2 weeks, still bubbling....

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Jeffthedogguy

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Hello! Im new here, I hope im doing this correctly.
I've got a 5 gallon batch of porter that is still fermenting (still bubbling) over 2 weeks after brew day. Is this normal or do I have a problem?
 

Yooper

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Airlocks can bubble for a variety of reasons that aren't necessarily fermentation, like a temperature change or a change in barometric pressure. It is likely done after two weeks, but the only way to know for sure is to take a hydrometer reading.
 
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Jeffthedogguy

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My original gravity was right what the recipe called for 1.065. Now it's 1.036 15 days later. Guess I'll take it for a few days and see if it's steady. No idea what it's supposed to bottom out at...
 

day_trippr

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Prototypical American porter FGs are in the 12 to 18 point range, so this batch is lagging badly.
Some details on the brewing and pitching might be helpful to understand why...

Cheers!
 
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Jeffthedogguy

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I just brew extract kits, this one is a kit from morebeer. I brewed according to the recipe. I can tell you all that if it's helpful. I used my new immersion chiller for the first time with this batch. The liquid yeast pack was really about to burst when I pitched it. The airlock blew off twice in the first 48 hrs. It was a very aggressive fermentation for the first week...
 
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Jeffthedogguy

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One other thing, I had a 5oz bag of priming sugar I had no use for, so I tossed that in also
He's a pic of the ingredients
 

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camonick

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Now it's 1.036 15 days later.
What instrument are you using to get this number? If it’s a refractometer, you need to use a conversion chart to get the correct reading as they don’t work properly when alcohol is present. If you’re using a hydrometer, there is something else going on.
 
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Jeffthedogguy

Jeffthedogguy

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I got a refractometer thinking it would replace my hydrometer. I just started using it for ther last few batches. Maybe that's why my numbers aren't making sense. I thought I could use it before and after fermentation. I'll go take a hydrometer reading in the morning.
 

VikeMan

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Can I just open the valve and let a bit out without causing sanitation problems?

What valve, and what do you want to let out a bit of? Your beer has finished attenuation. To be sure, you can take another refractometer reading now and if it hasn't changed, it's done.
 
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Jeffthedogguy

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I was referring to the valve at the bottom of my bucket fermenter. I'm always worried about sanitation.
I'm sorry but I dont know what it means to have finished attenuation.
I took a hydrometer reading, and I think it looks good. Maybe 1.016 or so?

I really appreciate all the input from you folks. This platform is amazing. I've drifted in and out of my brewing hobby for probably 25 years. My only complaint over the years was the limited information and help I could find. Thank you all very much
 
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Jeffthedogguy

Jeffthedogguy

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Here's my reading...
 

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VikeMan

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I was referring to the valve at the bottom of my bucket fermenter. I'm always worried about sanitation.
I'm sorry but I dont know what it means to have finished attenuation.

Attenuation is conversion of sugars into alcohol and CO2. So finished attenuation means that all of the sugars that will be used by the yeast already have been used.

I took a hydrometer reading, and I think it looks good. Maybe 1.016 or so?

Most likely. Take a couple drops from that sample and measure with your refractometer. If it's the same as a couple days ago, it's finished.
 
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Jeffthedogguy

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It still seems strange to me that this batch is still bubbling(barely, but maybe every 30-60 secs) 16 days later. I have a batch of Irish red sitting right next to it that finished bubbling in 3 or 4 days.
 

VikeMan

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It still seems strange to me that this batch is still bubbling(barely, but maybe every 30-60 secs) 16 days later. I have a batch of Irish red sitting right next to it that finished bubbling in 3 or 4 days.

Counting bubbles leads to madness*. Trust the gravity measurements.

*ETA: It could be something as simple as a tighter seal on the batch that stopped bubbling sooner. But you can never really know that with much accuracy.

Further Edit: Yikes. I meant to say a tighter seal on the batch that bubbled longer.
 
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Jeffthedogguy

Jeffthedogguy

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Counting bubbles leads to madness*. Trust the gravity measurements.

*ETA: It could be something as simple as a tighter seal on the batch that stopped bubbling sooner. But you can never really know that with much accuracy.
🤣 madness indeed! Thank you!
 

1HW

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Specific gravity is a measure of how dense your wort is. It's used to calculate the percent alcohol content of your beer (ABV) and helps us understand when our beer is done fermenting. Original/Starting Gravity (OG) is your wort's "potential" to become alcohol. Higher OGs mean higher possible ABVs. Final Gravity (FG) is the specific gravity achieved when the yeast are done doing their thing. The difference between OG and FG is used to calculate ABV. FG is also an important indicator of how well the yeast metabolized the sugars in your wort. If the number is too high, your beer will be unbalanced (i.e., overly sweet/malty because some of the sugars that were destined to become alcohol were not converted). When you see others using the term "attenuation", they are referring to how well the yeast did its job of converting sugars to alcohol and the CO2 bubbles we love to count.

