How to Reduce Fermentation Time
Is your kombucha taking forever to mature? In this post we take a look at some of the possible reasons for this, as well as what you can do to speed things up.
In general, slow brewing kombucha is considered to render a better end result than fast brewing kombucha. Slow brews give good depth of flavor, diverse probiotic levels and usually reliable carbonation.
Short and fast ferments are apt to give kombucha give a shallow flavor profile, often with too much or too little carbonation, and an immature but sharp taste.
However there such a thing as a ferment which just takes too long to mature. Perhaps it seems to have stalled completely, or maybe it is just taking too long for practical reasons. If this is the case, then there are some things which you can tweak to speed up fermentation and decrease brewing time.
Extremely sluggish ferments can an indication of a problem with conditions, ingredients or the SCOBY culture itself. If there is a problem in one of these areas, then rectifying it will probably bring your kombucha down to a more normal brewing time.
4 Ways to Reduce Fermentation Time
Long slow ferments are usually caused by two things. Low temperatures and/or a low amount of yeasts. However ferments which seem to stall completely, or ferment slowly and also give other problems, can also be a sign of a weak SCOBY.
Another factor which can influence rate of fermentation is the sugar to tea ratio present.
Let’s take a look at how these elements can be used to reduce overly long fermentation times.
# 1 Increase the Brewing Temperature
The first place to start when wishing to speed up fermentation in kombucha is to ask yourself ‘what temperature is my kombucha brewing at?’
Kombucha does best when brewed between 69-84 degrees. The further down this set of temperatures it is brewed at, the slower fermentation will take place. Kombucha can still be brewed at even lower temps, but it will take quite a long time to get to maturity, particularly if you like your kombucha strong and sour.
If your kombucha is brewing within the 69-84 degree range, then raising the temperature for your kombucha might not be the best plan. As mentioned above, longer and slower ferments are preferable to fast ones. If your kombucha is brewing at the upper end of this range, then definitely look at the other options for decreasing brew time and do not raise the temps any further merely to get a quick batch of booch.
Ways to Increase Brewing Temperature of Kombucha
If you are wanting to raise the temperature of your brewing kombucha, then there are a few different methods which you can use, depending on how much you need to raise it by.
Find a Warmer Brewing Place
The first thing to do, is to look for a warmer brewing position. If you are only looking to raise the temp of your brew by a few degrees, then you might find that simply moving your kombucha to a cosier spot will do the trick. Warm spots can include close to the back of refrigerators (where heat is produced), close to entertainment systems which heat up at night, or simply in a room on the sun side of your home. However make sure that you do not place the kombucha in direct sunlight as this can harm it.
Use an Electric Blanket
If temperatures are super low, then you will probably need to look at some artificial method of heating. One household item which works well for this is an electric blanket. Simply wrap it around your kombucha and turn it on to the lowest setting.
Use a Kombucha Warmer
Also available nowadays are warmers specifically designed for kombucha! Brewers report good results from these, and if you are living in a climate where your kombucha is exposed to very low temperatures – then this can be a good investment.
For more info on warming up your kombucha, check out How to Brew Kombucha in Cold Weather.
# 2 Encourage the Yeasts
Another factor which might be slowing down fermentation time can be a low level of yeasts. Cold temperatures are often responsible for abnormally low amounts of yeasts in kombucha. Yeast in kombucha takes the form of long brown strings ,as well as particulate. If you are not seeing much of either of this, then stimulating the yeasts can be good way to speed up your kombucha a bit.
Raise the Temperature
This ties into the above section. Yeasts prefer warmer temperatures to their bacterial friends within the SCOBY, so any rise in brewing temperature will give them a boost. But remember, only do this if your brewing temps are at the lower end of the scale.
Do Not Wash Your SCOBY
If you are washing your SCOBY, stop. While SCOBY washing can be a useful way to reduce yeast levels if they are in excess, this is usually not a good thing to do on a continual basis. The main yeasts strings in kombucha tend to hang off of the SCOBY. Some are free floating, but a large part are loosely attached to the culture. Washing tends to take these off – which means a reduction in the amount of yeasts going into each new brew.
