As any brewer can attest, the most exciting part about opening a bottle of your own homebrew is that moment when you hear the "pssst" that happens when the pressure inside the bottle tries to equalize with the pressure outside of the bottle, indicating a potentially successful carbonation. When that sweet little sound doesn't happen however, the heart of the brewer sinks a little (or a lot), knowing that bottle will not be consumed with the long anticipated pleasure.
The majority of our clients begin their brewing adventures by bottle conditioning (carbonating) their beer...this is the process of adding sugar (corn sugar, honey, maple syrup, molasses, any sugar really) to the finished beer during bottling, to carbonate the beer (average for ales is around 2.3 volumes but this value can and should change depending on the beer style).
The carbonation is created when the yeast, (still suspended within the beer), has a new sugar to feast on, causing a mini-fermentation (conversion of sugar into alcohol and CO2) to occur in the bottle. The result (if done correctly), is that plethora of beautiful bubbles that assist in forming the thick foamy head on top of your beer while tickling your tongue into brewy submission!
So what do you do when on one day you open a beer and it seems to be wildly carbonated (to the point that it hurts your fingers when you open the bottle) and the next day, barely a bubble forms? This question is one of the most common we hear and so it seemed logical that we should offer some guidance on how to sort out the much needed carbonation dilemma so that nobody ever needs to feel the pain of not hearing that "pssst" sound again!
A few things you can do to ensure carbonation consistency:
1. Amount of priming sugar used
The most significant factor in properly carbonating your beer is the amount of sugar used during bottling. Too little sugar and your beer will be flat...too much sugar and you will create a bottle bomb!
SOLUTION: Calculate the correct amount of sugar for your beer style using an online "priming sugar calculator".
2. Mixing your priming sugar solution into the beer when bottling
I know we tell you that it is important NOT to mix your beer aggressively during bottling, and this still holds true because you still want to avoid oxidizing your beer (and creating off flavours). BUT if you don't mix the priming sugar/water solution and the beer together thoroughly, you may end up with some bottles as carbonation-less duds and others that would equate to bottle bombs!
SOLUTION: Mix the solutions together GENTLY but thoroughly throughout the bottling process.
3. Headspace in your bottles
When bottling, how much headspace are you leaving? This is the open space between the top of your beer and the cap. If you are leaving more headspace than this in your bottle, the CO2 will not stay in solution and will instead fill up the empty space in your bottle. So, you may open the beer and get a comforting "pssst" but your beer may still be unintentionally under carbonated anyway.
SOLUTION: Leave between 1/2" to 1" of headspace in your bottles when filling.
4. Carbonation Temperature
Many of our clients have said, "I store my bottles in the basement while they carbonate" with the assumption that the cooler temperatures are better for their beer (the way a cold room is for food). This couldn't be further from the truth however. Remember that the process of carbonating your beer is actually an additional fermentation and the yeast in your beer needs to be warm to be active. The colder the yeast is, the slower the carbonation process will be because the yeast will be sluggish.
SOLUTION: Store your bottles at around 70F (room temperature) for at least two weeks before cooling in the fridge and serving. If after two weeks, check one bottle and if it seems your beer is not carbonated enough, leave the batch for an additional week before testing them again.
As always, we love answering your questions so please keep them coming!!
Happy Brewing :)