Stuck fermentation????

I need advice please!
I just brewed a batch of Evil Twin, extract, Wyeast 1056. I just pitched the smack pack, no starter.  OG was 1.071 and I had active fermentation yesterday but when I got home today no bubbling. took a sample and it was 1.023. Did I under pitch? Should I pitch another smack pack to finish fermentation?
Thanks

give it a good shake and leave it alone for a few days to see what it does. Airlock activity or lack of is not a sign of fermentation.  Rule of thumb is 7 days Primary, 7 days Secondary.. If your not going to Secondary then 14+  days in Primary.

Rule of thumb is 7 days Primary, 7 days Secondary..

Click to expand...

For an average ale. This one has a high OG, so I'd give it more time. Two weeks in primary won't hurt.

I looked up the yeast and it has an attenuation of 73 - 77%

That means one should expect a final gravity from 1.016 to 1.019 from an OG of 1.071. In my experience extract finishes slightly higher.

It may drop a little more. It could be done.

More info about your recipe would be helpful. If you're using dark LME you'll often lose some fermentability. If you did use dark LME, it may be done. I've had similar results until I switched to light LME and focused on specialty grains to provide color and flavor.

Try oxygenation/give it a good shake and wait for an extra week.
What about slightly raising your temperature for 2-3 days and than back to your original temp?
Regards,
Slurk

I know this response is too late to help the OP, but having just used the 1056 smack pack this week myself,  1 package without a starter is definitely a low amount of yeast to pitch for a 1.071 OG.  It says right on the smack pack something like "enough yeast for up to 1.060 starting gravity.

The beer I made this week was only a 1.056 and even then I used two packages of yeast because both Mr. Malty's website and BeerSmith called for it.