transfer to the fridge. 

Yes! It will ferment faster during warmer months and slower during cooler months. Be wary of fermenting your kimchi in a room that’s too hot, as that can make the cabbage mushy. 

It’s possible your kimchi fermented in a room that was too hot. Higher temperatures can lead to the bacteria becoming a bit overactive, breaking down the structure of the vegetables. That doesn’t mean it’s unsafe to eat by any means, just not the most pleasant.

Unfortunately, there’s no way to bring a mushy ferment back, so it’s best to start over and try again. Try fermenting in a cooler corner of your kitchen, in a well ventilated area, or even in a cool cupboard. Beyond that, using tannic vegetable leaves (like whole tea leaves) will cause your ferments to firm up as they mature. Feel free to line the top of your sauerkraut with some of those leaves instead of a reserved cabbage leaf to help form a seal and improve the texture of your ferment. 

Many recipes for kimchi do use some types of preserved seafood, like dried anchovies or fish sauce. In our recipe, to keep it vegetarian and gluten free (in case there are any allergens in your household) we opted for the addition of tamari. But if you’d like it to taste a little richer, with a bit more funk, don’t shy away from supplementing the tamari with the same amount of your favourite fish sauce. 

Visit our recipe pages for inspiration. 

Without the sugar there is no fermentation. The sugar in water kefir is what the culture feeds on as it ferments. As it does so, the kefir grains consume the sugars and convert them to lactic acid and carbon dioxide. You can use less sugar than the recipe recommends, but we don’t suggest going below 5% of the total volume of your mixture as the ferment may not take hold. 

Yes, they naturally change shape. If not fed consistently they will be smaller and sand-like, if nourished by being fed often, they will grow into larger clumps. 

It is not possible to successfully exchange one for the other as the specific strains of microorganisms in milk kefir and water kefir are uniquely equipped to thrive off different sugars (lactose vs. glucose). 

Place the grains into the fresh sugar water and put them in the fridge in a covered container. They can rest in the fridge for up to 3 weeks. 

Yes, it is normal for the liquid to turn cloudy as it ferments. 

Not necessarily, however certain sugars are better for water kefir grains as they’re easier for the microbes to process. We use unrefined cane sugar, though brown sugar and even honey will all work, each add their distinctive flavour to your brew. Refined sugar will feed your kefir grains for a period, but it’s lacking in some of the complex organic molecules and minerals you might find in other sugars. 

Absolutely! Water kefir can take whole chunks of fresh or dried fruits which will lend their flavour to the brew. When it has finished fermenting, you can simply strain out the solids and separate them from the grains. Generally, think about adding 20% of the volume of your water kefir in fresh fruit (cut up into a medium dice), or 10% in dried fruits. 

Great additions for fresh fruits include berries, stone fruits like apples or pears, or tropical fruits like mango and pineapple. Feel free to even substitute some of the water/sugar mixture for fruit juices if you so desire. There’s lots of room to be creative. 

Check out our Strawberry and Lemongrass Water Kefir recipe.

SCOBY is an acronym for Symbiotic Culture Of Bacteria and Yeast. More specifically, it is the community of microorganisms that live in both the kombucha’s liquid and the thick, floating mat or “mother” as it’s colloquially called. 

You can use less sugar, but you cannot make kombucha without any sugar. Without the sugar there is no fermentation. The sugar in the kombucha recipe is what the SCOBY feeds off of. As it ferments, that sugar is primarily transformed into a small amount of alcohol, acetic acid and carbon dioxide while the microbes multiply. If you’re worried about sugar consumption, the sugar in the kombucha recipe can be dropped down to about 5% by weight, but note that the finished product will be much weaker in its final flavour. 

Kombucha’s taste will change over time. The longer it ferments, the less sweet and more like vinegar it will become. Left too long it can become overwhelmingly sour. It’s important to catch it at just the right moment in time! 

What most people visually recognise as the SCOBY isn’t actually the yeast or bacteria (even though they live within it) but a mat of cellulose – the same stuff that makes up the fibre in plants. SCOBYs will start off as thin translucent films and if the microbes in your kombucha are healthy and thriving the SCOBY will thicken as it ferments (most often into a smooth surfaced, opaque sheet, that is tan to white in appearance). Its buoyancy means it usually floats, but it may move around, sink, bubble up, or even tilt on its side as the mixture ferments and that’s totally fine. 

The older a SCOBY gets, the wispier and browner it may become. However, even if the SCOBY never grows large or thick, it doesn’t mean your kombucha has failed! Some liquids are just better at providing the raw building blocks the microbes need to construct a thick mat, but in its absence, it doesn’t mean they aren’t fermenting. 

