DB Alpaca Silk okay for hat?

Hi everyone,
This is my first time to this forum, although I’ve appreciated the amazing videos before! I’m from SW Ontario, Canada.
I’ve got my eye on a hat pattern in the book [I]Modular Knits[/I] by Iris Schreier (great book, BTW). I started my gauge with some Koigu which as it turns out is too light of a wool so I went to my LYS yesterday and bought some Debbie Bliss Alpaca Silk.
My gauge was perfect so I started to knit my hat on round needles. After about ten rows I realized that when I put it down at one point and picked it back up, I had twisted it so decided to tear it out and start over. :frog:
So, finally, to my question…when I took it off the needles, it stretched out wide enough to fit around my waist, rather than my head! Should I not use Alpaca Silk for a hat?

I am not the best at this but as far as I know neither alpaca and silk are elastic so I don’t know that the blend will hold it’s shape and hug your head so to speak like wool would.

When you only have a few rows and take them off the needles, it looks huge because there’s nothing keeping them together. If you used the right size needles and number of sts needed, you should have the right size.