Excess Boil-off (Altitude or Temperature? )

[atomicx6637]

The last 2 batches I have brewed I have seen excessive boil off. I started with right around 6G and after a 60 minute boil I was down to about 4G on each. The first batch it was about 15 degrees out and it took considerably long to get to a boil, so I figured that what caused me to lose more on the boil. The last batch have it was between 35-40 during the book and it seemed to be similar time to get to a boil when it was considerably warmer out, so that makes me curious about the temperature. I am in Denver at an elevation around 6000', I want to see if anyone has run into similar issues.

Thank
Troy

 

[woknblues]

Absolutely this happens to me... I also have a pretty wide kettle, 17" diameter, and I am sure that isn't helping.. I just add a bit more to my boil to compensate.