roiling and broiling

A few days ago, I read Better Half a bit of something I'd been writing about cooking terms, and my mention of a roiling boil completely flummoxed him. Not sure whether I'd stumbled on a dialectal difference or whether BH just had a poor vocabulary when it came to cooking, I asked my boss, a historical linguist who also professed ignorance of the word roil. So, dialectal difference then--BH's vocabulary is vindicated!

To roil is to move water so that whatever is in it (sediment, etc.) gets stirred up. By metaphorical extension, it can mean to perturb or upset. A roiling boil, then, is the type where your eggs knock against your pan.

OED's first citation of roil is from 1590, but most citations past 1700 are American. The origin is obscure, possibly from a rare French verb. Development of the adjective roiling seems particularly American, with the first citation in 1967.

It's a common enough word in American recipes, with an estimated 9300+ Google hits for roiling boil:

To purify questionable water, bring it to a roiling boil and keep it there for 10 minutes at least.

Bring to a roiling boil, reduce to simmer and cook until the meat is tender...

The sea and emotions frequently roil as well.

The British equivalent for roiling boil is fast boil [updated link].

The lack of roiling boil in BrE reminds me of another American -oil word, broil.

Playing Scrabble recently, my opponent The Postman was unsure of broiled, but played it figuring that it must be related to embroiled. This reminded me of one of the first times I watched "Who wants to be a millionaire?" in the UK. The million pound question was (approximately, from memory):

The American word broil means:
(a) bake (b) boil (c) grill (d) braise

I could've won a million pounds, except that I probably would've wiped out on a cricket question long before getting to the mil.


  1. I'm not unfamiliar with the term "roiling boil", but I grew up calling it a "rolling boil".

  2. I wonder if one of these is earlier and the other a folk etymology?

  3. "roiling boil" = 10.1 k Ghits

    "rolling boil" = 320 k Ghits

    I've always heard it as "rolling boil" as well. (AmE, mostly West and Midwest)

    1. I'm a Midwesterner and have ALWAYS used roiling boil (as did my family)and am on this site to satisfy my frustration with those who do not! aarrgghh!

  4. I suspect that "roiling" may be a portmanteau of "rolling" and "boiling", as I've never heard it (TX+VA) despiting having heard "roil" == "rile".

    Broil derives from French "brûle", which is itself a portmanteau of a Frankish word meaning "burn" (probably brennjan) and native Latin usuler.

  5. My wife(TX+KS) points out that "rile" -- which we are familiar with -- derives from "roil", which we'd never heard. She wonders whether "roil" in the sense of stir has become obsolete.

  6. I've never heard "full boil" (Kent, UK) -- I've always used "rolling boil".

    The OED has "rolling boil" as a phrase, and gives "Heaving, surging, swelling" as one meaning of "rolling"; it doesn't mention "roiling boil", but it does give "peturb, disquiet, disorder" to "move in a confused or turbulent manner" as US dialect meanings of "roil".

    I'd guess "rolling boil" is the earlier meaning, and "roiling boil" came around through influences from similar meanings of "broil" and "roil".

  7. Seconding (thirding, etc) 'rolling boil,' but I would also note that my family has two useful terms for two stages before that:

    ** 'thinking about boiling' -- when you can see lots of tiny bubbles stuck to the sides and bottom, but it's not actually boiling yet

    ** 'talking about boiling' -- visually very similar to last stage, but you can hear a rustly/ticking noise that implies it's about to start boiling anytime, really, once it gets around to it.

  8. Have the British really lost the verb broil? I'm amazed. Just 150 years ago, Lewis Carroll defined his word brillig in "Jabberwocky" as "four o'clock in the afternoon -- the time when you begin broiling things for dinner."

    On the other hand, that sense of dinner probably sounds quite American now outside formal contexts, eh?

  9. Visiting years later, as this post has just been revived via Twitter...Put me down for "rolling boil" as well (Californian parents, raised in the south and midwest), but I've certainly heard "roil" in other contexts--usually related to the sea.

    John Cowan's historical note is interesting.

  10. @John Cowan - I would disagree that BrE has lost the word 'broil' - it does seem to be becoming less common tho. In my family (BrE) we have always distinguished between 'grill' and 'broil' tho - a grill was a barbeque and one to grill something was to cook it on a rack with heat from below, whereas a broiler is part of a cooker (US stove), and cooks things using heat from above.

    (And I also go with 'rolling boil')

  11. This comment has been removed by the author.

  12. And I am with my fellow Kentish Man (or perhaps Man of Kent) Adam Sampson -- for me, "rolling boil" is the norm, and "roiling boil" something of which I have never heard but which I would assume to be a fanciful creation or a Malapropism. "Broil", for me, is a pure Americanism, to be replaced with "grill" (as in "from above", and therefore the opposite of "[to] barbecue") in British English.

  13. Heard and used "roiling boil" (TX+AR) all my life (several decades so far). Came across "rolling boil" for the very first time today and assumed it was some sort of eggcorn. I've heard of both rolling waves and roiling seas, so assumed the one referring to bubbling (roiling) was appropriate for boiling water.

    I've never considered the origins of broil (where very high heat comes from above), but it is certainly used apart from grill (where the heat, usually flame, comes from below) in the United States.

  14. BrE. The term rolling boil is very common in the chemistry literature, particularly in papers dealing with synthetic chemistry. It used to be common (and perhaps still us) to use glass “boiling beads” to suppress over-violent roiling.

    1. Scotch-irish background but grew up in canada. Always heard roiling boil from the family but my wife uses rolling boil. English is an evolutive language so both are equally right it seems

  15. My mother was Irish and said roiling boil.


The book!

View by topic



AmE = American English
BrE = British English
OED = Oxford English Dictionary (online)