Nougat Science


You can now purchase my handmade candy bars and marshmallows at http://www.bonbonbar.com/
I’ve been battling a bit with nougat this week, and this post is going to go into quite a few corners of confectionery esoterica — into the areas of boiling sugar and using glucose. I can only imagine that Alton Brown would be riveted…

Nougats such as Montelimar and torrone are traditionally honey-flavored confections made by whipping boiled sugar/honey/glucose/corn syrup-based syrup into egg whites. Nuts and dried fruit are often mixed in for flavoring and texture. (Side note: whipping sugar syrup into egg whites is also a technique used to make Italian buttercream frostings and some kinds of marshmallows; the differences lie in the temperature that the syrup is boiled to, the ratio of sugar syrup to egg whites, and what else is added– lots of butter for the frosting and corn syrup or glucose/gelatin/vanilla extract for marshmallows).

Anyone who’s eaten a Snickers, Three Musketeers, or Milky Way knows that those nougats have nothing to do with honey or chopped fruit. And I’m okay with that… b/c I’ve been aiming for a fruit puree-based nougat and a mint nougat. I want my nougat to be flavorful and fluffy without being too chewy, and I’ve had these criteria in mind:

  • I want my nougat to be free of high fructose corn syrup, so I’m avoiding Karo corn syrup. Glucose is my substitute of choice b/c it doesn’t taste too sweet, it doesn’t contain high-fructose corn syrup, it doesn’t attract too much moisture, it inhibits crystallization like other liquid sugars, and it’s relatively inexpensive. Glucose has an industrial-sounding name, but it’s just a molecular form of sugar that can be derived from corn, wheat, and other substances; one tub of glucose that I had listed one ingredient: corn syrup. Granulated sugar is sucrose, which is a disaccharide composed of glucose and fructose. So while Karo goes the (high) fructose way, I go the glucose way. For some reason that I wonder about, glucose is not commonly found in stores. If you’ve never used it, know that it’s extremely thick and sticky — much more so than honey or corn syrup. Consider that this means that it contains less moisture than honey or corn syrup.
  • I want it to taste like fruit or mint, not like sugar or honey.
  • I want the flavors to taste fresh, so I don’t want to use fruit or mint flavor extracts. The mint nougat should contain some form of mint leaf. The fruit nougat should be made from fruit, either juice or peel.

And you know what? I haven’t found a single recipe online or in cookbooks that has met my criteria. That’s fine, since, of course, I am developing my own recipes, but I have to start somewhere, so I’ve been looking to adapt recipes. Usually, what I have to do is figure out (1) a way to incorporate fruit liquid (b/c fruit juice or puree is not as concentrated as extracts, although they can be reduced to produce more flavor per amount of liquid), (2) how to substitute glucose for corn syrup and (3) what temperature to boil my sugars to.

Boiling sugar. This is where it gets fascinating… and tricky. If you put a layer of sugar on the bottom of a pot and put it over heat, it’ll melt and caramelize quite rapidly; sugar reaches the caramel stage btw 320F-350F. It will color and when cooled, will be brittle and have a caramel flavor. This is the dry method of caramelization, which is something like gunning your car straight from 0-60mph in 6 seconds flat.

But, if you add water to the sugar and put it over heat, you can track the sugar gradually going through all of its stages, such as thread, soft ball, hard crack, etc.

What I find so interesting is that the temperature of the sugar will not increase until its water content decreases. So, when you use this wet method, it’ll usually heat up to a little under 220F and hang out there for a while until enough water has boiled out of it for it increase, which it will do pretty rapidly. According to Jean-Pierre Wybauw’s book Fine Chocolates, Great Experiences, a sugar syrup at 219.2F has a water content of 35%. At 221F, it has a water content of 30.6%. In the difference of only 1.8F, it has 4.4% less water! When it has reached the thread stage (which begins at 230F), it has 19.1% water. And so on, it progresses. Wybauw’s chart goes to 266F (the end of Hard Ball), at which point the syrup solution has only 4.9% water. When it finally caramelizes, the water is boiled off… so it can wind up just like the dry method.

