Bottle-conditioning is the most common way for homebrewers to carbonate their beer. Even for those of us who keg, we bottle-condition beers meant for competition and ageing (more on this later).
The concept behind bottle-conditioning is to take your fully-fermented beer, add priming sugar to it, and then bottle. Yeast consumes the priming sugar, and converts it into alcohol (trace amounts when bottle-conditioning), as well as creating CO2. The only difference between bottle-conditioning and the primary fermentation of your beer is that the CO2 has nowhere to go, and so it dissolves into the bottled beer. Carbonation is measured in volumes – 1 volume is 1 liter of CO2 at 20°C at 1 atmosphere in 1 liter of liquid (beer). Depending on beer style, the volume of CO2 can vary greatly (eg. British Ales often have ~1 volume of CO2 while a German Hefeweizen will often have ~4.5 volumes of CO2).
How To Bottle-Condition:
1) Once your beer has reached terminal gravity, (check with a hydrometer for three consecutive days that the gravity is stable) you are ready to bottle. We usually won’t touch our beer for the first 10 days so as to limit the risk of infection.
2) Sanitize clean bottles (not a typo — you can only sanitize clean bottles. Sanitizers, like Star San, will not sanitize residue, and, therefore, you risk infection). Sanitize all other equipment (hoses, siphon, bottling bucket, caps — even your bottle-capper).
3) Rack (transfer) your beer into another (sanitized) vessel. This is to get your beer off the trub (pronounced “troob” — also referred to as a “yeast cake” — it is the muddy substance on the bottom of your fermenter, consisting of live yeast, dead yeast, hops, protein, and other things you don’t want in your beer). You want to leave the trub in the original fermenter to ensure that it doesn’t end up in your bottles. An auto-siphon is the best way to transfer beer, at this level of homebrewing. While transferring, try to not let your beer splash. Introducing oxygen after the onset of fermentation is bad. While yeast uses oxygen to bottle-condition your beer, there is always such a thing as too much O2.
4) Measure fermentable sugar for desired carbonation. Boil sugar in a small amount of water. Cool. Add to beer. Stir thoroughly while ensuring that you do not splash. Some brewers will add the sugar to the bottling bucket before adding the beer on top. This is a great way to distribute the sugar in the beer, but by no means is it necessary. A mash paddle will work just as well. A spoon will do in a pinch. Just remember –avoid aerating the beer.
5) Transfer beer into bottles (using a bottling-wand at the end of the hose). Cap the bottles. Leave bottles in room temperature for ~three weeks before chilling.
While the process is relatively simple, homebrewers often encounter problems. The two biggest problems are infection and “bottle bombs”.
INFECTION: Infection of beer occurs when wild yeast or bacteria invade the beer, thus spoiling it. This most often happens during bottling because homebrewers “suck-start” their siphon tube. Our mouths are the most bacteria-laden parts of our bodies, packed with bugs that would love to spoil your precious beer. Some homebrewers will first gargle with liquor such as vodka, but this is the flawed method of amateurs. While taking a shot of vodka will likely reduce your chance of infection, your beer is still at risk. Besides, think about it, you went through all the trouble to brew and ferment your beer, nurturing it for weeks — do you really want to be a “sucker” and risk it all? Do it right — have that shot of liquor after to celebrate a properly conducted bottling process. The best way to safely siphon your beer is to use an auto-siphon. This simple device is as easy to sanitize as it is to use. A few pumps and your beer is transferring.
BOTTLE BOMBS: Bottle bombs are caused by over-priming your beer with sugar before bottling. Yeast produces so much CO2 that the bottles actually explode. Not only do you lose all your beer, you end up with a big mess, and risk injury. The biggest mistake that homebrewers make is to add priming sugar to each bottle, rather than adding all the required sugar to the entire batch before bottling. The problem is that it is far more difficult to weigh out an exact teaspoon of dextrose 50+ times, than it is to weigh out 4 ounces of dextrose once. Even if you are slightly off in weighing out the dextrose before adding it to the batch, the amount you’d be off by for each bottle, hopefully, will be less. Of course, there are always rookie homebrewers who think that if a little bit of priming sugar is good, than a lot is better. Brewing beer is about craft perfection, not crap projection. Check out our REFERENCES page for an online reference to calculate the amount of priming sugar that you’ll require.
