Homebrewing Basics: Carbonation and Bottling
Whether it's the crisp, sharp carbonation of a Pilsner or the soft, creamy bubbles in a dry stout, carbonation is a defining texture of any beer style. Carbonation occurs naturally in beer since yeast produce carbon dioxide along with alcohol when they eat sugar. Giving the yeast a specific amount of sugar just before bottling produces exactly the amount of carbonation needed.
The amount of carbonation you get depends on the amount of sugar you add. When you're using corn sugar, you should use the following quantities:
- 0.5 ounces per gallon for low carbonation (dry stout, English ale)
- 0.9 ounces per gallon for medium carbonation (American ales, porter)
- 1.5 ounces per gallon for high carbonation (German weissbier, Belgian blond)
So if you are going to be bottling our American Pale Ale from last week, using 4.5 ounces of corn sugar for 5 gallons would give an medium level of carbonation.
Before you bottle, it's important to be sure that fermentation is complete. If it's not, then it's possible to get too much carbonation in the bottles. In the worst case scenario, the pressure will be too much for the bottle and it can explode. For most beer under 6% ABV, fermentation will be complete after 2 weeks.
In order to test for certain that the fermentation has completed, you will need to check the final gravity (or FG) of the beer a couple days before you bottle. To do this, sanitize your auto-siphon racking cane and remove enough beer to fill your hydrometer jar about 80% (usually about 3/4 cup). Place the hydrometer in the jar and make a note of the level it's floating at using the scale on the side. This measurement is the FG. Most fermented beer will have a FG between 1.010 and 1.020. Repeat the process the next day. Fermentation is complete when the FG measurement is the same for two consecutive days.
How To Bottle Your Homebrew
When you decide it's time to bottle, it's important to set aside at least 2 hours to get the job done, especially if it's your first time. It's also helpful if you have a partner to lend a hand while doing this. It takes awhile to sanitize all the bottles and the equipment, and having someone to hand you the next bottle or tip the bottling bucket is very nice.
Before you begin, make sure your equipment and bottles are ready to go. You'll need a bottling bucket (with a spigot), enough bottles for 5 gallons, bottle caps, bottle capper, an auto-siphon racking cane, a bottling wand and hose, sanitizer, cheap vodka, and of course, fermented beer and the appropriate amount of corn sugar. Once all of these are ready, follow these steps to bottle your homebrew.
- Thoroughly rinse out the dust and old beer that might be in your bottles
- Take out the appropriate number of bottle caps you need and let them soak in 1/2 cup of cheap vodka. They tend to rust a bit if you put them in regular sanitizer.
- Fill your bottling bucket with five gallons of water and add the amount of sanitizer specified on the package. Immerse as many bottles as you can fit in the bucket and let them sit for one minute. Remove the bottles and repeat until all are sanitized. Some people let the sanitized bottles sit upside down in the top rack of a cleaned out dishwasher.
- Sanitize the other equipment you'll be using: auto-siphon racking cane, bottling wand and hose (inside and outside!) Heat two cups of water in a pot and stir in the corn sugar. Boil for ten minutes to sanitize.
- Empty the sanitizer out of your bottling bucket through the spigot (to sanitize the spigot). Sanitizing residue will remain in the bucket (either foam or iodine). This is OK. The residue will not affect the flavor of your beer and it's important not to rinse it out. This goes for the residue left in the bottles as well.
- Use your auto-siphon racking cane to transfer the beer to from the fermentation vessel to the bottling bucket. You will want to leave a quarter to a half-inch of beer behind so that you don't pick up any sediment from the bottom of the fermentor.
- Gently stir in the sugar-water solution for at least 30 seconds.
- Connect the bottling wand to the bottling bucket.
- Fill a bottle to the top by inserting the wand to the bottom of the bottle and pressing it down. As you pull out the wand, it should leave the perfect amount of space at the top of the bottle. Set a cap on top to keep the air out (don't use the capper yet). Repeat for all bottles.
- Place the capper on each cap, firmly pushing down on the handles.
- Let the bottles sit at room temperature for two or three weeks.
- Refrigerate and enjoy!
Giving the bottles a few weeks at room temperature will allow the yeast to process the sugar and produce the carbon dioxide. I like to test a bottle after one week and again after two weeks to see how the process is coming along. Once you put the bottles in the refrigerator, the yeast will go into hibernation and stop eating the sugar, so you want to wait until you're pretty well carbonated before chilling your beer.
If you used this guide to bottle your American Pale Ale, I'd love to hear how it turned out! Post in the comments to let me know.