If the water should boil away while it is cooking, add a little more.
Add more water should it boil away or the soup get too thick.
"All the strength of the coffee will boil away," murmured Fico.
A small quantity, such as a half pint, will boil away in twenty-five to thirty minutes.
To make one kettleful of salt we must boil away from thirty to fifty kettlefuls of water.
The water should boil away so as to make a rich gravy, but be careful it does not burn.
Then skim them out, and boil away the syrup half an hour; then pour it, hot, upon the strawberries.
The kettle holds two gallons, and so, in order to get a pint of salt we must boil away two or three kettlefuls of water.
It will boil away fast, therefore see that it does not stand too long.
If all the water were allowed to boil away, a layer of mud or of other impurities would be found at the bottom of the vessel.