Low Finishing Gravity

Brewed an All-Grain English IPA, O.G. was 1068. Higher than projected. However, my FG when racking to secondary was about 1006. What factors probably caused this beer to finish this low? Any takers? It should have finished around 1012.

Either really good attenuation or wild yeast. Hopefully the first.

Lower than suggested mash temp?

+1

…or a really long mash time causing an extremely fermentable wort.

Mash time was about 60min. Maybe I should shorten that time a bit? My mash temp was right on at 155 with a pH of 5.3 I did make a one pint yeast starter that seemed very healthy. Thanks for the info…

Have you calibrated your thermometer?

Maybe you measured your OG at a higher temperature. What temp did you take your OG sample? Your hydrometer probably came with a small paper showing how to adjust for the temperature. If you search, you can probably find a temperature adjustment calculator online

60 minute mash time is the norm for most beers. You are good to go here.
For my taste, the mash temp was a little high, but that wouldn’t make you have a low FG. It is the opposite.
The yeast starter did not make your gravity finish that low.

Perhaps your thermometer is off like others have suggested.

I have a digital thermometer. Did not calibrate it. Mash Temp was around 155 at the start and dropped to 151 at the end of mash. I measured my OG at about 70 degrees. Have to look into calibrating my thermometer.

the beer still tastes good, when I racked it to secondary…just a little thin…any other suggestions other than calibrating my thermometer?