So, knowing the % of water supports what the names of the sugar stages and temperatures intuitively tell you — as they get higher, they have less water to lend flexibility… hence, they get harder and more brittle. You’ll notice that the syrup thickens as the temperature increases by the way the bubbles act, but it has to cool for you to see how hard it will be (you can either pour it out and wait or drop a little in cold water for a quick test).

But… if only it were that simple… if only mastering this concept would allow you to master nougat-making. I consider there to be at least four factors that further complicate all this in regards to nougat:

  • the type of sugar that you use - do sugars other than granulated sugar (such as corn syrup and glucose) have the same properties at the same temperatures? Almost all candy recipes contain liquid sugars in addition to granulated. A corollary issue — what proportion of each sugar should you use? Most nougat recipes are a combination of glucose/corn syrup/honey and sugar. And nougat recipes call for boiling to be anywhere from 252-310F.
  • what you add to the sugar solution - How much egg whites to use? How much liquid can you use without it ending up all oozy, no matter what you boiled the sugar syrup to (even caramelized sugar–with its very small water %–can be liquefied again by adding enough water/cream/liquid)? How will acidic ingredients affect it?
  • the effects of room temperature and humidity - or as I’ll call it, the Cosmos Laughing at You Factor, b/c it seems like even temp/humidity controlled areas can be affected by the rain outside.
  • the effects of time on texture - sugar can have a way of sort of re-crystallizing over time, which can be great if you can predict it for a desired texture. Whether or not it is enrobed (that is, sealed off from air) is also a factor in this. Some nougats are supposed to be left out overnight, and some are supposed to be enrobed right away. As I read in Emperors of Chocolate, the Milky Way nougat takes two weeks to reach its preferred texture — under what conditions is it left for two weeks, and why does their formula take two weeks for the texture to come about?

So, I looked around in books and online and formulated a sugar syrup that was about 1 parts granulated sugar to 2 parts glucose, and enough water to moisten it; I wanted it to be chewy and moist, without much recrystallization. I boiled it to 252F, and was able to make a nougat out of it that was nice — soft and melting… perhaps a little bit too much so.

For subsequent trials, I decided to boil it higher, to 275.

And this is where it all fell apart.

The syrup wouldn’t incorporate into the beaten egg whites. It hardened into twigs of all size within the beaten egg whites and stuck to the whisk in a gelatinous, quickly-hardening clump. I thought it was a fluke — I’d never had this happen before with any of my “sugar-syrup-into-egg-whites” applications. Maybe the egg whites were too cold (which was unlikely, since they’d experienced all the friction/heat that it takes to whip them to medium peak)… Maybe I’d poured the syrup too much onto the whisk and it had cooled down… Maybe the syrup was too hot and should stop bubbling completely before being added to the egg whites… Maybe the syrup had cooled too much…

I tried again. The same thing happened. Sugar twigs in whipped egg whites. Some of the syrup had hardened onto the side of the bowl, before it had even reached the egg white.

So, I went back to the nougat recipes and looked again at their formulations. The one I’d primarily based it on had used a lot of corn syrup and a little bit of sugar. Other recipes, that used glucose to begin with, used almost equal amounts of glucose and granulated sugar.

And I believe that to be the difference. Glucose boils up differently than sucrose and corn syrup; it is after all, much thicker at room temp to begin with. The % of moisture in the Wybauw chart only applies to granulated sugar. In this case, I guess that the large amount of granulated sugar in relation to the glucose thins it out to a degree — a degree that the thinner corn syrup does not need. I had decreased the quantity of glucose from the original amount of corn syrup called for, in an attempt to compensate for the denser-seeming glucose, but that hadn’t been enough.

I now also wonder, though, how the percentage of liquid sugar in a sugar syrup affects the stage that the sugar is at at a given temperature. For instance, at 244 (”firm ball”), how will a sugar syrup with, say, 1 parts corn syrup to 2 parts granulated sugar differ from a sugar syrup with 2 parts corn syrup to 1 part granulated sugar?

