How much 'Boil Off'

[puravida]

I've only ever made beer where I've made a smaller amount fo wort and topped up to full brew length at the end of the boil.
I want to make a small 10L or (2 carboy) wheat beer as an experiment and plan to boil for 60 mins.

I'm using 1kg of wheat malt and 666g of maris otter. Not decided on hops yet. It's an impromptu brew that I may do this afternoon so will be a matter of looking at what I have!

 

[RobWalker]

I do the same. My last batch boiled off pretty much one of the two gallons - topping up resulted in the same gravity as predicted though, only thing that suffers is the correct bitterness - I think. lower volume = more hops needed for same bitterness. not really much wrong with an under-bitter beer though, just makes it easier to drink :p

Beersmith predicts for 2 gallons you need 2.29 gallons, so 0.3gl boil off. Mine really didn't work out like that though, hahah, so I wouldn't be too afraid to top it up a bit during the boil!

 

[Mark1964]

you should be looking at 11 to 15
litres over 90 minutes boil. beer smith has a boil off calculator that will work it out for you

 

[Vossy1]

you should be looking at 11 to 15
litres over 90 minutes boil. beer smith has a boil off calculator that will work it out for you

For a 10ltr batch, is there a decimal point missing :wha:
At 10% per hour anywhere between 1.1 and 1.5ltr would be about right.