Partial Volume Boil – Boiling a concentrated wort and diluting with water after the boil to reach full volume
Pros -
Boils can easily be done on a stove top
Can be done in 3-4 gallon kettle
Reduces the amount of time needed to bring to a boil
Wort chilling times reduced with less volume
Cons -
Concentrated wort reduces hop extraction efficiency, more hops are needed to reach bitterness levels of full wort boil(approx. 10-25%)
Boil overs can be more difficult to clean up
Increased wort darkening occurs in concentrated wort boils
All grain brewing requires a full wort boil
Full Volume Boil – Starting with 6 or more gallons and boiling down to a 5 gallon batch size
Pros -
Increased hop utilization over partial volume boil
less wort darkening
Ability to brew all grain batches
Cons -
Can be difficult to boil 5+ gallons on stove
Requires 7.5+ gallon kettle
May require alternative heat source
Additional chill time or use of wort chiller needed
Increased time to bring to a boil