On Wednesday night, Aug. 27th, 2014 The Walder Center presented another great Kitchen Science program focusing on the properties of flour. Sarelle Weiner, pastry artist, engaged a group of in Modiin, Israel, in various activities relating to flour.
How to measure consistently so that the product can be relied upon to have the right texture and body. What are the different types of flour that are on the market and what are the uses for each type?
Then we learned about Gluten. Gluten is a complex protein formed when water is mixed with flour. The proteins Glutenin and Gliadin in the flour combine to form Glutenin when water or other liquids are introduced to the flour when making dough. Glutenin provides extensibility into the dough - the ability to stretch without breaking. A property of glutenin is to make the product chewy. Gliadin provides the elasticity into the dough - the property that causes the ends of the dough to snap back when rolling it out. Elasticity makes the dough keep it form as it breaks, as opposed to running over the pan.
When you are baking a cake- do you want it to be easy to cut with the edge of the fork, or difficult? More Gluten or less?
When you are baking cookies - do you want them to be crisp or chewy? More Gluten or less?
When baking muffins, do you need a batter that you can pour into a baking cup or a dough that you can roll out? More Gluten or less?
When baking bread, do you want a dough that's paper thin and can cover a table top withuot breaking, like a strudel dough? Or do we want it to rise as a thick tall loaf? More Gluten or less?
The evening developed as Sarelle challenged us to make strudel doughs and filling some with sweet and savory fillings. YUM YUM!
And we also learned a great bonus product that can be made with the strudel dough ends!
Buy the end of the session, all the participants felt that, with their new knowledge of flours, measuring techniques and gluten, they can now prepare winning holiday treats with confidence.
Science in cooking and baking equals spectacular products.
Once the word is out, the Walder Kitchen Science Focus on Flour with Sarelle has been requested in Chicago, and other locations.
Stay tuned!
Showing posts with label Biology. Show all posts
Showing posts with label Biology. Show all posts
Thursday, August 28, 2014
Sunday, May 11, 2014
Another Walder Kitchen Science Slam Dunk on Sunday May 11th
So what can you learn from cooking vegetable soup?
Just ask the kids from the Walder Kitchen Science Vegetable Soup exploration today, Sunday May 11th!
Biology, Chemistry and Physics!
We started off by viewing the streaming videos from the International Space Station and learning about the Earth's atmosphere. When not directly involved with learning about vegetables and cooking our soup, we tracked the ISS using the global tracker over both hemispheres and witnessed both Sunday's sunset and Monday morning's sunrise.
Ah! But what does atmosphere have to do with cooking vegetable soup? Plenty! Atmospheric pressure relates to boiling point which was demonstrated by shaking a soda bottle and slowly opening the cover. The Earth's atmosphere as seen by the ISS boils water at 100C at sea level. But what about on the top of Mount Everest? And what about on the shore of the Dead Sea? The same veggie soup is cooked more quickly at the Dead Sea than at sea level and more quickly at sea level than at the top of Mount Everest.
Enter, the pressure cooker! We compared a pressure cooker to a standard pot, described its features needed to cooked the veggie soup under pressure. So instead of allowing all that wonderful heat laden steam when boiling is achieved, the cooker's lid locks the evaporate in; causing the boiling to rise, causing the water to absorb more heat from the stove and forcing that heat into the food because it cannot escape!
And that is not all! Oh no, that is not all!
We also learned that heat cooking (heat transfer) takes place on the surface of the food. So the more surface the food has, the faster the food cooks. And how, pray tell, does one increase the surface area of veggies for soup? Chop, chop, chop!
We had a great time peeling and chopping our carrots and potatoes and onions and celery and mushrooms to increase their surface area to speed up the cooking process which was further sped up by increasing the atmospheric pressure in the pot!
When Rabbi Weiner announced that it was time to increase the veggies surface area, our 5th and 6th grade participants knew exactly what to do! Cut and chop away!
We also learned that the incense spices in the Beit Hamikdash (Ancient Jewish Temple in Jerusalem) were chopped and crushed to burn well and smell really good! All the while the Kohanim (Priests) chopped, they chanted "We chop it well, very well we chop!" (היטב הדק, הדק היטב).
But, of course, all this chopping took place after we examined our variety of vegetables and learned about leves, root systems, transpiration, respiration, and nutrient storage and photosynthesis.
