So what is “sugar bloom” then?

Another good question from reader Alicia. Sugar bloom is a different phenomenon, familiar to anyone who’s refrigerated or frozen chocolate for any period of time. Sugar bloom happens when moisture contacts the surface of solid chocolate. When that happens the sugar near the surface of the chocolate dissolves into the water and becomes syrup. In time the water evaporates leaving sugar crystals behind.

The problem is exacerbated when chocolate is repeatedly chilled and warmed. So for instance if you have a large chocolate bar in the refrigerator or freezer and you occasionally take it out to chip a bit off, you get condensation on the chocolate bar when it meets the warm air. When you put the chocolate back in the chill chest the syrup-evaporation thing happens, and the cycle is repeated with every removal. Pretty soon a large proportion of the sugar is drawn out, and because long-term freezing also exacerbates fat bloom, shortly your expensive chocolate bar has the mouthfeel of sidewalk chalk. The same thing happens if you have a habit of leaving the refrigerator or freezer door open for a long period of time.

Thanks for a great question, Alicia!

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16 Responses to So what is “sugar bloom” then?

  1. Sanni says:

    Dear Joe offtopic but I have the Butterkuchen recipe translated and thhe email link isn’t working. Shall I post it in the comment section? Goodday, Sanni

    • joepastry says:

      That’s weird, I’ve been receiving emails all day. Did you try just sending to Otherwise yes, just post it to the comment fields and I’ll get it.

      Cheers and thanks!

      - Joe

  2. ErinElizabeth says:

    Why would you freeze chocolate? My understanding was that the high saturated fat content of the cocoa butter made it really shelf stable. Is there some other aspect that is better preserved in the cold (absent the discussed repeat refrigeration/freezing of course)?

    • joepastry says:

      Some people freeze chocolate if they get too much of it, like at Valentine’s day. Others freeze or refrigerate it because they have hot home or production kitchens and/or live in warm climates and are trying to prevent slight melting and the resulting blooming. It’s not really recommended, however, and no, it really doesn’t do anything to prolong its life.

      Thanks Erin!

      - Joe

      • naomi says:

        Yep, chocolate is back in the pantry currently, but I’ve learned to always refrigerate it in the summer, after picking up a bar and having it sag around my hand. (We’re not big into a/c here.)

        Thanks, Joe, hope your holidays are peacefully wonderful.

        • joepastry says:

          Same to you, Naomi! Santa tells me you deserve an especially good Christmas this year. ;)


          - Joe

  3. Susan says:

    I thought about getting a small electric wine temperature stablizer thingie last summer not only for our wine but for chocolate, too. I live in the SF bay area where it’s mostly mild so we don’t need air con often in summer but temps can vary enough to wreck havoc with chocolate and wine.

    • joepastry says:

      Not a bad idea, Susan. All that sea air can be hell on chocolate. Thanks for the comment!

      - Joe

  4. ascanius1 says:

    More on the cheap chocolate debate. Looks like the evidence is mounting against your thesis that the difference is unimportant.

    Cook’s Illustrated did a test under scientific testing rules. This is the last paragragh in their review:

    “What do we recommend? The more expensive chocolates–Scharffen Berger, Callebaut, Ghirardelli, and Valrhona — were all well liked and received similar scores. If you are willing to buy in bulk by mail, Callebaut turns out to be a best buy. Of the three mass-market brands (Nestle, Baker’s, and Hershey’s), Nestle received more positive comments and significantly higher scores. In fact, there were so many negative comments about Baker’s and Hershey’s that we cannot recommend either chocolate. It’s important to remember, though, that chocolate, much like coffee, is a matter of personal preference, so consider each brand in order to find a chocolate that suits your palate. The gamut of flavors runs from “nutty” and “cherry” to “smoky,” “earthy,” and “spicy.”

    And don’t accuse Cooks Illustrated of foodie bias. They were among the first to say people couldn’t tell the difference between pure and imitation vanilla extract in most baking. It only makes a difference in products like custards and ice creams, where the subtleties aren’t cooked away.

    The pioneer woman did a more informal test with brownies, using scharffen berger vs. bakers vs. a betty crocker boxed mix. she was hoping the cheap bakers chocolate would come out first, debunking the myth of the superiority of superior chocolate. but to her dismay schaffen berger came in first, baker’s chocolate last.

    • joepastry says:

      Hey, A!

      Thanks for that, however my point is not that expensive chocolate has no use, but rather the opposite, that inexpensive chocolate has a use! In fact a lot of them. That’s true no matter what Cook’s Illustrated has to say! ;)

      - Joe

    • joepastry says:

      Remember also that my claim is that inexpensive chocolate can be as good or better than expensive chocolate in or atop things, as an ensemble player. Placed next to one another and sampled in pieces, i.e. eaten as candy, Hershey’s will lose to Vahlrona every time, and for good reason. However there are preparations that can make the most of the flaws of inexpensive stuff, especially for home bakers.

      • ascanius1 says:

        i think all those tests were not just eating the chocolate but eating basic baked products like brownies cooked with the chocolate. serious eats has done a similar test with chocolate chip cookies. and the quality of the chocolate did make a difference. i think it’s because chocolate has such an assertive taste that the difference is more detectable than with vanilla. that’s why for most people cheap chocolate taste will come through as cheap chocolate even atop things.

        • joepastry says:

          That’s probably true. Amazing how so many otherwise intelligent people can be so wrong, isn’t it?

          It’s that very assertiveness you describe that’s the problem with something like a coated cookie or a doughnut. High quality chocolate all but shouts out “I am here!!” instead of blending amicably into the broader flavor and texture profile. I suppose that’s fine for some people, but if the chocolate bits are the only thing you’re interested in, why eat the cookie in the first place? No, I shall not be budged.

          Thanks as always, A!

          - J

          • Catherine says:

            Maybe the cookie part breaks up enough of the richness of the chocolate so that you can eat a lot more of it? ;)

  5. Roger says:

    If all this molten chocolate isn’t going to be used in a particular monument of pastry goodness, I’m going to be sorely disappointed. :)

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