Low-preboil, need help!

[WeissGuy]

Hi guys,

Just gathered my wort and my pre-boil gravity is low. I needed around 1.034 and I have about 1.025. I plan on lengthening the vigor and length of my boil, but can I also add some corn sugar to my boil to increase fermentables? Will this change the flavor of my beer in the end?

 

[WeissGuy]

Brewday ended well, but lo, I am an idiot sometimes. I think the reason my pre-boil gravity was so low is because I was taking hydro readings on very hot (~145F) wort....when I took readings of cooled down wort, it was actually just above my target pre-boil gravity. This was due to the fact that I had added about .6 lb of corn sugar to increase my amount of fermentables. My OG was 1.051 when I pitched my yeast, and my target OG had been 1.043, so I guess my Irish Dry stout is going to have a little more zip to it.