Our Observations on the four experiment
- This experiment took much longer than expected.
- With 3 of us each working with different types of flour, it was harder to compare. A 7-year-old was less patient than her 11-year-old brother with running water over the flour ball.
- Max couldn’t wait to get the flour off his hands and did not want to taste anything.
- Lexi, 7-years-old, loved the experiment. She enjoyed touching and comparing the dry flour, squeezing the wet flour, and she even tasted one of the gluten balls. She said it tasted awful!
- They both enjoyed reading about gluten and seeing how the flour changed.
- In our experiment, the whole wheat bread flour was slightly smaller than the unbleached all purpose flour. I expected the bread flour to have more gluten.
- We enjoyed doing the experiment.
The flour gluten experiment
The full experiment can be downloaded below. Make your own predictions and observations.
Science Experiment with Flour
Why is gluten so important? Without it, there would be nothing to hold the gas that makes bread rise.
Think of gluten as the rubber of a balloon: The stronger it is, the more gas it can hold.
But stronger isn’t always better. For many baked goods, like pastries and pie crusts, it’s important to avoid gluten development.
That’s why different flours contain different amounts of protein, depending on how they are meant to be used. A high-protein flour will make a dough with strong gluten, good for hearty yeast breads. Pastry chefs, on the other hand, prefer low-protein flours that yield delicate, tender doughs.
The following activity is a great way to get a feel for gluten, and to find out why using different flours can lead to such different results.
What you will need:
- Two or three different flours made from wheat such as whole wheat bread flour, gluten flour, cake flour, pastry flour or all-purpose flour (You will need one cup, plus a couple pinches extra, of each flour type.)
- whole wheat flour bread flour, all-purpose flour, other flour
- water (1/2 to 3/4 cup for each flour you’ll be using)
- bowls (one for each flour you’ll be using)
Which flour do you think will have more gluten?
Which flour do you expect will be softer?
Do you think the cooked gluten will taste like bread?
- Into separate bowls, measure out 1 cup of each of your flours. If your bowls look different, remember which one contains which type of flour. If not, label them. How do the different flours feel in your hands?
- Slowly add about 1/2 to 3/4 cup water to the flour in each bowl stirring until the mixture holds together. Sprinkle the same flour on hands and work surface. Knead each mixture until it forms a soft, rubbery ball of dough. Let the dough balls sit for about 10 minutes.
3. In the sink, run cold water over one of the dough balls. Be careful not to let the dough disintegrate; try cupping your hands around the ball and squeezing gently to remove the starch. With low-gluten cake or pastry flours, you may want to put the dough in cheesecloth in order to hold it together.
4. You’ll notice the water turning milky as it washes away the starch in the dough. Keep pouring out the cloudy water that collects in the bottom of the bowl. Slowly, your dough ball will become a gummy, slimy network of gluten strands.
5. When the water no longer becomes milky, you know there’s no more starch in the dough, leaving nearly pure gluten. Notice how much smaller your ball has become—and how much more stretchy!
6. Repeat steps 3 to 5 for each of your flour types. How does the texture of each one differ as you wash away the starch? Does it take the same amount of time for each one? Are the gluten balls all the same size, or are some larger than others?
7. Now try baking your gluten balls in the oven for about 15–30 minutes at 450°F. When you take them out of the oven, you’ll notice they’ve puffed up and hardened, which is exactly what happens to the gluten in a loaf of bread as it bakes
When you knead dough, you help two proteins in wheat flour, gliadin and glutenin, form gluten. But flour also contains many other components—starch, lipids, sugars, and enzymes—that contribute to the consistency and nutritional value of bread. When you run water over dough in this activity, you wash away most of these other substances, isolating the gluten in the dough. In the oven, the steam produced as the gluten heats up expands the ball. Finally, the gluten hardens, and you have a finished gluten ball.
In baking, gluten is mainly used for the light texture and distinct taste it gives bread. But it’s also nutritious in its own right. It is, after all, almost pure protein. And because of its chewy texture, many people—especially vegetarians—find it to be an excellent addition to stir-fries and stews.
The gluten you extracted in the previous activity is technically edible.
Gluten experiment taken from:
Scrumptious Science: Great Gobs of Gluten
Goodness, Gracious, Great Balls of Gluten