Boil over on first hops addition

[unviewtiful]

During my brew session yesterday, the first hops addition caused a massive boil over instantly after the hops touched the wort. Using fermcap, I got through the hot break with no boil over and the first hops addition was at 55 min (I was making Biermuncher's Centennial Blonde), so it was clearly the hops that cause the boil over. But I'm curious what in the hops caused such a violent reaction? My logic tells me that the oil in the hops should reduce the surface tension and prevent bubbling, but I'm clearly incorrect. Does anyone have solid insight on causes and prevention methods?

As a frame of reference, I was doing a 10 gallon batch (12.5 gallon boil volume) in a keggle with a banjo burner.

 

[KeninMN]

The hops as as nucleation sites. Here is some excellent information:

http://londonbrews.com/2014/05/09/guest-post-avoiding-a-boil-over-when-home-brewing/

 

[unviewtiful]

The hops as as nucleation sites. Here is some excellent information:

link

Ah, that's a very good point. If that's the case, would whole cone hops act differently in this regard? Fewer large particles as opposed to a ton of tiny particles you get with pellets.

 

[KeninMN]

Apparently not:

https://byo.com/stories/issue/item/341-bubble-bubble-boil-and-trouble

Whole hops don’t cause as much initial foaming, but you still need to add them carefully at the start of the boil. Because it can be more tedious to separate or weigh out whole leaf hop additions, it’s a good idea to have everything ready before you start the boil. It helps to weigh the hops into paper or plastic sandwich bags prior to the brew session. If you don’t have a set of scales, then whole hop plugs are especially handy for getting good hop weight estimates. The plugs can be readily split using a sharp knife.

 

[runkelia]

Not sure the science behind a boil over, but I'll tell you what, turn the heat down when you suspect its starting, and you're good the rest of brew day.

 

[grainbill]

A spray bottle with water in it will knock down the boil pretty fast, unless your heat is way to high. I have also used an additive that Austin Homebrew carries. A few drops in the kettle before the boil and you you won't get the boil over...draw back is that it has a short shelf life.....