The folks on this site are very good in helping new brewers identify why your OG may have been too low for a given recipe or why a FG may have been too high (incomplete attenuation). With respect to this latter point, it's important to know how people measure specific gravity. To follow up on what others noted, there is a difference between measuring your specific gravity with a hydrometer (a direct measure of specific gravity) versus a refractometer (which indirectly estimates specific gravity using light refraction). If you have both devices (and use them both), what you will see is that they are pretty close in their readings of OG (e.g., 1.048 vs. 1.050). At the end of fermentation, however, the measurements will be quite different (e.g., 1.016 [hydrometer] vs. 1.036 [refractometer]).

That's a big difference. One that makes you either do a happy dance (if you measured with a hydrometer) or panic that your fermentation didn't finish (if you measured with a refractometer). What gives? Well, in addition to sugars, your wort now has alcohol in it, and the alcohol changes the accuracy of the refractometer as a tool to measure specific gravity. Fortunately for us, others have worked out the equations to correct your FG.

Here's a particularly popular tool for performing the calculations for refractometer readings. Note, it wants the values as Brix (not specific gravity). There's a conversion calculator for that too.

In your example, you started at 1.065 (15.9 Brix) and ended at 1.036 (9 Brix) on the refractometer. Using the calculator, that equates to 1.017 as @camonick noted above and matches what you measured with your hydrometer (1.016). Approximately 5.7% ABV.

Note... 1.036 FG on the refractometer does not always equal 1.017 when converted. You need to perform the calculation each time because the conversion depends on your OG. For example, if you have a high OG of 1.090 (Brix: 21.6 ) then a FG of 1.036 on the refractometer would correspond to 1.008. Conversely, if you were brewing a session IPA with an OG of 1.045 (Brix: 11.2), then a FG of 1.036 would correspond to 1.022. In the first example, there is more alcohol in the sample (10.1%) and this skews the refractometer reading more (it's off by 28 points) than the lower alcohol session beer (2.6% ABV; refractometer reading is off by 14 points).
 
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Stonehenge360

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+1 on all comments so far. Only other thing I would add is if you are really worried about it, there’s no harm in leaving it for another week in the fermentor just to be sure. If your FG has not moved in multiple days of readings you are good to go
 
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Jeffthedogguy

Jeffthedogguy

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Specific gravity is a measure of how dense your wort is. It's used to calculate the percent alcohol content of your beer (ABV) and helps us understand when our beer is done fermenting. Original/Starting Gravity (OG) is your wort's "potential" to become alcohol. Higher OGs mean higher possible ABVs. Final Gravity (FG) is the specific gravity achieved when the yeast are done doing their thing. The difference between OG and FG is used to calculate ABV. FG is also an important indicator of how well the yeast metabolized the sugars in your wort. If the number is too high, your beer will be unbalanced (i.e., overly sweet/malty because some of the sugars that were destined to become alcohol were not converted). When you see others using the term "attenuation", they are referring to how well the yeast did its job of converting sugars to alcohol and the CO2 bubbles we love to count.

The folks on this site are very good in helping new brewers identify why your OG may have been too low for a given recipe or why a FG may have been too high (incomplete attenuation). With respect to this latter point, it's important to know how people measure specific gravity. To follow up on what others noted, there is a difference between measuring your specific gravity with a hydrometer (a direct measure of specific gravity) versus a refractometer (which indirectly estimates specific gravity using light refraction). If you have both devices (and use them both), what you will see is that they are pretty close in their readings of OG (e.g., 1.048 vs. 1.050). At the end of fermentation, however, the measurements will be quite different (e.g., 1.016 [hydrometer] vs. 1.036 [refractometer]).

That's a big difference. One that makes you either do a happy dance (if you measured with a hydrometer) or panic that your fermentation didn't finish (if you measured with a refractometer). What gives? Well, in addition to sugars, your wort now has alcohol in it, and the alcohol changes the accuracy of the refractometer as a tool to measure specific gravity. Fortunately for us, others have worked out the equations to correct your FG.

Here's a particularly popular tool for performing the calculations for refractometer readings. Note, it wants the values as Brix (not specific gravity). There's a conversion calculator for that too.

In your example, you started at 1.065 (15.9 Brix) and ended at 1.036 (9 Brix) on the refractometer. Using the calculator, that equates to 1.017 as @camonick noted above and matches what you measured with your hydrometer (1.016). Approximately 5.7% ABV.

Note... 1.036 FG on the refractometer does not always equal 1.017 when converted. You need to perform the calculation each time because the conversion depends on your OG. For example, if you have a high OG of 1.090 (Brix: 21.6 ) then a FG 1.036 would correspond to 1.008. Conversely, if you were brewing a Session IPA with an OG of 1.045 (Brix: 11.2), then a FG of 1.036 would correspond to 1.022. In the first example, there is more alcohol in the sample (10.1%) and this skews the refractometer reading more (it's off by 28 points) than the lower alcohol session beer (2.6% ABV; refractometer reading is off by 14 points).
Thank you for such comprehensive information. I feel like I just walked into a brewing university with a 20/1 ratio of instructor to student!
 
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