If the airlock is not bubbling, it may be due to a poor seal between the lid and the bucket or leaks around the grommet. Fermentation may be taking place but the CO2 is not coming out through the airlock. This can also be caused by adding too much water to the airlock.
Within 24-36 hours, carbon dioxide normally starts bubbling through the airlock, as long as everything is working correctly and if the fermenter is sealed properly. Fermentation can take as little as 3 days if you are using a fast-acting yeast and the temperature is ideal.
For the first 12 to 24 hours, you won't see much (if any) activity in the airlock. The yeast is taking this time to gather its strength and multiply its numbers. For the next 1 to 3 days, you'll start to see bubbles popping rapidly up through the airlock.
The most common causes are: Dead (not vital) or unhealthy (not viable) yeast cells. Too little yeast pitched. Too much yeast pitched, causing excessive krausening and loss of healthy yeast through blow off.
Add more yeast.
Additional yeast may be able to revive a sluggish fermentation, although simply tossing in a fresh pack of yeast may not be enough, especially if most of the nutrients have been depleted. You're likely to have better results with a method called Kräusening.
If the airlock is not bubbling, it may be due to a poor seal between the lid and the bucket or leaks around the grommet. Fermentation may be taking place but the CO2 is not coming out through the airlock. This can also be caused by adding too much water to the airlock.
In most cases, too low a temperature is the cause of a stuck fermentation, and bringing the temp up is enough to get it going again. Open up the fermenter, and rouse the yeast by stirring it with a sanitized spoon. Sometimes putting the yeast back in suspension will get it going again.
You can tell if your fermentation is stuck if you notice no activity in your airlock and no layer of Krausen in the wort. A lack of changes in the hydrometer reading three days after the start of fermentation and a high amount of sugar in the brew is another tell-tale sign.
Yeasts need oxygen in order to permit sufficient growth of new cells, which are what are going to do the work of fermentation. If fermentation hasn't started at all, then try aerating or oxygenating it again, and preferably re-pitch with a fresh batch of yeast.
An Unsafe Ferment:
Visible fuzz, or white, pink, green, or black mold. Get rid of it. This means your ferment was exposed to too much oxygen, bad bacteria was introduced during preparation, or it was too warm. Either way, it shouldn't be consumed.
Trying an Open Fermentation
As soon as you notice fermentation starting to slow down rack into a carboy and put the airlock in place. Your fermenter should only be open during “primary” fermentation which is when the first 70% or so of your sugars are fermented (here's more on Primary vs Secondary Fermentation).
Bubbling. The lactic acid fermentation process produces lactic acid bacteria that create gases when they feast on the vegetables. These gases are often visible as bubbles throughout the jar after a few days at room temperature and are a good sign.
Fermentation times can be shortened by using powdery (non-flocculent) strains of yeast or by mechanically stirring the fermenting wort. The yeast can also be roused toward the end of fermentation by the injection of carbon dioxide or by using a re-circulating device.
The short answer: Although most ales ferment in 2-5 days, I always recommend you wait at least 2 weeks before moving to bottles/kegs for the best results. Lagers on the other hand ferment in 2-3 weeks followed by several weeks or even months to condition.
Primary Fermentation Primary fermentation occurs in the first vessel the wort is transferred into. Active fermentation usually takes place within 12 hours. It can take longer for liquid yeasts because of lower cell counts (more on this later), which may take up to 24 hours.
Active fermentation usually takes place within 12 hours.
It can take longer for liquid yeasts because of lower cell counts (more on this later), in which case it may take up to 24 hours. Primary fermentation typically takes 3 to 5 days and is the start of converting wort to beer.
'Water may only be added to wine, sparkling wine and fortified wine to facilitate fermentation if the water is added to dilute the high sugar grape must prior to fermentation and does not dilute the must below 13.5 degrees Bé. '
Note: Yeast can take 24 – 72 hours to show signs of fermentation. Give the yeast time to work before you start becoming concerned. If after 72 hours and no signs of fermentation, add dry yeast. If you are not sure if the yeast has worked or not; take a hydrometer reading, or taste the beer.
If your fermentation is complete, but you aren't happy with the approximate ABV, you can always add more sugar to bump it up. Just make sure to use a yeast strain that is more tolerant to higher ABV, such as a Champagne yeast.
If there are still bubbles in the airlock after 14 days let it sit for another few days, or at least until there is no bubbling for at least a minute or two. Once there is no activity in the airlock, fermentation is complete.
For brewing with Mr. Beer, we always recommend that you bottle your beer no later than 24 days in the fermenter. You can go longer but the longer your beer sits the more chance you have to get an infection and get off-flavors in your beer.
A: Bulk fermentation typically lasts anywhere from 4-24 hours, depending on the recipe and the temperature of your kitchen. Generally, the warmer the environment, the shorter the bulk fermentation time. During bulk fermentation, the dough should double in size and become more elastic.
For styles such as American Amber Ale or German Altbier, we recommend 1 week in the primary and 2-3 weeks in the secondary. As a beer gets darker in color it becomes more important to let the beer sit longer in the fermenter.
Most brewers use ale yeast, which ferments quickly at moderate temperatures. However, some brewers use lager yeast, which ferments slowly at lower temperatures. Therefore, adding more yeast to the wort will not necessarily speed up fermentation. Too much yeast can lead to off-flavours and a shortened shelf life.