After three attempts, I have a recipe that is very close to New Belgium Fat Tire. I believe my beer is very close to the original. Color, hop, mouthfeel, clarity, taste.
I would say the slight difference in taste is due to the house yeast strain for New Belgium.
When Fat Tire warms up it gives a bready note, which wlp001 just doesn't have.
I used WLP005 and WLP001 in my trials. WLP005 actually makes a better beer than WLP001, but it is all wrong for Fat Tire. WLP001 is cleaner than New Belgium's yeast. New Belgium strain leaves a bread note in the finish which I believe is not attributed to malt grist.
I may try the following yeast in the following trials:
In the meantime, come over to the brewery and enjoy