Halted fermentation

Hi I am fermenting a robust porter as my first beer and after 2 weeks, fermentation has halted, no more bubbles in the airlock. I did an ABV test and it came out to 4%. The recipe stated it should be around 6.5% but the beer itself tastes great. It had been fermenting in the past two weeks with visible bubbles. I also did not use a starter, just a vial of WLP001 yeast. Does this mean it has fermented all that it can? Should I start bottling?

 

How about giving us the expected OG, the expected FG, and the actual hydrometer reading you got. That will tell us a lot more about the beer you have and let us give suggestions based on that. It's probably done but it also could be a stuck fermentation and bottling that now could lead to bottle bombs.

 

On the one hand it is most likely finished with it's primary fermentation and you could bottle it. I will say, though, that in the future you really should take a hydrometer reading to determine original gravity once you put the wort into the fermenter (and before pitching the yeast). Jot this number down on your notes. When you get to the point where you're at now you can take another hydrometer reading, then another in say three days. If the readings are the same you can be relatively sure that fermentation is complete and you can compare the number (final gravity) to the original gravity to determine ABV and attenuation of the yeast. At that point you could bottle and I understand that it is probably very tempting to get that sucker in the bottle, carbonate it, and enjoy your first creation, however with a beer like a porter it will improve the beer by being patient and allowing it to condition by either leaving it in the fermenter for a while longer or bottle it and let it condition in the bottle. I think if you determine that fermentation is complete so you dont have bottle bombs on your hands, then go ahead and bottle it. What you can do is to let it carb up in the bottle and then as a learning experience drink the beers over a periodic time table. You'll find that the beers you are able to store without drinking early (hard to do sometimes!!!) will be be much better in flavor than the "green" ones that you try early on. Good luck and whatever you choose enjoy your first!

 

Did you do your testing with a hydrometer or a refractometer?

 

Expected OG was 1.064 and my OG was 1.094. I took a reading of 1.020 for FG. I calculated alcohol to 9.1% abv which seems off from the reading I took 3 days ago that gave me 4% abv. I used a hydrometer for these readings. Still no visible bubbles in airlock so I am not sure if fermentation is still taking place.

 

If it's an extract batch and your volume is correct, you can disregard the 1.094 OG reading. It's just not possible with an extract recipe at the right volume. What happens is that the extract isn't 100% mixed in the water, making the reading off one way or another.

If the OG was 1.064 and the FG at 1.020, your ABV is 5.9%

Under-attenuation is sometimes an issue if you don't pitch enough yeast. In your case, one vial in a 1.064 beer was less than half the recommended cell count even if the vial was super-fresh. 1.020 is likely going to be as low as it goes.

 

O.G. Minus FG multiplied by 131 will give abv


Sent from my iPhone using Home Brew