And after stirring our biology together with the physics we added a dash of chemistry and talk about the chemicals released by onions when applying a mechanical force with a knife and cutting into its cells.
All is a day's soup.
We finished our session 2 hours later enjoying a healthy bowl of soup watching Monday morning's sunrise over the Sea of Japan from the International Space Station.
Everybody wants to know what's cooking next time in the Walder Kitchen of Science.
Tuesday, May 6, 2014
Kitchen Science and Vegetables this Sunday, May 11th!
The Walder Science Center at 3050 W. Touhy is conducting another great series of Kitchen Science Programs! Learn about vegetables and how to cook in a pressure cooker!
Science concepts:
Biology - study of plant parts by studying the various vegetables that will go into our vegetable soup.
The effects of increasing surface area - what do we accomplish when we finely chop up the vegetables and grind the spices?
Physics and Biology - what is released by the onion when you apply a mechanical cutting force to it that makes your eyes tear?
Physics - Why does cooking in a pressure cooker speed up cooking. How do atmospheric pressure and boiling point relate to each other?
Which leads us to... why is there no liquid water on the Moon or Mars?
Why was the Ketoret (incense in the Beit Hamikdash) ground up. Why was it doubly ground up before Yom Kippur?
Why do we grind up the maror (horseraddish) as close to the seder as we can?
Brings your heads and taste buds this Sunday and find out.
And take the tasty veggie soup that you cook yourself!
School age children, 5th through 8th grades: May 11, 2014
Girls, 10am until 12 noon.
Boys, 2 to 4pm
Tuesday, March 4, 2014
Recap of last Sunday's Walder Kitchen Science on Leavening March 2, 2014
itchen science for children on Sunday March 2nd was also excellent!
We focused on Leavenings.
We started off asking the participants if they remembered what we did a week ago.
Finally it was remembered (with a little of my prodding) that we learned about the makeup of the egg and the uses of yolks and whites.
We established that the structure of meringue cookies was constructed by whipping egg whites into a foam. This happens as we use mechanical force to attach air bubbles to the hydrophobic end of the egg white proteins.
We came to describe the process in which air bubbles are used in the formation of baked structures as "leavening".
Then, we discussed other methods of leavening, or generating air bubbles into a dough.
1. Using a living micro-organism called 'yeast' that eats and digests sugars in the flour and 'burps' out carbon dioxide bubbles. The yeast derives its energy from the food it eats and performs a chemical reaction releasing CO2 during digestion. Because it's a living organism, yeast does its best work at ambient or slightly warm temperatures. Put yeast in a hot oven and you kill it. Dead organisms don't eat or burp.
2. Using in inorganic chemical called sodium bi-carbonate, or baking soda. Soda is a base that will react with acids in the dough when water is introduced. The chemical reaction releases CO2 in the form of bubbles into the dough. Because baking soda is not alive, not only does one need to add heat to provide energy for the reaction, adding additional heat accelerates the reaction, sometimes too much. This leavening agent does its best work in a hot oven.
3. Some doughs do not have a great deal of acid in their mix to react well with baking soda. To remedy that, baking soda, the base, is mixed with weak acids like monocalcium phosphate or sodium aluminum sulfate to kick start the leavening reaction. The mixture is called 'baking powder'.
4. One can also leaven using steam, but we do not currently have the equipment that forces steam bubbles into a baking mix.
Using this information, we had a short discussion about the main difference between chametz and matza. Air bubbles, or leavening! The Torah tells us to avoid, on Pesach, baked goods pumped up with air bubbles, or leavened. On the other hand, we are supposed to eat a baked bread with as little possible air in it - matzah. We spent a few minutes on why that might be so.
The participants then designed an experiment using the following variables: Heat level (frigid, ambient, hot), and leavening used (none, yeast, soda, powder)
We formed 4 doughs. 1 with no leavening. 1 with yeast. 1 with baking soda. 1 with baking powder.
We split each dough into 3 pieces. 1 piece of each dough was placed in the refrigerator. Same for an oven warming at about 100F. Same for an oven at 350F.
Therefore, there were 4 pieces of dough representing each of the 4 leavening choices in either the fridge, the ambient oven and the hot oven.
