Three weeks?!

[FirebladeAdam]

I've got two 23 litre ferms going at the mo. One was pitched on the 7th of this month, so 22 days ago. It's still bubbling, which seems a long time. The other slightly longer. It too still burps a bit.
Should I be worried and bottling anyway?

 

[BrewMeHappy]

Did you take a reading with your hydrometer at the start to compare to now? That's the only sure way to know.

If the temp has been on the lowish side it will lengthen the time it takes to brew. I have left one or two brews in the past for 3 or 4 weeks before bottling and they were fine, so you are probably ok still, but I'd be keen to get them finished off if I were you. What temp are you fermenting at?

 

[FirebladeAdam]

No I didn't take a hydrometer reading. It's about 18.5 C where they are.

 

[Gerryjo]

No I didn't take a hydrometer reading. It's about 18.5 C where they are.

Hydrometer checks your sugar levels and conversion to alcohol and a thermometer checks your temperature.
I would assume that you have got them muddled up.

 

[BrewMeHappy]

It's going to be hard to judge without a hydrometer reading. I'd be tempted to try and lift the temp slighty to between 20-22 and see if that helps them along for another week and finish them off.

 

[Richard_H]

Any idea what yeast you used? 18.5 is on the lower end of the scale and some ale yeasts will stall below 18, I suspect if your yeast stalled now then you would really struggle to get it going again after 3 weeks. As above take a hydrometer reading as it might be nearly done anyway and if that's the case I would just leave them where they are.

Unless the kits/recipes had a very high OG target then if the hydrometer reads 1.014+ then I would move them somewhere warmer (20-22) for a week where the yeast should perform faster

 

[AnimatedGIF]

The reason it's best to take a hydrometer reading is because air lock activity is not a good proxy for rate of fermentation. There are a number of reasons the airlock may bubble - fermentation is just one of them.
There's a good video on this in YouTube -