So, anyway, for this nougat I was working on, I increased the ratio of sugar to glucose in my recipe until they were almost equal, fired up my stove and mixer once again… And it all incorporated beautifully.

And now I’ll be back at it again, to refine taste and texture…

Edit: McGee says that glucose caramelizes at 300F. I think that explains at least a bit.

20 Responses to “Nougat Science”

  1. Gerald Says:

    Nina - I’ve been enjoying reading about your candybar-making journey - and this post in particular. Thanks for the extremely detailed lesson on nougat, glucose, and syrups - I learned so much!

  2. Nina Says:

    Thanks…. So did I. :)

  3. McAuliflower Says:

    Fascinating!

    I’m assuming you’ve looked into eGullet as a resource? If not, I highly recommend the Pastry and Baking Board- confectioners lurk there.

    Regarding “fresh” flavors, sounds like essential oils will be your friend, esp where mint and citrus are involved.

    I’m looking forward to more reports… I like your sweet show-n-tell!

  4. Julia Says:

    I wondered about essential oils, too. Mint is tricky. I like the mint flavor that the Metromint Water people managed to get in their water. Maybe you’ll understand intuitively how they did it, but the orange and lemon mint waters are intriguing to a non-culinary scientist like me.

    I know this isn’t the right thread, but I like the idea of crystalized rose petals for crunchy flavor. I also jumped immediately to pomegranate when you brought up lychee. I think both have potential.

  5. Nina Says:

    McAuliflower — Thanks :) Yeah, I’ve been checking out the eGullet boards… It’s really impressive what’s covered there, and how cookbook authors respond to posts about their recipes!

    And I’ve thought about essential oils, but I don’t know… I feel like if I’m going to fruits and herbs, I may as well process them myself (using frozen purees is as far as I’ve gone from that idea). If I can’t get nougat to work with fresh ingredients, I’ll just use those flavors in another form; a ganache, for instance, can handle fresh fruit puree.

    To be honest, though, I really don’t know much about essential oils… I just know that I’ve had chocolates flavored with citrus/mint oils that tasted off to me… I’m not sure if essential oils are different…

    Julia - I like Metromint Water, too… and how they do it confounds me. :) I agree that mint is a tricky flavor. I’ve used fresh mint leaf in nougat and leaf croquant, and the taste is more herbal and less sharp. It’s good, but not the mint flavor expected in confections.

    And I like the idea of pomegranate with rose and lychee. Pomegranate seems like a more complex component, taste-wise, than raspberry… and less sweet, to boot.

  6. Julia Says:

    I feel like people overuse raspberry in candies. It’s good, but I get bored after a while. The thing about mint coming off as an herbal, earthy flavor is exactly what I mean. :) That’s good for tea and mint juleps and Indian Food, but one wants something more crisp in a chocolate.

  7. Nina Says:

    Julia - I think that my best bet is using a mint other than spearmint — like peppermint or black mint. Unfortunately, the grocery stores seem to only sell spearmint… and the farmers market that I went to this week only had spearmint, as well. I’m going to hold off on my mint bar until I can track down a better mint…

  8. Sweet Napa » Blog Archive » The Coffee Bar Says:

    [...] After all my experiments with nougat, I can make this one in my sleep now. I went through at least 10 different versions of the recipe (and made some versions several times). I adjusted the temperature it was boiled to, the ratio of sugar to glucose, the amount of chocolate in it, the type of chocolate in it, and more. It was wonderful to see how each factor affected the finished product — and how subsequent versions might have to be adjusted to compensate for certain results — but what’s funny is that my final version is almost identical to my first version. It turned out that decreasing the amount of egg white by just a 1/4 ounce in my first version fixed everything. How elegantly simple… at long last. [...]

