Small Boil, Large Loss?

[JayBee]

I`m loving the freedom to experiment I`m having with extract brews after making up kits for 18 months. Ten litre brew lengths are spot on for playing around with and getting recipes sorted and I can get another brew on a few weeks later and try something else without having to see off 23 litres of either very good, indifferent, or pretty poor beer first.
I`m not sure if its a problem or just something annoying me but after starting out with my initial six litre boil ( for one hour ) I`m only ending up with just over four litres left in the pot. Obviously there`s a loss to the hops and evaporation but I seem to be left with less liquid than I expect, even after the occasional top up with boiling water during the boil.
Could the reason be the type of pan I use? I`m using an eleven litre capacity stock pot on the stove which is quite wide rather than tall, if that make sense. Would using a narrower pan help to retain some of the liquor and save making so much up at the end or am I worrying about nothing ?

[OldSpeckledBadger]

Evaporation losses are mostly a function of the vigour of the boil and a vigorous rolling boil is a good thing so I wouldn't worry about it.

[JayBee]

Thanks both. I`ve got another pot thats taller so I`ll try that next weekend and compare the loss with the previous two boils.