How Much Wort Will Boil Off? (All Batch Sizes at 30, 60, & 90 Minutes)

Thick Brush Stroke
Thick Brush Stroke
Thick Brush Stroke

Homebrewers can expect to see 1-1.5 gallons of wort boil off per hour. Since most recipes recommend an hour-long boil, you should expect just over a gallon to boil off. 

Factors such as kettle size, burner type, temperature, and humidity will all affect the boil-off rate. 

How much wort boils off while homebrewing beer?

For instance, it will take longer to bring 30 gallons of wort to a boil than five gallons. If brewing outside, homebrewers have to take the temperature and wind into account, as well.  

How much wort boils off in an hour?

Many recipes are written for about a 5 gallon batch of beer. In an hour, just over a gallon of wort will boil off.  

How much wort boils off in 90 minutes?

Expect nearly 2 to 2.5 gallons of wort to boil off in 90 minutes.  For a 5 gallon batch, it is recommended that you start with close to 8 gallons of pre-boil wort. 

How to determine your boil off rate for brewing

In order to determine how much liquid you will need to start with in order to accommodate for the boil-off rate, you can set up an experiment ahead of time using water. 

How vigorous should you boil wort?

With enough headspace to prevent any accidents, the boil should be higher than a simmer but not an out-of-control boil. A consistent, rolling boil is preferred. This is to ensure sterilization of the beer as well as clarity and development of flavors. 

What is the wort boiling temperature?

Wort boils at over 212℉. The exact temperature at which it will reach a boil is determined by the wort’s gravity as well as your elevation.  

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