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Mar 24, 2009 02:58 PM

Simple Syrup-refrigerate?

Does simple syrup require refrigeration or is it so hypertonic that bacteria won't grow in it?

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  1. Refrigerate your simple syrup.

    You probably don't know the pH of your water- i.e. basic, neutral (probably not, unless it's distilled) or acidic- and that can affect microbial growth along with supersaturation.

    You're thinking of honey, which is antiseptic for a few reasons. From wikipedia:

    Osmotic effect
    Honey is primarily a saturated mixture of two monosaccharides. This mixture has a low water activity; most of the water molecules are associated with the sugars and few remain available for microorganisms, so it is a poor environment for their growth. If water is mixed with honey, it loses its low water activity, and therefore no longer possesses this antimicrobial property.

    The pH of honey is commonly between 3.2 and 4.5.[67] This relatively acidic pH level prevents the growth of many bacteria.

    1. Yes, it needs to be refrigerated. Even in the fridge, it'll eventually grow mold (I know this from experience).

      Interestingly, Trader Joe's sells bottled simple syrup. Just saw this on my last visit. I recently made a rosemary simple syrup to make meyer lemon & rosemary lemonade (Add a splash of Bacardi Limon rum for the grown-ups). :)

      4 Replies
      1. re: lynnlato

        I just made some delicious mint simple syrup that I used in watermelon slushee cocktails with vodka. Delicious. it's in the fridge now, great for making mint ice tea.

        1. re: glenndkessler

          Refrigerate or freeze. I recently spoke to someone who makes up batches of syrup for her hummingbird feeder, and freezes it. Works fine, she said.

          BTW, the red dye is not good for the birds.

          glenndkessler, good idea on the mint. I have an overwhelming amount going to seed, didn't know what to do with it, and someone I will see in the fall loves watermelon with vodka.

          1. re: anonymouse1935

            The ratio recommended on my Droll Yankee hummingbird feeder is 1:5, and I'm tight on freezer space, so I just make enough for two batches. It molds in the feeder quite extravagantly if I neglect it, which ain't good for the birds either.

            The 1:1 syrup we keep for cocktails lasts for at least a month in the fridge.

        2. re: lynnlato

          Did you buy it or just see it at TJs? If bought, what did you think?

        3. I've always left it in a mason jar in the cupboard, and use as needed.

          1. 2:1 simple syrup is more shelf-stable than 1:1, and 2:1 that adds an ounce of vodka per pint of syrup is more shelf-stable still.

            Note that I said MORE shelf-stable: if you've got it around for months, even a 2:1 simple syrup with vodka will go off. But you shouldn't make so much that you have it around that long in the first place.

            1 Reply
            1. re: Jenny Ondioline

              I use to make my SS using a 1:1 ratio and still would get whispy mold like threads when stored in the fridge. I bumped it to a 2:1 ratio and have not had the problem since.