  9. Sarah Says:

    Hi there, I have recently become obsessed with making nougat. I have downloaded a chapter from textbook which contains manufacturing instructions and recipes (20 or so) for different types of nougat. The one I tried in the weekend has two sugar parts. One contains the honey & glucose syrup, cook to 118C and whip in egg white (I used albumin powder), the other sugar part, white sugar & glucose syrup cooks up to 148C and is immediately added to still warm whipped egg/sugar part. This was white, glossy thick and beautiful but too chewy. Was yours less chewy? I’m trying to make a soft melt-in-the mouth type. The recipe also says to hold at 35C for 2 days! Let me know if you want the download I could email it to you..
    would love to know your recipe too.. thanks, sarah

  10. Nina Says:

    Hello Sarah, Yeah, nougat is a pretty delicate ecosystem. I think a lot of it has to do with moisture. The method you described sounds like a traditional version that turns out somewhat dense. If it’s a “hard” chewiness, it could probably use more moisture — you could try increasing the egg white, cooking the sugars to a lower temp, or subbing some granulated sugar for some of the glucose by weight. If it’s a “soft” chewiness, then you could do the opposite. You could also try adding a little confectioner’s sugar either at the end or mixed w/ the egg white at the beginning — just a little will shorten the texture a little and dry it a little, and make it less chewy.

    And I’ve read that the nougat in Milky Way is aged two weeks! At first, it’s almost like taffy, but it dries out more to its regular consistency. I’ve experimented a little when I had one batch turn out like hard taffy. I wrapped it up and checked it in about 3 weeks — and it had softened so that I could cut it and pinch pieces off, and it’s texture was airier.

  11. dee_lusions Says:

    This is a wonderful post. I enjoyed reading it very much. Thank you for sharing. A thought came to mind when you were discussing flavoring the nougat. A way to get intense flavoring without compromising the freshness of flavor, especially with fruit, is to use dehydrated fruit that has been ground into a fine powder that will basically melt into the liquid of your recipe. I’m not sure how you’d need to adjust the dry ingredients, but I do know that you’d get a wonderful burst of fresh flavor.

    I’ve done this with my pie fillings. Since I hate to cook away all the flavor of my filling, I use fresh fruit that I simmer gently until just barely softened in their juices with some sugar. Then I add agar agar and fruit powder. I get demands for my “secret” recipe. :)

    Mint or any kind of green flavoring would be more challenging since they don’t become instant even after dehydrating and grinding. I haven’t figured out a way other than making an infusion to incorporate things like mint and green tea. Have you found any other ways of incorporating these kinds of flavors?

  12. Nina Says:

    Thank you so much — for the praise and suggestions! :)

    I’ve played around a little bit with fruit powders in nougat, and they worked to an extent. To me, though, the flavor was a little off — it was more tart and woodsier than I like, and the (relatively bland) sweeteners used in nougat were never quite able to take the edge off; I even tried not to grind the seeds too much before straining them. The powder doesn’t dissolve completely, but it wasn’t not gritty at all so at least the texture was nice.

    Incidentally, in Happy in the Kitchen by Michel Richard uses raspberry powder in quite a few things…. and a lot of it! I made his meringue recipe, which has 1/2 cup egg whites to 3/4 cup raspberry powder, and wow, that was intense. It was also wild to see the powder almost instantly eat up all the moisture in the egg whites when they were folded in.

    I did try a mint nougat by slowly drying out fresh mint leaves in the microwave, grinding them up, and mixing them in. It actually worked nicely. The flavor remained bright, with a smooth texture, and it kept well.

    I haven’t been tried it, but I’ve been wondering if it would work to “infuse” sugar by putting dried mint or tea leaves into a canister of sugar for a long time, like for vanilla sugar.

    And I love your pie filling technique! I bet the flavors of the fresh and dehydrated fruit work together really well. I have to try that!

  13. dee_lusions Says:

    Woodsy? I’ve had that happen a couple of times when I’ve dehydrated my fruit too long. You might want to try playing with shorter drying times and lower settings. It affects the flavors of the fruits. Also, using things like lemon juice, sugar, salt, and other preservatives to keep colors and flavors can help or hinder the process.

