Now that everybody else has had a go at trying to confuse this topic, I though I would have a go
First off you need to understand exactly what the "priming" is trying to achieve.
Adding more fermentables after all activity is finished into the bottles is just extending the fermentation in a controlled manner to provide a "known" amount of CO2 into the bottles.
So the actual goal of "priming" is to control the amount of CO2 being produced as part of another fermentation cycle.
As with any fermentation cycle we need to have:
- fermentables
- yeast
- correct temperature
Theses are the parts you need to concentrate on to provide the desired carbonation level. Note the correct amount of fermentables (usually sugar) is what will determine how highly carbonated the resulting beer is.
The fermentables can be anything you want:
- sugar,
- DME,
- fresh wort,
basically anything you can ferment (within the confines of a sealed bottle). I have tried all of the above and they all work.
The yeast as previously mentioned, makes a large determination in how long the carbonation period is going to take. The more yeast you drop out by doing extended carbonations, filtering, fining, cold conditioning etc, and the less healthy the remaining yeast is, the longer it is going to take to carbonate.
Note where I differ from Lamb is that I will focus on getting the beer in the state I want it, and still doing longer fermentation, cold conditioning etc, knowing full well its going to take longer to carbonate.
You can add yeast, and it is common practice for commercial breweries that bottle condition to add a specific "conditioning" yeast for this purpose. Usually one the flocculates out well, and ferments quickly and cleanly at room temperature ( ie a clean lager yeast ).
I sometimes stir back in a small amount of the yeast that has settled on the bottom if I am concerned about the amount left in the beer. This is only really practical if you are bulk priming.
The third part of the equation is temperature. Basically the warmer it is, the quicker it is going to happen. If I want to speed up carbonation (especially during winter) I will create a temp controlled environment that stays about 23C (just a heating device in an non working fridge), most beers will carbonate in this environment within 2-4weeks.
Alright so that is the easy part done, the mechanics of carbonating your beer, now onto the tricker part, the level of carbonation.
Again this mostly comes down to the amount of fermentables ( ie sugar, carbonation drops etc ) that is added when bottling. Now here the temperature that the beer has been fermenting at also comes into play, as different amounts of CO2 are dissolved into solution at different temperatures.
You may have noticed that a lager after fermentation seems to have quite a bit of carbonation, compared to an ale, and this is because the CO2 dissolves more readily at lower temperatures. This means you need less sugar for a lager then you need for an ale to achieve the same level of carbonation.
Note if you are using the predefined measuring spoons or carbonation drops there is not much you can do about this. It can really only be addressed by bulk priming. Again if you don't really care either way, at least you know why your lagers are generally higher carbonated then the ales.
And one final note is the different yeasts, with different attenuation properties will provide slightly different results even if all the other factors are taken into consideration.
Basically dialing an exact level of carbonation is almost impossible to achieve with bottle conditioning,
a ballpark level is achievable,
if you just stick to the carbonation drops etc, it will get there and is usually moderate to high level of carbonation.
I have also attached a spreadsheet to help calculate the amount of sugar to add for bulk priming that takes into account the beers temperature when bottled (inherent CO2 dissolved).
So there you go, quite painless really
View attachment Priming_Sugar_Calculator.xls