I have a question about the recipe "Bill Smith's Atlantic Beach Pie" from Genius Recipes. Turns out my pie pan is 9.5 inches, will my pie just be a bit shallow?
Yes, I'm guessing by about 20-25%.
The crust will be a bit thinner as the same amount of dough needs to be spread out over a larger surface area, but since it is not a dough that you have to roll out, the handling shouldn't be particularly tricky. You might consider not filling the pie tin with the crust covering the lip or compensating by using more whipped cream to hide the gap.
Finally, it may bake faster; I'd start checking at the 10 minute mark.
I'd say the difference would be larger, not far from half again as big (you can't calculate exactly because of the shape)- you really need to adjust the recipe
An 8" pie pan holds about 4 cups liquid. A 9" holds 5 cups. The .5 additional inch of yours increases the volume even a little more.
If I were you, I'd go buy an 8". If you don't increase the recipe, the pie filling will be very thin. If you do increase it, it will be awkward because of the can of evaporated milk. You could increase it by 25% if you don't mind a leftover partial can of evaporated milk.
You could make Thai iced tea with the leftover milk.
Not so little as all that- area's a square function; a 9.5" circle is 11.4% larger than a 9"- because of the taper of the side, the volume would be slightly more difference than that.
I've baked many pies in my days both professionally and for family and friends. I personally found the .5" difference to not matter enough to increase the recipe. The 25% increase would suffice imo. That has been my experience.