Yes it does. The yeasts within the SCOBY produce alcohol that is then consumed by the bacteria it lives alongside when they turn it into acid. The process normally comes with a little lag time, meaning that there’s always a small amount of alcohol in your kombucha, most often in the range of 1-2%, or roughly what you’d find in overripe fruits. 

If left too long, your SCOBY can overferment your base, leading to it tasting more like vinegar than a refreshing tonic. The easiest way to fix this is to brew the same amount of the sweetened tea mixture that you did at the start of the recipe, but with half the sugar, and pour it in until the acidity is tempered to a palatable level. 

All manners of teas and tisanes can be used to brew kombucha successfully. Feel free to substitute the same quantity of tea bags for your favourite blend. You can even use strained fruit juices (like apple juice or cranberry juice) though you won’t need to add any sugar to those recipes to turn them into kombucha. 

If you’d like to grow your kombucha’s SCOBY you can store it in a “SCOBY hotel”. Simply dissolve 100g of sugar into 1L of water and add in the reserved 200ml of old kombucha along with your SCOBY. Cover the container with the gauze and a rubber band and leave it on your counter out of direct sunlight. Your SCOBY will consume the sugar and grow considerably in size, letting you take cuttings of it to share with friends or family who also want to get into brewing kombucha. 

If you are looking to farm your microbes however, your SCOBY can easily be stored in the 200 ml of reserved kombucha in a sealed container in the fridge for several weeks without any adverse effects.

Bottling your kombucha a couple days in advance of your estimation of when it will be finished will trap in any carbon dioxide produced by the yeast. From there, leaving the clip top bottle in the fridge for a little while longer will help to develop even more bubbles, so long as you aren’t opening the bottle often.

If you’re looking for champagne like effervescence, try adding a couple tablespoons (roughly 30g, or 3%) per litre into the mixture, before you bottle it. This will start a secondary fermentation that carbonates the mixture as the yeasts within the SCOBY ferment in the absence of oxygen. Be aware that this technique can lead to higher alcohol levels in your kombucha than if you were to consume it normally. 

A kombucha that you strain, bottle and place in the fridge still contains all the microbes responsible for fermentation in the first place. In the absence of the original SCOBY, the microbes in the kombucha will start growing a replacement raft, even in a bottle in the fridge. It doesn’t mean your kombucha is spoiled, simply alive! Just use a small sieve when pouring yourself a glass to enjoy. 

Milk kefir grains are globular colonies of bacteria and yeast living together in tight clusters in a symbiotic relationship. 

It’s a cultured milk product, so it has a mildly sweet, yet tangy flavour, reminiscent of yoghurt. Its sourness comes from the bacteria within the grains fermenting lactose primarily into lactic acid. 

The amount will vary from batch to batch. A small amount of naturally occurring alcohol is present in the finished product, normally around 1% by volume. 

It is not possible to successfully exchange one for the other as the specific strains of microorganisms in milk kefir and water kefir are uniquely equipped to thrive off of different sugars (lactose vs. glucose). 

We recommend whole animal milk, either cow, goat or sheep. Using whole milk will produce a thick, creamy kefir. Semi–skimmed and skimmed milk will produce a much thinner kefir with a less complex flavour. 

As mentioned above, the fat content of your milk plays a role in how thick your finished product will become, but thin milk kefir could be temperature related. Milk kefir will ferment faster at warmer temperatures and slower at cooler temperatures. If your jar is set near a drafty window, it may not ferment as quickly as it should, and therefore, not thicken. Try to find a reasonably warm spot in your kitchen if you can. If your milk hasn’t fermented after 48 hours, strain out the grains and start again with a fresh batch. 

If you are not baking on a regular basis, store your starter in the fridge until you are ready to. The cooler temperature will slow down the fermentation process and keep your starter ready for action. 

This is one of the less joyous pitfalls of fermentation! If left too long to its own devices (especially in an environment that’s a bit too warm) your starter can absolutely foam right out of its container. This doesn’t mean its ruined by any means. Try your best to salvage what still remains in the jar and use that as the 50g of starter to restart the feeding cycle. 

We recommend feeding the starter once a week whilst refrigerated. Feed it by first discarding all but 50g of the starter, then add 50g of wholemeal flour, 50g of strong white flour and 100g water. Stir the mixture together with a spoon before replacing it to the fridge. 

This is often referred to as hooch and indicates the starter needs feeding, it will smell slightly acidic. Discard this liquid, scrape off the top layer and discard your starter so you are left with 50g and then feed your starter. 

Once you have a healthy sourdough starter that has risen and fallen once, it is ok to switch the feeding flour. You can continue to feed with a mixture of wholemeal and strong white bread flour or even switch to using rye.