Step 10: The Lowdown on the Cooldown
At the end of your boil time, you have to get the temperature down. If you try to pitch the yeast at too high of a temperature they may just die right off. If you get it down farther, those little beasties may survive, but they may be so stressed that they can’t finish the job, or they give off all sorts of flavors. Although, in a style like this, where so much of the flavor comes from the yeast, that might be a good idea.
To do this you have a few options. The most basic is to take your pot and put it in an ice bath. It is better than putting a bunch of ice around the pot, or even in a snow bank in the winter. Water has a higher thermo-conductivity than air, and it will be able to take heat away quicker than the air.
A step above that are various types of wort chillers. The simplest one is a bunch of copper tubing coiled up, placed in the pot, and cool water run through the chiller. This is what I have. You can make your own pretty easy with some soft copper tubing, or you can by one at your local homebrew shop. One thing I found my first few brew sessions is that your tap water only gets so cold. In high summer it is almost 80 degrees, and if your tap water is 80 degrees, then this wort chiller isn’t going to bring the temperature down lower than this. You might have to combine the wort chiller with an ice bath at the end, or you can run some of the hosing to the work chiller through an ice bath to lower the temperature of the cooling water.
This works faster than a simple ice bath because it uses both conduction and convection. I talked about how water has a higher thermo-conductivity than air above, and this wort chiller takes care of this. It also uses convection, which is the movement. A fluid in movement, will change temperature faster than a fluid that isn’t moving. It’s the same reason a convection oven cooks foods faster than a traditional oven. Another trick that takes use of convection is stirring. Stirring the wort with any of the above methods will cool the wort faster than just letting it sit motionless. Just make sure to only use a sanitized stir spoon, as the wort is chilling, and heat will no longer kill off the nasties.
Whatever method you use, try to get your wort to the temperature that you are going to ferment at. Generally for Ales this is between 60-65 degrees. The room in my basement I use, seems to stay at 65 degrees year round, so it is perfect for me. Most people should probably just find the coolest room in their home and not worry about it. If you want to get more advanced, there are all sorts of fermenter temperature controls that you can make or buy.
Step 11: The Final Step
Now you have your wort to fermentation temperature. You need to aerate it. It is the only time in the fermentors life that you want to slosh the wort around. When you pitch your yeast, the first thing the little beasties do is reproduce. To reproduce, the yeast requires a lot of oxygen. This will give them a good population to start fermentation which will start after the oxygen is used up. Your job is to get as much air into the wort as possible. Some people use fish tank aerators, but unless you have about 20 gallons of wort, and it can’t easily be lifted, I don’t think you need one. Simply pour the wort from the pot into your fermentation bucket (through a sieve) as vigorously as you can without splashing everywhere. You might even want to pour it back and forth between the pot and the fermentor a few times. This probably won’t be too feasible if you are using a carboy. Then you can tip the fermentor slightly onto its edge and rock it back and forth a few times. If you do this, your yeast should have plenty of air. Then top off the fermentor to about 5.5 gallons. You can do this with previously boiled water, but if your water tastes good, it will usually be alright.
This might be a good time to measure your original gravity. You can either do this with a hydrometer, or if you want to spend the $40 a refractometer. The gravity is the amount of sugar in your wort. A gravity of 1.00 is water (i.e. no sugar). After fermentation you can take the final gravity. Most ordinary strength beers will have an original gravity around 1.050 and a final gravity around 1.01-1.02. Since yeast turns sugar into alcohol and CO2, and does it more or less at a standard rate, given an original gravity and a final gravity, you can get a good guess at the alcohol by volume.
To find the gravity using a hydrometer, you put your hydrometer in the sample holder. You fill up your holder with your wort/beer until the hydrometer floats, spin to remove bubbles, and read the number on the side. Since most hydrometers are calibrated for a certain temperature (usually 60 degrees). You need to use the calibration formula on your hydrometer for whatever temperature you wort is at. Now that you just read my instructions on using a hydrometer, take them with a grain of salt. From the readings I was getting for original gravity, I was either failing to use both the refractometer and the hydrometer, or I screwed up my recipe somewhere, because I got an original gravity of about 1.081, when it should have been between closer to 1.060. I hope it turns out alright.
Now it’s time to pitch your yeast. This does not mean you should throw it into the fermentor. Take the yeast package and dip it in the sanitizer. Open it, and pour it into the wort. If yours has a nutrient pack inside (which of course you previously smacked open), make sure it doesn’t fall in the wort. If you have a starter, just pour it in.
Put the cover or plug on the fermentor and put the fermentor in the location it is going to rest for the next few weeks. Take your airlock, and fill it to the line with sanitizer solution, vodka, or some other liquid that won’t mold and place it in the hole in the cover or the plug. Within a few days, your airlock should be bubbling nicely, and soon you will have beer!