Use Cloudy Starter Liquid from the Bottom
When taking starter liquid from whatever container it is in, try to take some from right at the bottom. This starter liquid will usually be cloudy and contain floating or settled particulate. This is also yeasts – in free floating form. Using this yeast-rich starter liquid will give each new brew a boost of yeasts.
# 3 Use the Right Amount of Sugar
This is pretty much linked into to encouraging the yeasts. They are the ones who eat the sugar, processing it into alcohol, which in turn feeds the bacteria.
The Correct Ratio of Sugar to Tea
The correct ratio of sugar to tea for kombucha brewing is 1 cup of sugar:1 gallon of tea. Check to see how much you are using and adjust up or down to meet this ratio.
Using too Little Sugar
If you are not using enough sugar, the yeasts will not have enough to eat, and will diminish in population in accordance to the level of food they are given.
Using too Much Sugar
Using too much sugar however is also not a good idea. The presence of too much sugar can cause what is known in the brewing industry as the ‘Crab Tree Effect’. The Crab Tree Effect is essentially similar to what happens to us after we eat a big meal. We get sleepy and lazy and do not feel like eating anything further for some time. When given too much sugar, the yeasts do the same, getting sluggish and lazy and sometimes causing a complete stall in fermentation!
# 4 Make Sure that Your SCOBY is Healthy
Another reason for super long ferments can be an unhealthy SCOBY or one which has lost its vitality. This is most likely to be the case if the other factors above are not relevant. If your brewing temps are average, your yeast populations decent, and your sugar quantity correct – then there is a chance that your culture is not well, or in dormancy.
Healthy, Sick, Old or Merely Dormant SCOBYs
Indications of a Healthy SCOBY
SCOBYs which are full of vitality usually do the following:
- Grow quickly.
- Reproduces and make new layers fairly rapidly.
- Has a good balance between yeast strings and cellulose body.
Indications of an Old SCOBY
SCOBYs which are lacking in lustre tend to exhibit the following:
- Very slow SCOBY growth or none at all.
- Very dark in color.
- Soft and fragile in texture.
- Flakes off from the underside.
These signs usually show that the culture is old and it is time to chuck it out. If this is the case, hopefully you have some new ones in storage in a SCOBY hotel, and you can simply bring in a new recruit.
SCOBYs which have been attacked by mold or fruit flies (who lay eggs in the surface) are not suitable for further brewing and should be thrown out. SCOBYs which produce kombucha which does not smell nice and has an acrid or stinky smell should also be disposed of as there is something wrong. The one exception to this rule is the smell of nail polish remover! This is a harmless phenomenon which can manifest from time to time. If you have encountered this and want to read further about it check out What To Do If My Kombucha Smells Like Nail Polish Remover.
In some cases SCOBY are not so much as lacking in health, as merely dormant. If you have taken a new SCOBY out of storage, or just recieved one in the post or from a friend, it might take a few brewing cycles for it to begin brewing at full power.
What to Do
As you can see, there are a lot different states your SCOBY can be in which will influence brewing times.
The first thing to do is ascertain whether your SCOBY is healthy or not. If it is in good shape, then you can rather have a look at the other ways in which to reduce brewing time. However if it seems that the SCOBY is the root of the stall in fermentation – consider if it is just merely slightly dormant still, or actually sick. All SCOBYS which are properly sick (mold, sticky kombucha etc) should be thrown away completely. However if it the culture is merely dormant, then do nothing except allow it a few brews to become fully active.
# 5 Add Another SCOBY
Another method you can use to speed up fermentation some what is to double up on SCOBYs. If you are using a large fermentation vessel, and your SCOBY is still comparatively small in relation to the amount of tea which it must ferment – then adding another SCOBY from storage is a great way to speed things up a little.
Kombucha which takes overly long to ferment can be an indication of something wrong with the fermentation or culture. If your kombucha is taking very long to complete its brewing cycle, then it is important to examine the factors and determine if there is a problem with the conditions or with the SCOBY itself.
Be aware that artificially speeding up a ferment too much can result in substandard kombucha which is flat in flavor and erratic in overall fermentation results. So, if all is inherently well with your ferment, it is just taking a little extra time to mature – then consider carefully before speeding it up just to reduce brewing time for its own sake.