Once your wort is between 68-75 degrees (don't guess on this one, use a sanitized thermometer), you can pour it into your fermentation bucket. The ideal temperature is 70 degrees. The fermentation bucket is the one without the hole in the bottom. As you do this, you want to splash the wort around really well, making sure you incorporate plenty of air. Yes, we've been telling you not to splash your beer, but this is an exception. This is the only time you want to aerate your beer, and its actually quite important to do this. The first stage of yeast development is aerobic and you lost all your oxygen during the boil, so it has to be replaced in order to grow yeast. Because the wort is already cool, the oxygen will dissolve, but it won't chemically bind to the beer. Once you have poured all your wort into the fermentation bucket, add another 3-3.5 gallons of water to bring the total volume of wort up to 5 gallons (you will have lost some volume during the boil). Stir the wort well to make sure the solution is well incorporated and aerated. Some brewers use their spray nozzle on their sink to add the additional water since this method incorporates lots of air into the beer.
Pitch (add) your yeast. It is a good idea to shake the yeast up to get it nicely dispersed in the test tube before you open the container. Once you've added the yeast, give it all one more quick stir, then put the lid on.
Note about the lid: The fermentor lid is very tight fitting, especially the first time you put it on the fermentor. You will have to push down with your weight to get it to snap in place. Some people use a rubber mallet to get it all the way on. You need to make sure you get the lid on correctly or else you will have air leaks.
Put the airlock into the hole in the lid, making sure it is well sealed. Fill the airlock half-way up with water, and store the fermentor in a calm, dark place.
You should start to see evidence of fermentation (the airlock will burp bubbles every now and then) within 24 - 48 hours.
If you don't see bubbles burping in your airlock within a day or two, try the following:
- Make sure your lid is on tightly and the airlock is secure.
- Make sure the temperature of the room that the fermentor is in is at least 65 degrees.
- Make sure you didn't expose your yeast to temperatures above 80 degrees.
- If you open the lid and you notice foam and bubbles on the surface of the beer, then it is fermenting. If you still aren't seeing the airlock burping its because you have a bad seal somewhere.
Your beer will ferment for about 7-14 days. The first few days of fermentation will be quite vigorous, and you may notice bubbles burping every few seconds, or even continuously during this stage. This stage is known as krausen. The beer will start to slow down after about 2-4 days. Once the bubbles occur less than once every 90 seconds, you can bottle.
Some people notice that fermentation seems to complete too fast (less than two days), if this occurs it is generally because the fermentor is either too cold (the yeast stalled), or too hot (the yeast fermented too fast and puttered out). The best solution is to ensure that the fermentor is right at 70 degrees while fermenting. If the fermentation did stall, the best solution is to fix the temperature and perhaps to give it a very gentle stir with a well-sanitized brewing spoon. In general it is best not to open the fermentor unless you absolutely have to, but if your fermentation is stalled, then you have to do it.