Define Rolling Boil
The guys from Brew Strong, Jamil Zainasheff and John Palmer, have frequently referred to a “vigorous/rolling boil” followed by some descriptors to help clarify what it looks like. I wanted to find a visual of what they were talking about to define rolling boil, but all I could find were images of water boiling, which didn’t really help.
Here is a humble submission to the world of homebrewing. I’ve created a short video with some easy terms and definitions of the different levels of a boil. They range from level 1 to level 5. The idea is that if more people use these same terms, we’ll all be on the same page discussing the look of a boil without actually seeing it.
You can also see some animated images below the video to define rolling boil.
Level 1: Simmer
- Occasional tiny bubbles breaking the surface
- Occasional surface deformations
Level 2: Slow Boil
- Dense tiny white bubbles coming up with deformations
- Frequent surface deformations
Level 3: Rolling Boil
- Constant tiny white bubbles causing surface deformations
- Momentary bubble ring around surface deformations
Level 4: Vigorous Boil
- Tiny white bubbles appear all over, not just under deformations
- Constant simultaneous surface deformations
Level 5: Violent Boil
- Bubbles break the entire surface
- Surface deformations occur under previous deformations
- Deformations are violent eruptions
Boil Over
- Violent eruptions produce persistent foam
- Foam covers the entire surface
- Foam and eruptions overflow the kettle
Prevention
- Reduce heat
- Stir away surface foam
- Mist cold water on the surface foam with a spray bottle
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2 responses to “Levels of Boiling Wort – Visual Reference for Homebrewers”
Very useful and definitive images.
Thanks, Dennis!