- Preparing the Sugar
- Add the Sugar Solution to the beer
- Sanitise the bottles
- Sanitise everything else
- Fill the bottles and cap them
How do you get your beer from the fermenter, nicely carbonated into a bottle you and your friends can enjoy? The brewing process isn’t over yet and we’ll be looking at a method called “bottle conditioning” to show how you can easily package your beers, then (most importantly) drink them carbonated.
Bottle conditioning is when some sugar is added to beer after it’s finished fermenting, and then packaged into bottles. The yeast in the beer will “wake up” and eat the sugars creating a small bit of alcohol and carbon dioxide. The CO2 will then dissolve back into the beer causing it to be fizzy.
This method is used not just by many homebrewers, but by many commercial breweries too. One of the advantages is no special equipment (like a CO2 cylinder, expensive bottling line etc.) is needed. It’s unpasteurised making the beer a “living product” and the flavour will change over time. This really suits malt and yeast forward beers as these flavours tend to improve, however hop character fades over time. Many people (myself included) still bottle condition IPAs and hop forward styles, but they won’t be the best styles for ageing.
Everything the beer touches from the moment it’s cooled from the kettle needs to be sanitised using a chemsan solution or similar. I have a handy spray bottle filled with the solution.
Step 1: Test the Beer
Before bottling, take a hydrometer reading to ensure the beer has finished fermenting. If the beer hasn’t finished fermenting and is put into bottles, this will over carbonate the beer and in some cases lead to bottle bombs – where bottles explode.
Try a sample of the beer too. Not only is it nice to have a sample of fresh beer but check you’re happy for it to go into bottles. Even though the beer may have reached terminal gravity, there may still be some fermentation off flavours which the yeast needs to clean up over time. It’s also useful to check that the beer hasn’t gone bad, so you don’t spend time and energy bottling a beer which is undrinkable.
Step 2: Prepare the Sugar
Measure out the sugar into a container and pour boiling water over it. Stir until all sugar is dissolved. Add more boiling water if necessary.
Sugar is required to make the beer carbonated, and the amount is dependent on the volume of beer, temperature it’s at, and how carbonated it needs to be. Here’s a simple calculator which will say how much sugar to add. I tend to go for 2.2-2.4 volumes of carbonation as this suits most styles of beer I make. But it’s up to you. I’d strongly recommend using a calculator as using too little sugar and the beer will be under carbed; too much and the beer will be too fizzy or in some cases lead to bottle bombs.
The temperature is quite important: the warmer the beer the less CO2 is dissolved, so more sugar will be needed to create more CO2. Conversely, the colder the beer the more CO2 will be contained within. It gets a bit complicated when the beer has fermented at different temperatures, for example an ale might spend four days at 18°C, then is ramped up to 20°C to finish it off, then cold crashed for five days at 4°C. In these circumstances I take a rough average of the temperature.
Not all sugars are equal. For most beers using dextrin (corn sugar) or sucrose (regular white sugar) is recommended. These sugars are very easy for the yeast to metabolise and won’t add any other flavours. In some cases, having fermentables which add character can be desirable. Brown sugar, muscovado, molasses, honey are all highly fermentable but will add some of their own flavour. It will be subtle in most cases but might add an interesting dimension to certain beers.
Step 3: Add the Sugar Solution to the Beer
Before opening the fermenter make sure the lid is sanitised. Make sure the outside of the container with the sugar solution is sanitised. Pour the sugar solution into the beer and using a sanitised spoon, very gently stir. Try not to oxygenate the beer or disturb the trub.
Doing this stage early on instead of just before dispensing into bottles is important because it gives the sugar more chance to evenly distribute throughout the beer. I’ve found this method gives the beers a more even carbonation, therefore making over carbed beers less likely.
Place the lid back on the fermenter once this is done.
Step 4: Sanitise the Bottles
Bottles can be reused, so save bottles from commercial beers, ask friends to save bottles, or go to bars and pubs asking for their empties. Bottles should preferably be brown or black. This blocks out the light frequencies which degrade hops and can add off flavours.
Make sure the bottles are clean. I’d strongly recommend cleaning the bottles just after they’ve been emptied i.e. once you’ve poured the last beer from them. Having a bottle brush to hand is great for getting rid of any stubborn yeast deposits.
The inside of the bottle needs to be sanitised. This can be done by filling a bucket with 15 litres of chemsan solution and shoving bottles in there, holding them down until they’re full. I use a bottle rinser to spray chemsan into my bottles, and let them dry on a bottle rack. Remember to clean and sanitise your bottle rack before use!
I place my bottle caps in the bottle rinser, but they can also be put into a bowl, as long as they’re submerged in a sanitising solution.
Step 5: Sanitise Everything Else
I’d strongly recommend using a fermenter with a tap making it possible to ferment and bottle from one vessel. Syphoning from one vessel to another introduces risks of oxidation and infection, which is avoided by keeping the process simple.
Using a tap also means it’s possible to use a bottling wand, which is the best tool a homebrewer could ask for! It attaches to a fermenter tap and fills from the bottom up, avoiding unnecessary splashing and oxygenation.
Make sure your tap and bottling wand are sanitised, and connect them up.
If you don’t have a tap, it is possible to fix a bottling wand to the end of a syphon tube.
Some homebrewers move the beer of the yeast cake due to autolysis, but on a homebrew scale you have to try really hard to make this happen. I’ve not experienced more trub in bottles by keeping my brews to one vessel.
Step 6: Fill the Bottles & Cap Them
Take a sanitised bottle and press onto the end of the bottle filler and wait until the bottle fills. Bottling wands displace the right amount of liquid, so the beer needs to fill right to the brim, and when the bottling wand is removed the beer volume will be perfect. There may be some spillage, so best not to bottle where you don’t want mess!
Cap the beer with a capper. I tend to do batches, filling 10 or so bottles at a time then capping them. If you can rope a friend in to help then you can get a production line going. If you do it in batches, place the cap on a filled bottle whilst it sits there waiting to get capped.
Step 7: Wait
Mark the bottles so you know what they are. I mark the lid after capping and drying the caps. Then place the bottles somewhere warm enough for the yeast to work. Ideally it would be at around 20°C.
The bottles will take around two weeks to condition to a point ready to drink. The actual carbonation usually happens much quicker, but there’s a fermentation going on which throws out all sorts of weird flavours, and there’ll be strong flavours of diacetyl and other “green” flavours. It can take a bit longer on some occasions, and I find after cold crashing the beer conditioning does take a little longer.
Kveik beer can be conditioned at the same primary fermentation temperature (30-40°C) and the beer should carbonate and be ready to drink much quicker.
Step 8: Drink!
Before drinking the beer, put it in the fridge for a day or two to compact the sediment at the bottom of the bottle. When you pour, leave a couple of centimetres in the bottle so as not to pour sediment into the glass. Enjoy the beer!