Sugar Buzz

Two related comments came in over the weekend in regard to sugar and soda. First this observation from reader Julie:

Another thought on the baking soda: milk heated with acid will curdle every time, and caramelized sugar becomes more acidic as it darkens. I like my caramel reasonably dark, so I’ve run into problems with curdling milk on more than one occaision. I find it also helps to use plain refined white sugar, as a blonde organic sugar (with a little residual molasses left in) will contribute to curdling.

Hey Julie! I’ve never had that happen when making caramel sauce (if that’s what you’re referring to here), but it makes sense. As you point out, dark caramels are acidic, as is molasses. Add heat and dairy and curdling is at least a possibility, especially as the caramel gets darker. Fat will help inhibit that protein bunching, however, so try cream instead or add some butter first. It’s a tough job but somebody’s gotta do it! 😉

Next we have this from reader Jen:

Joe, in making peanut brittle, the sugar syrup mixture turns from being translucent to totally opaque when the baking soda is added. I always find it absolutely fascinating to watch. I presume something similar happens in this recipe? Is that also part of the Maillard reaction or something else? The texture also changes in the peanut brittle because of the baking soda, from stretchy and, caramelly, to a very loose, egg white batter type consistency. Obviously that’s partly due to the foaming action, but is there anything else going on to cause that? And does that happen in this frosting too?

Hey Jen! What’s happening is a leavening reaction. Caramel, as mentioned above, is acidic. So when you add baking soda you get CO2 bubbles. It’s those bubbles that make the peanut brittle opaque, as light rays can no longer pass straight through the caramel. They get bounced around by the bubbles, so the brittle appears creamy.

However color isn’t the main reason most brittle recipes call for soda. It’s the texture change that’s the most important. All those bubbles turn the finished brittle into a foam, which makes it far easier to bite and chew compared to a straight caramel that’s had peanuts added. The bubbles make it both lighter and more rigid, so it shatters and crunches in the mouth…and sticks to teeth a whole lot less.

To answer the other part of your question, some browning reactions may well be occurring in there, since caramel holds heat quite well. Now that you mention it, I recall seeing some very blonde peanut brittle as well as some very dark peanut brittle, it probably has to do with the point at which the candy maker adds the soda. More heat will create more browning.

Lastly, I don’t think there’ll be any leavening reaction in the caramel cake icing. But then I’ll be adding an acidic caramel to a mixture that has baking soda in it…a little something may well go on in there. It hadn’t occurred to me until now, Jen. I’ll keep an eye out! Cheers and thanks for the great questions!

12 thoughts on “Sugar Buzz”

  1. What we call Hokey Pokey is made by adding baking soda to a toffee. It used to be a common thing for kids and Mums to make for fund-raising efforts. When you mix the baking soda into the hot toffee, the whole thing puffs up to ~10 times its original volume and you quickly pour it out so it can set with all the nice big bubbles in it. It’s very exciting when you are small. Cadbury cover it in chocolate and call it Crunchie, and New Zealand ice-cream manufacturers mix small pieces of it in with vanilla ice cream to make the NZ classic Hokey Pokey ice cream. I believe it has different names in different countries.

    1. Interesting. There must be more soda in that than our brittle. Judging from the pictures I just saw it puffs up quite a bit more than our brittle.

      – Joe

        1. I think my girls would love it…the whole thing…the taste the drama, everything. I’ll give it a whirl.

          – Joe

    2. Here in Buffalo NY, it’s called sponge candy, and usually comes cut (or moulded?) into small squares covered in chocolate. It’s apparently something of a local specialty – I hadn’t run into it until I moved here.

      1. Cool! I suspected there was a name for it somewhere. I appreciate the comment, Jane!


        – joe

  2. I noticed that milk curdles when added to caramel, but cream doesn’t. Nice to know why! Another problem though: I sometimes have trouble emulifying the butter into the caramel when I make caramel candy kind of thing. The sugar and the fat just won’t mix, especially when there’s lots of butter. Maybe I should add the butter gradually like making a mayonnaise?

    1. Hey Henry!

      Sometimes it can take a while to get the butter worked in, however if you whisk long enough, you eventually get the emulsion going. I’d think adding the butter a little at a time, as you suggest, would also help.

      Nice to hear from you!

      – Joe

  3. Ohhhh darn it, now I’m craving hokey pokey!
    Do the hokey pokey (hey that’s a dance too, although I’ve never heard it called the hokey “tokey” here in NZ, it’s either cokey or pokey) with your girls, it is fun, almost as much fun as making playdoh on the stove top and playing with while still warm. I wish my kids were little again, I miss those days.

    1. I’m going to have try that again. But take heart, Annemarie, one day there’ll be little kids around again! 😉

      – Joe

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