Is it just me or does that sound like the name of a town in Ireland? Oh right, it actually is the name of a town in Ireland, a little spot on the northeastern coast where this red seaweed-derived thickener was originally harvested and put to use. It’s been used to thicken puddings and custards in that region since at least 1810. Oh, and in Scotland as well. Locals would boil the local weed to extract the long-chain sugars, add borax to the hot solution to make them clump, then strain the whole mess out and dry it to a powder. The process was steadily improved to the point that in 1930 carrageenan became a mass-market product. It’s been a staple thickener for food makers (and some home cooks) ever since.

Yes, yes, I know some people hate carrageenan so this post is going to irritate them. I’ll say right now that I don’t buy the arguments that it’s poison and I’ll warn potential complainers not to bother sending me emails with links to small-scale independent studies that purport to prove it. They shall bounce off me like so many guided missiles off the meters-thick shell of Esgargantua, the ferocious mutant snail.

Carrageenan comes in three types: iota, kappa and lambda. Each one performs differently as they’re all derived from different seaweeds. I can say that all of them work at about the same concentrations as other hydrocolloids, thicken at both high and low temperatures and form gels that are clear and shiny. Kappa carrageenan forms nice firm gels, but requires potassium ions to work (it is a great gelling agent for milk-based mixtures). Iota forms softer, more elastic gels and needs calcium ions. Lambda is good only for thickening purposes but will act all by itself (it is also especially good for dairy applications). Sometimes they’re used in combination to create different effects. The down side of carrageenans? They don’t play well with acids.

Also, sorry about the picture, I sneezed.

12 thoughts on “Carrageenan”

  1. you know, I think you’re just taking a photo of flour from different angles and pretending it’s all these different things :p

    j/k! Thanks for all this information, I’m enjoying it!

    1. Actually I’m substituting small piles elicit substances for the real thing. The xanthan gum is actually cystal methamphetamine, the cornstarch heroin, the carrageenan cocaine. I forget what all the rest of it is. I must have blacked out.

      – J

  2. Carrageenan is also used in brewing beer, as a clarifying agent. Historically Irish Moss would be used, so carrageenan is just the more refined version. It’s often added during the boiling process, in which case it’s called ‘copper finings’, referring to the big copper vats that were once used to boil wort before fermentation. It attracts positively charged proteins in solution, which allows for flocculation and then finally it all drops out of solution when chilled. 🙂 There has been some recent bashing of the use of carrageenan in brewing; personally, I have absolutely no problem using it, as a brewer. However, it’s an interesting extra tidbit of info, for those who enjoy the occasional tasty brew.

  3. What I really wonder about is how the heck did they get to the point of boiling seaweed and adding borax?

    “Ian, ww ye gonna do wi this seaweed boy-oh?”
    “Ach, Patty, I gwenna berl it up good & dump some 20 mule team inta it!”

  4. Joe,

    Great post. If you want the carrageenan to play well with acid, try adding the acid source last… as the carrageenan solution cools.

    So many of the “complainers” out there have been duped by online rubbish purported to be “science”. Much of it is regurgitated hysteria generated by institutions that actually do no hands-on scientific research of their own, but have set themselves up as self-proclaimed “watchdogs” to guard the best interests of the consumer. A quick look at their salaries tells me otherwise.

    Many of the so-called “studies” referenced are based on very poor experimental design. The continued hype is persistent in its attempts to link carrageenan and inflammation. This in turn allows them to cite carrageenan’s relationship to cancer and is based solely upon the premise that carrageenan can actually come into contact with the human bloodstream. Several past studies indicate that it cannot penetrate the GI barrier. New, extremely intricate and well-designed studies to support these earlier experiments are in the works so stay tuned and thanks for keeping up the positive (and truthful) flow of online information – Kevin

    1. Great stuff, Kevin! Always appreciate it when a real expert weighs in on the issue! Please come back…especially when the study results come in…because I’ll be curious. Cheers,

      – Joe

  5. Can’t help picturing Moxie & Boomer defending the Pastry Clan from the onslaught of Esgargantua.

    1. They’d put up a darn good fight, Cath, between all teeth on the one hand and all the attitude on the other!


      – Joe

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