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Can anybody else "smell" fruit flies?

So I've done some fairly extensive web research (read: about 5 minutes with Google) that has brought up nothing on this topic, and maybe (my completely forgotten) high school biology would explain this for me, but can anyone else smell a fruit fly when it lands in a glass of wine?

I've been testing myself for a while now, ever since I noticed it: smell wine in kitchen utterly run amuck with fruit flies (it is summer, after all, and all those tomatoes must smell divine to a fruit fly), wait until a fly lands in glass, smell again. A definite, more "fermented-y" smell. Then, pick fly out, wait 5 minutes, smell again.The smell has dissipated and gone back just about to normal. I've smelled this same fruit fly "scent" in my composter; other people in my family have told me I'm crazy and a fruit fly in and of itself has no discernible "smell".

So.... am I crazy? Has anyone smelled the difference in their wine pre-fly and post-fly? Or is this something everyone encounters and the non-believers in my family really are people without good senses of smell (which could actually, possibly be the case.... hmmmm)? I need help.

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  1. You're not crazy. At least not about this.

    Several winemakers have commented on the fruit fly smell. There's an "enzyme," for lack of a better word (actually it may be an enzyme) that fruit flies emit when they're scared or frightened, and that's what you're smelling. Flies and mosquitos are very good at reading carbon dioxide, and even though they're attracted to it, when they smell too much of it, they fly away. The enzyme is dSO, short for drosophila stress odorant, and it's a quick burst of CO2 (among other things) to tell other fruit flies to stay away. Once the fly is out of the glass, the odor is gone too.

    You must have a pretty good sniffer.

    2 Replies
    1. re: maria lorraine

      so, basically, it's fruit fly "sweat".


      thanks for your very informative answer!! i knew somebody here would have a good explanation!

    2. Absolutely - and just one fruit fly can ruin a glass of wine

      1 Reply
      1. re: Sam B

        Obviously you were never judging fruit wines at the LA Co Fair back in the '60s . . .

        1. At work, we describe it as a faintly iodine-like smell. I find that if the fly lands on the glass or on the rim of an opened bottle (even when the cork has been stuck back in the bottle) it noticably mutes the aromas and flavors.

          1. Yes I can most definately smell them as well, I work at a winery and I can smell them flying around an open tank from at least 5 feet away and sometimes up to 10.

            1. I so know what you are talking about and am glad I am not crazy! I always know when a fruit fly has landed in my wine the minute I pick up my glass.

              1. I am SO glad someone brought this subject to our attention. I have noticed, for years, that even ONE tiny fruit fly can change the aroma and taste of wine. Thanks for validating my "discovery"..

                1 Reply
                1. re: vitaminD

                  "fruit flies emit when they're scared or frightened"

                  So are they frightened all the time? How else to explain smelling them in the air 10 feet away or knowing that one has momentarily landed on a glass of wine.

                  Best of all, a fruit fly lands on the mouth rim of a recorcked bottle of wine and ruins the wine sealed inside ["noticably mutes the aromas and flavors."]


                2. I had a glass of Orvieto last night that a fruit fly got into. The smell was disgusting. Glad to know that I'm not alone in smelling this!

                  1. I thought I was insane until I saw this. Thank goodness. It was interesting trying to figure out what to type in Google, "Can you smell a fruit fly dying?"

                    1. I also thought I was the only one. I recently saw a video with Lou Kapcsandy where he claims that five fruit flies can ruin a barrel of wine. This led me to do an internet search. In addition to this thread I found an article that claims fruit flies carry acetobactor but I don't know the details.

                      1. Obviously I am smelling/tasting it too, which prompted me to google the topic. I hate the tainted smell and taste!!! I will be covering my glass from now on.

                        1. Yes! I have found that it's not just wine that can be ruined. If they have the audacity to hang around and target a bowl of fresh fruit, I can always tell when they've found it. I have been known to have a super sniffer, but I'm glad to know I'm not alone in my revulsion to this scent!