Wyeast 1098 - 69% attenuation

I'm not freaking out, or being anal, just looking at my system and wondering how to get a little more attenuation next time.

Batch size: 6.25 gallons
Starting gravity: 1.052
Final gravity: 1.016
Starter: 1# DME in 4 quarts water

I pitched directly onto the starter. Fermentation took off like a rocket, and has been at 1.016 for 3 straight days. Wyeast has 73-75% attenuation.

Should I have made a bigger starter? This is also an extract recipe.

That's pretty big starter for 1052. Maybe a gentle rock and a few degrees up in temperature. You're just about to predicted FG anyway so I wouldn't be too concerned, and you don't seem to be.

For next time maybe try a slightly higher temp, unless you were up at the upper limit already.

I'm not worried because I am within the style guidelines, I was just a little curious. Using a similar method with an AG with 1056 I got like 80% attenuation.

Look into the concept of "apparent" attenuation.

It's still 1.016, yet the fermenter is releasing GIANT amount of CO2 still. I'm just curious if this is just the yeast still cleaning up their dirty work?

Different extracts have different fermentability. I would suggest looking for a more fermentable extract.

When I use extract (which isn't often) I find dry extract works much better for me than liquid.