    As for the tart flavor, it’s come down to me being a picky shopper. It’s taken years to learn how to identify those really yummy sweet strawberries that are going to go bad tomorrow as opposed to the ones that are truly going bad today ;p lol Of course, I still have to get out of season stuff, so I cheat and soak my cut berries in sugar water before dehydrating them.

    There are some books on dehydration for cooking, not just for food preservation that you might want to look up. I can’t think of the names of them right now… I’ll try to find them and post them here. I got them a long time ago, which started me on playing with fruit powders and many other ideas like veggie powders in soup stocks.

    Thanks for the compliment on the pie technique! I saw someone using it for a sauce recipe and I said, pie filling! Lol, I was making thanksgiving pies at the time.

  14. Nina Says:

    Oh, you know what, I used dehydrated fruit that I’d bought — I think the “simply” brand… and I tried blackberry and raspberry, both of which are probably most susceptible to a woodsy flavor from the seeds.

    I think that to get it right I would have to dehydrate them myself. I recently saw a Good Eats episode where he made made beef jerky on furnace filters blown by a fan…. Maybe I can rig up something like that. :) Or wait until his dehydrated fruit episode to run… :)

    And I’ll have to remember the sugar water trick, too… Amazing how sugar can bring out so much flavor. :)

  15. bill Says:

    i have been attempting to make torrone for about a week..

    2 questions i have are, mine always come out beige, not white….the sugar/honey mix tends to darken before hard crack stage..is this normal or should i stop heating before i get to 300 as my recipe states, and texture..im looking for a rock hard texture as my italian girlfirend desires, somebody suggestes mixing longer. Does oxygen and aeration play a role?
    Any advice on how to get whiter/harder candy would be appreciated

    Thanks
    Bill

  16. Nina Says:

    Hi Bill,
    I’ve never attempted torrone (or used honey in my nougat), so I”m not sure. I have seen recipes that call for boiling the sugar/honey to a relatively low temp (maybe 250F) and mixing half of that with the egg white, and then returning it to a boil to cook the rmg higher. That may lighten the color and hopefully there will be enough sugar boiled high enough for it to be hard.
    Good luck!

  17. Jay Says:

    So tell me, did you ever achieve the light and fluffy?
    I have been trying and failing to get fluffiness for a while. I even blew up a mixer trying to whip the mixture as it cooled (apparently cheap mixers shouldn’t be run for a long time with high temperature mixtures, who knew?)
    If leaving the product for a while makes it more fluffy, do we know why? My thoughts are on a change in moisture level, or time for incorporated air to expand.

  18. Allan Georgee Says:

    Hi everyone. I have really enjoyed reading this article and posts. I have been making nougat (more like the torrone Nina speaks of with Bill). I have been getting good results but find it a problem with the finished product wanting to ooze once cut. The only way to hold it together is to wrap it. Can anyone shed any light with their experiences? I live in a humid place in Australia and agree with the humidity issues.

    Looking forward to a response.

  19. Nina Says:

    Hello, It sounds like there is too much moisture if it’s oozing. I’d boil it to a higher temp. And if you’re in a humid environment, it’s best to wrap immediately once cool. Good luck!

  20. Kerri Says:

    First I’ll say that this post is brilliant. I love how much you’ve gotten into the chemistry of the sugar. I too am pretty fascinated by the progression of the wet sugar stages.

    Second, I want fluffy nougat! To be specific, I want divinity. I tried to make a divinity recipe and it ended up not only darker than one would have liked (making me think that I had cooked off too much of the water) but also too dense and oozy (making me think I had not cooked off enough of the water after all). I ended up salvaging it by forming it into bars, coating it in chocolate and quickly sticking it in the fridge to keep it’s shape. Once the chocolate had set the candies could be kept at room temperature and were pretty tasty, but not at all what I had aimed for. Any ideas on what went wrong?

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