While the participants observed the doughs through the windows of the toaster ovens, they worked on making 'matzahs' - pounding the dough flat, making holes with a fork and placing into a hot oven.
then we took some time to predict what we will expect to find. During this discussion, the participants volunteered that rising time and baking time were important variables, just like the leavening chosen and the temperature at which to leaven the dough.
After about a half hour we removed placed all the doughs in front of us on a table and compared and contrasted, size and shape. We then cut them open and described what we found. All the while attempting to explain the differences noted among the doughs.
Of course, we said Hamotzi on our matza and had that as a snack while we discussed our results!
We then reviewed and summarized what we learned, sang birkat hamazon together and adjourned.
They had a great time.
We focused on Leavenings.
We started off asking the participants if they remembered what we did a week ago.
Finally it was remembered (with a little of my prodding) that we learned about the makeup of the egg and the uses of yolks and whites.
We established that the structure of meringue cookies was constructed by whipping egg whites into a foam. This happens as we use mechanical force to attach air bubbles to the hydrophobic end of the egg white proteins.
We came to describe the process in which air bubbles are used in the formation of baked structures as "leavening".
Then, we discussed other methods of leavening, or generating air bubbles into a dough.
1. Using a living micro-organism called 'yeast' that eats and digests sugars in the flour and 'burps' out carbon dioxide bubbles. The yeast derives its energy from the food it eats and performs a chemical reaction releasing CO2 during digestion. Because it's a living organism, yeast does its best work at ambient or slightly warm temperatures. Put yeast in a hot oven and you kill it. Dead organisms don't eat or burp.
2. Using in inorganic chemical called sodium bi-carbonate, or baking soda. Soda is a base that will react with acids in the dough when water is introduced. The chemical reaction releases CO2 in the form of bubbles into the dough. Because baking soda is not alive, not only does one need to add heat to provide energy for the reaction, adding additional heat accelerates the reaction, sometimes too much. This leavening agent does its best work in a hot oven.
3. Some doughs do not have a great deal of acid in their mix to react well with baking soda. To remedy that, baking soda, the base, is mixed with weak acids like monocalcium phosphate or sodium aluminum sulfate to kick start the leavening reaction. The mixture is called 'baking powder'.
4. One can also leaven using steam, but we do not currently have the equipment that forces steam bubbles into a baking mix.
Using this information, we had a short discussion about the main difference between chametz and matza. Air bubbles, or leavening! The Torah tells us to avoid, on Pesach, baked goods pumped up with air bubbles, or leavened. On the other hand, we are supposed to eat a baked bread with as little possible air in it - matzah. We spent a few minutes on why that might be so.
The participants then designed an experiment using the following variables: Heat level (frigid, ambient, hot), and leavening used (none, yeast, soda, powder)
We formed 4 doughs. 1 with no leavening. 1 with yeast. 1 with baking soda. 1 with baking powder.
We split each dough into 3 pieces. 1 piece of each dough was placed in the refrigerator. Same for an oven warming at about 100F. Same for an oven at 350F.
Therefore, there were 4 pieces of dough representing each of the 4 leavening choices in either the fridge, the ambient oven and the hot oven.
While the participants observed the doughs through the windows of the toaster ovens, they worked on making 'matzahs' - pounding the dough flat, making holes with a fork and placing into a hot oven.
then we took some time to predict what we will expect to find. During this discussion, the participants volunteered that rising time and baking time were important variables, just like the leavening chosen and the temperature at which to leaven the dough.
After about a half hour we removed placed all the doughs in front of us on a table and compared and contrasted, size and shape. We then cut them open and described what we found. All the while attempting to explain the differences noted among the doughs.
Of course, we said Hamotzi on our matza and had that as a snack while we discussed our results!
We then reviewed and summarized what we learned, sang birkat hamazon together and adjourned.
They had a great time.
Thursday, February 20, 2014
Egg Yolks and Egg Whites
In our next Kitchen Science program, we will be focusing on the properties and uses of eggs. Egg yolks are used as an emulsifier binding fats like oil with water in bread and cake baking. Egg whites are used to build structure around air bubbles in meringues. Two interesting links are Food Additives athttp://www.understandingfoodadditives.org/pages/ch2p2-2.htmand Science of Eggs athttp://www.exploratorium.edu/cooking/eggs/eggscience.html
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