Getting the carbonation level correct every time can greatly increase your enjoyment of your homebrewed beers. Opening a beer bottle to find a flat, fizz-less beer or a beer volcano can both be disappointing experiences. Here are some pointers to finding that proper sound of gas release when you open your hard-earned bottle of homebrew.
Carbonating while a beer is in a bottle, also know as bottle priming or conditioning, is the most common carbonation method for beginner homebrewers. But also many experienced homebrewers and commercial breweries utilize this technique as well. Bottle conditioning utilizes the yeast still present in the beer to ferment a freshly added dose of sugar. Carbon dioxide (CO2) is created as a by-product.
The first step is to make sure that everything that the beer touches during this process has been properly cleaned and sanitized. This includes bottling bucket, siphon, transfer hoses, bottles, caps, and filling wand. Next, the beer is transferred out of the fermenter and into the bottling bucket with volume markings. The beer’s bottling volume can be recorded and a priming sugar calculation then can be made.
A measured dose of dissolved priming sugar that has been pasteurized via boiling, can then delicately be added to the beer. This should be very gently stirred into solution with a sanitized spoon, to ensure proper mixing of the sugar. Some brewers like to add the priming sugar to the bottling bucket prior to racking. This is advantageous because during racking a whirlpool can be created with the force from the beer exiting the transfer hose. This ensures a thorough mixing of the priming sugar, but the downside is that beer volume must be estimated.
If the sugar is not uniformly dissolved, it can lead to bottle-to-bottle inconsistencies in carbonation levels, so be sure not to rush this process. Alternatively, homebrewers can add carbonation tablets or drops directly to the beer bottles if they don’t want to deal with measuring out and mixing the priming sugar. The final step is to fill and cap the sanitized bottles with a bottle filler wand and capping tool.
Be sure to store the bottles in a fairly warm location, a few degrees above fermentation temperature, to assure that the yeast completely ferment the newly added sugar. Don’t rush it, wait a week or more before trying the first beer to test the carbonation level. If the beer has been aging for an extended period prior to packaging, roughly 3 months or more, then a small, fresh dose of yeast may be added to the bottling bucket to ensure bottle conditioning is successful.
The Variables of Priming
There are four main factors that need to be taken into account when calculating how much sugar to add: Beer temperature, sugar type, beer volume, and desired carbonation level. You can find a carbonation priming chart at Byo.com
Carbon dioxide is present in beer post-fermentation and the colder the beer, the more carbon dioxide will be found in solution. Not taking this into account can lead to over-carbonated beer. Any good bottle-priming calculator found online will factor this remnant CO2 level by asking for the maximum temperature the beer reached post-fermentation.
Sugar type is another determinant for how much to add. Corn sugar (glucose/dextrose) and cane sugar (sucrose) are the two most popular sugars used for priming because they’re consistent, leave no flavor once fermented out and yeast can easily consume them. Other priming sugars that homebrewers will utilize include brown sugar, maple syrup, honey, dried malt extract, agave syrup, and Belgian candi sugar. These types of sugar can add character to the beer if a brewer is trying to accentuate a certain profile.
The total volume of the beer in the bottling bucket is the value homebrewers need for this calculation. Be sure to utilize a bottling bucket with fairly accurate volume markings to ensure a proper reading is taken. If you try to guess the beer volume based on the quantity found in the primary fermenter, then you should factor for a 10% (or more if dry hops were added) loss in volume to material at the bottom of the fermenter such as break material, yeast, and hops.
The desired carbonation level is at the brewer’s discretion, but is often based on the beer style and norms for the style. Most standard American ales target their carbonation at roughly 2.3-2.7 volumes of CO2, while many British ales can be found in the 1.5-2.2 volumes CO2 range and German weizens maybe up in the 2.8-3.5 volumes CO2 range. Start off with these standard levels and you can play with the levels as you develop as a brewer.
Don’t rush this process. There is nothing worse than producing a great beer only to have it undone by improper bottle priming. Be sure to check and double check your numbers, make sure all the equipment that the beer will touch is properly cleaned and sanitized, and make sure the sugar gets well mixed.