Why do so many recipes call for powdered sugar instead of regular sugar?
This is a question I've been wondering about for a while as a home baker and amateur food scientist. Why do recipes for whipped, fluffy desert components like whipped cream or buttercream icing always seem to call for powdered sugar? If I want to add sugar to a something, why would I also want to add the anti-caking agent (usually starch I think) for powdered sugar as well? Is that starch actually something beneficial for a whipped desert? Because as far as I can tell, the only time powdered sugar makes sense is when it's dusted on top of something or incorporated into a desert that is being mixed by hand and doesn't have the shear of a mixer to dissolve or emulsify the granulated sugar. And I've never had any issues just using regular granulated sugar and honestly prefer it to powdered sugar for icings, whipped cream and the like. If a recipe calls for powdered sugar, but it's being combined with a mixer or beaters I just use regular sugar and the results are great.
Anyone have any thoughts or experience as to what I'm overlooking? Or is it just a hold over from a time when electric mixers weren't common and you needed a finer sugar to incorporate the sugar by hand?
The recommended method for whipped cream is to keep everything - the bowl, the beater, the cream - very cold. This isn't a requirement, but it generally gives you a more consistent result when the ambient temperature and the like can fluctuate. The issue with doing this is that cold fluids don't tend to dissolve things as fast, which can lead to clumps of sugar in the end product. This is true to some extent in other creams, and you can essentially eliminate the risk by using powdered (or fine) sugar instead of granulated.
If this doesn't seem to be an issue for you, then I wouldn't stress about it. The majority of baking (ESPECIALLY home baking) is, in my opinion, an "if it works it works" kind of craft. If you have a recipe that you're well acquainted with, keeping and improving it will net you better results than trying to do things ""properly"".
As a fun experiment on the texture difference between powdered sugar and granulated, you can make small batches of whipped cream to compare. The granulated sugar can be fully dissolved, but it's a bit more challenging with cold cream. Powdered sugar also has an anti-caking agent which can help stabilize icings and creams (cookie icing especially).
Edit: u/Englerdy I forgot to mention super-fine sugar or caster sugar as the midway point between granulated and powdered sugar. It doesn't contain anti-caking agents, so it can replace granulated sugar 1:1. It's much more common in the UK. You can easily buy it online or try making it yourself: https://www.thespruceeats.com/how-to-make-castor-sugar-substitute-4137095
The sugar I've been using is just store brand and labeled something like "Table Sugar" (I decant it into an air tight container and don't have the original bag), however I wonder if it's actually caster sugar. After looking at some images online my sugar looks a lot more fine than granulated sugar. So maybe that's why it's been so easy to work with in icing and whipped cream. It's not actually granulated sugar but something finer! Thanks for pointing this out. 😂
I'll try making a powdered sugar whipped cream and a table sugar whipped cream to compare. That's a great idea and now I'm curious how they'll compare side by side.
What I'm still left wondering and haven't thought of a great way to test is how much of the dissolving of the sugar is done by the shearing coming from the beaters or mixer. As the sugar crystals experience liquid on two sides going different speeds or even different directions, how much does that contribute to sugar molecules detaching from the bigger crystal into the liquid? Even if it'd normally be hard to get them to homogenize by hand mixing, they experience much stronger forces when using something like a mixer.
I do like the sentiment about "if it works it works" which is usually my advice around castiron. When talking about it with people afraid to try cooking with them, my advice is that they'll see lots of conflicting advice online, but ultimately it comes down to having an extremely durable pan that can take a lot of abuse and if you mess it up somehow you can just start over no harm no foul.
It also feels like differences in elevation, local climate, and your own equipment creates enough variability that practice is the biggest piece to figure out what works in your kitchen.
That sounds like a very annoying chemical engineering question lol... I don't imagine the shearing between the moving and still liquid is very important for dissolving. The force with which you're moving the sugar crystals and temperature likely matters much more. My basis for this is that when you're making coffee or tea and trying to dissolve the sugar clumped at the bottom of your mug, simply swirling the water doesn't do much. Working the sugar out of the bottom of the mug matters a lot more.
I can definitely see it going either way. I'd counter that it's a very interesting chemical engineering question! I think the biggest difference with movement is that as the surface of the crystal is dissolving, the movement is going to constantly sweep the high concentration dissolved interface away from the crystal's surface and expose it to more low concentration bulk material. So how much of the dissolving phenomina when mixing is the shear force helping break the surface bonds vs how much is the effect of keeping the crystal surface exposed to a low concentration medium (where diffusion will happen the fastest) is hard to say. Probably strongly material dependant. Then, as you touch on, when you add temperature variability there's a whole other dimension to consider.
But the more I've thought about it, the more I suspect that dissolving using mixing is probably a combination of sheer and concentration at work. I've got some chemical engineers not to far away in my professional circle and will have to reach out to one and get their thoughts. I still can't shake this problem. It's a fun one so thanks for indulging me. 😂
You can also pulse granulated sugar to a finer powder in a food processor if you plan to use it immediately. Otherwise, the fine sugar powder tends to adsorb moisture from the air (especially on humid days) and clumps very quickly.
That's a great idea! I have a small bullet blender that would probably do a good job at this.
As I just mentioned in my comment to @Minori, I think the store brand sugar I've been getting is already closer to a caster sugar than a granulated sugar anyway. So I think that's been contributing to it's ease of use for me in making more delicate deserts.
Specifically in whipped cream, the starch in many powdered sugars acts as a stabilizer, so the whipped cream stays whipped for longer. However you can buy organic powdered sugar without added starch (as I do.) In that case, the powdered part simply improves the ability for the sugar to dissolve and improves the lightness. Depending on your needs, you may want to add some cornstarch if your powdered sugar does not have any.
It sounds like I'd have to do three tests then. One with granulated sugar, one with regular powder sugar, and one with non-starched powdered sugar and see how they compare for taste and texture! I'll have to check around and try finding powdered sugar without starch. And if I can't find it I'll do my best to blend some in my bullet blender and make some.
Where do you buy powdered sugar without any anti-caking agents? All the organic powdered sugar I'm familiar with uses tapioca instead.
Powdered sugar has a greater surface area because of its smaller crystal size. This makes powdered sugar quicker and easier to dissolve than regular granulated sugar.
Due to these properties, powdered sugar absorbs more moisture, which is why usually an anti-caking agent is added to prevent clumping.