Home making salt dough with Thing 1 and Thing 2.
2 cups flour
1 cup salt
3/4 - 1 cup water
food coloring
Mix, play with, cut shapes, bake & paint.
Thing1 (a scientist) asks “What does the salt do?”
kdeus “I dunno. Let’s try it without the salt.”
Two batches later (one without salt) I still can’t tell any meaningful differences not other than water required (cuz less dry ingredients) and less volume (same).
What does the salt do in salt dough?
Being a microbiology lab guy, it’s obvious to me that it keeps it from being the perfect substrate for mold growth, but having a 3 year old, it also keeps kids form eating it.
Interesting about the mold growth. Thanks.
I was just about to laugh at you for saying that bit about kids not eating it, but in the interests of science, I tried a pinch of each. Holy crap that’s salty! I still think some kids (not my angels, of course) would eat it.
My post got appears to have gotten eaten (no pun indended).
I had asked if the salt might retain moisture better than the flour alone? If you hang on to them for a couple days, that’d be an easy way to find out.
Yup, always thought it was the bleurgh factor to prevent play-dough disappearance down tiny gullets.
The salt isn’t there to prevent kids from eating it. At any rate, that’s not its main and intended purpose. The patent for Play-Doh (#3,167,440, granted January 26, 1965 – which is pretty damned late; I was playing with this as a toddler well before that) states that sodium chloride, while best, might not be needed – you can sibstitute sodium hypochlorite, sodium chlorite, or potassium chloride, or even other salts. And the amount to be used is 1% to 25%. At the lower end of that range, you wouldn’t even notice it.
The salt seems to be essential for the dough. Doing a bit of a web search, we find this:
http://www.saltinstitute.org/53.html
So it’s there to make the dough strong, not wimpy like that “oobleck” mixture with cornstarch.
We’re talking about play-dough, right? Not bread dough. Since when does CO2 play a role in play-dough?
The quote is from a site about salt in food. In your typical bread, yeast or baking powder is put in to makw carbon dioxide to make the dough rise, or you get thick, chunky dough that’s really chewy. It’s not relevant to Salt Dough or Play-dough, as you note. My point in quoting the site was that the salt strengthens the gluten, making the dough tougher, which happens whether you have CO[sub]2[/sub] bubbles in it or not. And you want your Play-Dough or Salt Dough to have more tensile strength so your projects won’t fall apart.
Reading those sites, it turns out to be crucial when you add the salt for yeast breads. Too much salt can kill or inhibit the yeast. But I digress.
How do we know that the interaction between the salt and gluten doesn’t involve the baking process?
The CO[sub]2[/sub] in bread dough is a product of yeast, and so I don’t think it applies to Play-Doh, especially with the levels of salt we’re speaking of. There’s enough salt in the above-listed recipe to render the dough a bacterial wasteland. Yeast could simply not survive in that high-salt environment because of how salt tends to extract and retain moisture.
I strongly disagree with those sites which claim that salt strengthens the glutens in bread dough. If you compare this gluten-free bread dough and this bread dough and this recipe for pancake mix you will see the proportion of flour (per cup) and salt (per teaspoon) is about the same: 3.3:1, 4/1, 2:1. There is actually more salt in the instant pancake recipe and yet the pancakes are not stronger; rather the opposite. The salt is for seasoning, not strengthening. For strength you want protein — that is, gluten.
Gluten in bread dough is made by kneading the bread. The more you knead it, the more gluten. Some doughs and batters — pancakes especially — are intended to be mixed as little as possible to prevent gluten from forming, which would make the batter tough.
Since Play-Doh is made by design to be kneaded and played with, we should probably consider what happens if you over-knead ordinary bread dough. If you stick some bread dough into a stand mixer and let it knead with a bread hook for several hours, you will actually create strands of gluten so strong that you’d wring the water out of the dough. At that point the dough is useless for bread.
That is what I suspect the salt is for: to retain the moisture when the Play-Doh is, inevitably, kneaded to an inch of its life.
None of the sites (nor the books I’ve consulted, nor the patent) say exactkly what the salt is for. It seems to be considered necessary. Any number of sites tell you that the salt strengthens gluten. None of them say tyhat baking is necessary (although they are all from sites about baking bread or pizza, so they’d probably consider it unnecessary). Interestingly, even a recipe for gluten-free sasly dough includes salt:
http://www.kidswithfoodallergies.org/rice_playdough.php
But maybe that’s just to keep the kids from eating it.
Play-Doh doesn’t ned the salt to retain moisture – it’s got kerosene (!), alum, and borax for that.
Yeah, I would guess it’s to keep the thing from fermenting or growing mold.
Sites that tell you how to make Salt Dough still tell you to put it in the refrigerator, so it’s not clear it’s intended as a preservative (sites on bread claim that 1% salt won’t affect fermentation). The Play-Doh patent lets you get away with as little as 1%, and includes Borax explicitly to prevent mold. So Play-Doh seems to have the salt for some other reason besides preventing mold and keeping kids from eating it (although it can help do those things, too.)
I still don’t see how salt is essential for strength, if its concentration varies so wildly from one formula to the next.
When speaking of bread dough (or pizza dough), you put it in the refrigerator for a time to allow it to fully hydrate. I never kept my salt dough in the refrigerator and it didn’t spoil; it just dried out.
I’ve made lots of bread dough and pizza dough, but I admit I never made salt dough, so all I know is what I read. Al recipes for salt dough include salt. The Play-Doh recipe includes a wide range of some sort of salt (1-25%), which need not be sodium chloride. But they seem to feel the salt is necessary for something, despite the fact that they have other agents explicitly stated to be for preventing mold, hardening, or drying out. The patent doesn’t say exactly why the salt is there, nor does William Poundstone’s Biggest Secrets, nor do any of the websites I’ve found. But everyone agrees that salt strengthens gluten. If the salt’s not needed to strengthemn the mix, and it’s not needed for preventing mold, hardening, or drying, then why’s it there?
It’s not a preservative; it doesn’t need it.
I make salt playdough every week for my preschool class, and we never put it in the fridge. It lasts about a week (two classes a day, left out on the table for playing for about an hour or so in each class, doesn’t always get sealed in the baggie).
If you’re using it at home for just one or two kids, and you seal it up tightly when the kids aren’t playing with it, it will last a month or so.
JFTR, my recipe includes food coloring, 2 tablespoons of oil and 4 teaspoons of cream of tartar.