How To Bake Brownies With A Perfect Glossy Skin

If you’re anything at all like this writer, you don’t spend a lot of time inspecting brownies past the initial object identification phase, preferring to insert them directly into the mouth post-haste. But those with more of an aesthetic focus take great care to produce brownies with a glossy, attractive skin. [Adam Ragusea] decided to find out what it takes to get a perfect brownie skin, time after time.

After many, many trays of brownies, [Adam], with the assistance of [Dr. Pia Sörensen], determined that the key seems to be making a brownie mixture with very finely dissolved sugar, in sucrose form, with a carefully controlled amount of water in the mixture. This produces a thick mixture which can hold together against the gases bubbling out during the cooking process, and produces a nice glossy skin. Too much water, and the mixture isn’t viscous enough to hold up, leading to brownies full of pock marks, while alternative sugars like fructose and glucose likely disrupt the ordered structure of sucrose molecules necessary for a shiny surface.

Together, [Adam] and [Pia] do a great job of exploring the molecular chemistry behind the process, as well as ruling out several myths that have been perpetuated in the viciously insular brownie subculture. All they’re missing is a set of standardised reflectivity tests executed with an Arduino and some photodiodes, but we’ll assume that was just cut for time. We’ve seen other hacks in the realm of molecular gastronomy before, like this homebrew kitchen centrifuge. Video after the break.

[Thanks to dkt01 for the tip!]

35 thoughts on “How To Bake Brownies With A Perfect Glossy Skin

  1. Hmm. Interesting. I always associated the shiny papery skin with icky factory brownies, and the nice textured top surface with yummy fresh-from-our-own-oven taste. I had no idea shiny skin was a desired feature, but it’s nice to know how it comes about.

    I’ll still pass on it.

    1. I too associate shiny buns of any kind as factory made reheated stuff that generally tends to be less fresh than other buns. Not to mention that a lot of the more glossy baked goods tends to offer more than just surface texture for that shine. Usually ending up with a more dry end product that simply doesn’t taste as good.

      Ie, to me, the glossy surface isn’t an attractive feature in the slightest.

      One can also just dilute “some” sugar in water and coat the buns in that post baking, but that tends to make them a bit sticky, and generally accumulate dust like a magnet… (I don’t know why some people do this, I guess it is for the more glossy surface, yet again a sign of the buns simply not being nice.)

      A shiny bun is like a midrange PC stuffed full of RGB.
      One can either spend effort on looks, or one can spend it on what actually matters.

  2. I usually get that skin from boxed brownies. It’s cool to know these tips for better brownie appearance. When they mention air bubbles my first thought was throw the batter into a vacuum chamber like we see with resin here on HaD.

    1. I don’t think putting brownie batter in a vacuum chamber would have the desired effect. I’m visualizing a brownie about 5mm thick and tough as shoe leather. Bubbles are kind of important in baking.

    1. Well, actually dissolved, it can reach saturation and end up a gritty slurry. So not just wet and in suspension but thoroughly homogenised into the solvent. Might take some gentle heating.

      1. I believe “finely dissolved” means completely dissolved vs partially.. if you let any type of cake/brownie or even pancake mix sit on the counter for a little while the sugar will dissolve more thoroughly, the texture will be smoother and apparently shinier. I never noticed really it being less or more shiny but it’s definitely less gritty and more fluffy with the fully dissolved sugar. The bubbles are from over-mixing so I’m not sure why that was brought up. As long as the top has those nice cracks and bouncy texture with no bubbles, that’s all I’m worried about. Never really thought to myself “gee, I sure hope these brownies are shiny” lol

  3. Okay…What if you added some butter that was slowly cooked for a couple of hours with some finely ground plant material?
    Then maybe whichever way your brownies came out, everything else around would perhaps appear sort of “shiny”.

    1. A friend discovered mortar n pestle with sugar allowed stickier plant products to be neatly incorporated into any baked goods recipe. Muffins benefited quite well from this breakthrough…Zzzzz

  4. I’m glad he figured it out. I knew it had something to do with how the ingredients are mixed but never pinned it down since I don’t often make brownies anymore. Makes sense after having done frostings a few times from scratch, the thing I noticed most was sifting my sugar vastly improved results. To where it felt held together instead of mushy when pressing it but otherwise similar if the sifting wasn’t as meticulous.

    Pretty awesome to find that frosting is actually a thin layer of sugar crystal just barely forming on the surface.

  5. You know, candy bars and chocolate truffles that have glossy surfaces usually get that by including some sort of wax that migrates to the surface. I always assumed that something similar was done with brownies. In any case I’ve never noticed any difference in the eating experience, between “glossy” brownies and ones that look like cake.

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