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Apr 7, 2013 01:51 PM

Steamed clams - juice turned a strange blue-ish color

I just picked up some fresh littlenecks from the farmers market yesterday (they are from Long Island). I steamed the clams in some wine in a stainless steel saute pan, and removed the clams as they opened. After all the clams were opened, I let the juice reduce down a bit for a few minutes. The strange thing is that the juice turned a weird, blue-ish type color. The juice tastes great and the clams are fresh, but the color is unappetizing. Anyone know why this would be? And can I still eat the clams?

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  1. You better wait til someone more intelligent than I am chimes in, but my first guess is it's the sulfites in the wine that are turning the juice blue.

    1. Did you have garlic in there? I've had a blue coloring issue with raw garlic and wine in the past.

      4 Replies
      1. re: Terrie H.

        Usually the garlic itself will turn blue. I've had that happen. Never the liquid, though.

        1. re: C. Hamster

          Very true, though I thought it might leach into the liquid, depending on what was going on.

          1. re: C. Hamster

            Yes to both, and I think it's b/c of the sulfur in the garlic. This may be an old wives' tale....but I'm wondering if there was sulfur/sulfites sufficient to turn it blue in the wine? I don't know enough about wine chemicals to say. And yes, maybe the garlic leached too.


            1. re: pinehurst

              The only thing is that winegod didn't say there was garlic in his pot, and I was asking if there was, just as a theory. Guess more info and then input from our chemically-knowledgeable cooks is needed.

              Completely OT, but I'm picturing a scene from Bridget Jones' Diary where she attempts to cook something wrapped in blue string and turns her whole dish an eerie blue color. ;o))

        2. There was nothing in the pan besides wine and the clams.

          1. Winegod...
            I don't know if this post might help. I'm sleuthing with you!


            1 Reply
            1. re: pinehurst

              Pinehurst - this seems like the closest to an answer that I've seen (in the link Jruckel explains that the blue color comes from a chemical change when scallops are spawning, so I assume there could be a similar process with clams - they are both bivalves, after all). A google search returned nothing in terms of any clues. I hate wasting food and feel bad throwing them out, but the clams just look so unappetizing sitting in this weird, blue liquor. I will have to ask the fish monger at the Farmers Market why this happened. By the way, I have bought a variety of fish and shellfish from this purveyor, and the product has always been of the utmost quality.

            2. The reaction is due to a defense mechanism -- an enzyme -- that is released in the garlic when it is chopped. It reacts with sulfur compounds and amino acids in the garlic, and turns blue. The blue compound is isoalliin, and there is more potential for it in young garlic, the reason garlic bulbs are often stored for two weeks before going to market.

              Here's the scientific notation:
              "The discoloration is due to pigments that form between sulfur compounds in garlic and amino acids. When the garlic tissue is disrupted, as happens in processing, an enzyme is liberated and reacts with it to form thiosulfinates compounds that then react with the natural amino acids in the garlic to form blue pigments. The age of garlic determines how much isoalliin there is in the first place, and the nature of the processing determines how much enzyme is liberated."

              Identification of Two Novel Pigment Precursors and a Reddish-Purple Pigment Involved in the Blue-Green Discoloration of Onion and Garlic, Journal of Agricultural and Food Chemistry, 2006, 54 (3), pp 843–847 DOI: Publication Date (Web): January 12, 2006.

              2 Replies
              1. re: maria lorraine

                I thought there was no garlic in the pot, only clams and wine.

                1. re: alkapal

                  Oops. My bad. No garlic, Winegod?

                  Then my second guess has to do with the pigment cells in a clam's shell, and that the pigment is alcohol-soluble. I think the pigment cells are called iridophores.