This is my first time brewing and I've followed the instructions from a kit. It says to leave the beer in the key for two weeks and its ready when it stops being cloudy. Its now been a little over three weeks and the beer is still cloudy.
What do I do at this point? Can I assume that it's been there long enough and this batch is just going to be a bit cloudy. Or do I leave it longer and wait till it stops being cloudy?
There's a difference between a beer being "Ready" and fermentation being complete.
The only way to make sure fermentation is complete is by checking the gravity. If the gravity hasn't changed for 3 days, then fermentation is complete.
For a beer to be ready, it depends on a lot of factors (e.g. style, ABV, hops, etc)
Considering it's your first batch, I'd just assume it's going to be cloudy. Bottle it, enjoy it, and start the next batch!
The only way to really now is to use a hydrometer to measure gravity. Visual cues are not reliable.
You can consider the beer done when the gravity of the beer has fermented an expect range from the start. To clarify most brewing yeasts will attenuate (lower gravity/sugar content) by 70-75%. So if your beer started at 1.050OG and us now at 1.012 or so, you are likely done. You don't have to hit exactly 1.012 a point or two over or under is also fine. For first time brewers its a good idea to check it one day, then check it again a couple days later to be sure its still not going down. The changing gravity means some sugar is still being consumed.
If you do not have a hydrometer to measure the gravity of the beer, then I'd recommend leaving it in the fermentor for at least two weeks, and try and get it a little warmer (around 70F) for the last couple days to be sure it finishes out.