COMMON SOURCES OF PRIMING SUGAR:
Dextrose AKA Corn Sugar: The most popular sugar source to bottle-condition with. Easy to use, and imparts no flavour. This is what we use.
Table Sugar: There is a long-standing taboo surrounding the use of table sugar when it come to bottle-conditioning. The believe is that using table sugar will impart a cidery taste to the beer. Some new-age thought is that the cidery taste is actually caused by other factors, and that table sugar works just fine without imparting flavour. We, currently, believe that too.
Honey: Yeast love honey. One trick that homebrewers use is to bottle-condition with honey in attempts to seal in honey aroma that is usually either boiled off or off-gassed during primary fermentation.
Molasses: Works well too. We haven’t used this sugar source for priming, but have read that molasses will contribute flavours to your beer.
Note that the amount of priming sugar required to hit your desired carbonation varies between each sugar source.
PROS AND CONS TO BOTTLE-CONDITIONING:
- Minimal, relatively cheap equipment (bucket, hose, auto-siphon (don’t be a sucker!), priming sugar)
- Easy to calculate sugar required to carbonate (see our REFERENCES page for a great link)
- Helps to keep beer from spoiling. Yeast consumes oxygen, thus reducing oxidation. We bottle-condition beers that we plan to age.
- Cosmetic “flaw” of yeast layer upon the bottom of the bottle. There’s no way to avoid it in the bottle. If you are careful, you can avoid the yeast ending up in your glass. Still, you won’t get the professional “look” of a beer that has been force-carbonated in a keg. Some beer-styles, such as German Hefeweizen and Belgian Wit, demand a yeasty opacity for both look and taste. Other beer-styles, such as a pilsner, would be ruined were they poured cloudy.
- Infection & “bottle bombs” — both are problems of the homebrewer, and not problems of the bottle-conditioning process.
- Conditioning time — As opposed to bottling from a keg, bottle-conditioning beer takes about three weeks to properly carbonate your beer. Unless you have a well-planned pipeline, you may find yourself oft without beer, waiting for your next batch to carbonate — reduced to drinking partially-carbonated beer in a failed test of patience. Bad.
When bottle-conditioning high alcohol beers, many brewers feel that a small addition of viable yeast (typically a packet of re-hydrated dry yeast) is good practice. The belief is that the high alcohol will have killed and mutated many of the original yeast cells, and so adding new yeast will ensure a “healthy secondary bottle-fermentation”. Another practice is to add some yeast from an actively-fermenting beer (during “high krausen”). This is done by opening the primary fermenter of the actively-fermenting beer, scooping away the outer-layer of the krausen with a sterilized spoon (it contains undesirables such as hops), and removing a small amount of the inner-krausen. The inner-krausen is where the very healthy yeast can be found.
PUT A CAP ON IT
If using bottle caps, it’s best to find ones that can be used on both “twist-off” and “pop-off” style bottles. This will mean that you don’t have to only buy (typically) premium, European “pop-off” style bottles. You can also find “oxygen-eating” bottle caps that will help reduce the oxygen in your beer, thus further reducing oxidation. When using caps, it is best to store your beer standing-up to reduce the amount of surface area (will also help to reduce oxidation).
PUT A CORK IN IT
Belgian beers were, traditionally, the only ones that you’d find corked. These days, many breweries and homebrewers are corking their beers. Corks require special bottles, and you must use wire cages (think champagne bottles) to keep the cork from popping out. When using corks, it is best to store beer on its side (up to debate). While there is more surface area, corks should be , we believe, kept wet to keep them from drying out which will increase oxidation.
WAX ON/WAX OFF
Dipping bottle-necks in wax is a very old, awesome, practice. Not only is it aesthetically pleasing, it also serves as a barrier between your beer and the outside world. Bottle caps (like corks) are not perfect barriers. There is research that many hop volatiles escape rather quickly from capped beer. Wax will help to keep bad things out while keeping good things in.
Brew your beer. Bottle your beer. Love your beer. Just do it the way that you will appreciate it most.