Make Litmus Solution

Here is a familiar science lesson. I include it here because it correlates nicely with a previous lesson about using alkali to process corn. An alkali is a caustic or corrosive substance such as lye or powdered lime that is added to soil. As a caustic substance, it can help break down the coatings on corn. As lime, it helps lower or neutralize the acid in some soils. Thus, two important uses of alkalies are to break down difficult material, or to react with acids.

A gentle alkali is baking soda. A dangerous alkali is lye. The difference between the two is their position on the pH scale. The pH scale rates the acidity or alkalinity of a material. High pH can burn your skin and mucous membranes. Low pH can be used in baking. But how do you know the pH of a substance? Litmus paper, purchased at lab supply stores or some garden centers, will give you a reading. However, you can make your own litmus solution. This lesson shows you how.

Commercial litmus paper is soaked in a solution of water and lichen species. When you dip the paper into a liquid to be tested, the paper changes color. Match the color with the key that comes with the litmus paper and you’ll discover the pH value, ranging from 0 to 14. Low numbers are for acids, high numbers are alkali, 7 is neutral. The more extreme the number, the higher the acidity or alkalinity. Different litmus papers have different color values, but the numbers are standard.

Here is a simple pH scale:

Make Your Own Litmus Solution or Paper

Chop or tear leaves of purple cabbage. Put into a large pot and cover with water. (Note: the water source could make a difference. Tap water is generally neutral, which is what you want. Well water may start off being alkaline or acidic, which will affect the results of your homemade pH test.) Bring the water to a boil; then allow it to cool. Strain out the cabbage leaves and discard. Keep the water, which will be blue. This is your litmus solution.

Distribute the solution among several clear glasses. Keep one for comparison. This will be your “neutral”, unchanged solution and it represents #7 on the pH scale. Add a small amount of a substance you wish to test, into each of the other cups and stir. The color will change due to the acidity or alkalinity of each substance. Pink to deep red are acid; green to yellow are alkaline, also known as “basic.” Arrange the cups in order of color on each side of the neutral cup and you have your own litmus color scale. Be sure to label each cup.

From left: vinegar, orange juice, neutral, hardwood ash, calcium hydroxide, lye

Make litmus paper

Soak paper towel strips in the solution and allow them to dry. The color changes are not as dramatic as the litmus solution. You can drop liquids onto the paper, or dip the paper into liquids you want to test. If you want to test a powder, or soil, mix it with water first. Again, make sure your water is neutral.

Standardizing your tests

It is impossible to be completely accurate with the cabbage juice indicator, but you can approximate the standard pH test. Test the items on the standard test (graphic above) and note the color you get with the cabbage juice indicator. Either take a photo of your solution and then write the pH number on the photograph, or try to match the color with crayons/colored pencils. Keep these for future reference.

Don’t be limited by the items on the standard pH scale! Try all sorts of powders and liquids you find around your house. So much fun!

An experiment that didn’t turn out the way we anticipated (but we learned something important):

I taught this subject to a group of Kabul university chemistry students. The class was held in a hotel conference center. I instructed students to get a large pot of boiling water from the hotel kitchen. The hotel kitchen had just finished serving lunch to students and staff. Students were delighted to learn they could make their own litmus solution because litmus paper was difficult to come by, but purple cabbage was readily available from street vendors. The indicator solution was rapidly made, but the test colors kept coming out wrong. Everything was testing too alkaline. I decided the human dishwashers in the kitchen hadn’t rinsed the pot sufficiently after washing. It still had soap residue in it, which is alkaline. I was somewhat insulting of their care in rinsing pots and thought ruefully of the lunch we had just eaten, cooked in those same pots. Then it occurred to me that the well water serving the kitchen – and all of Kabul – might be alkaline itself. I checked this with local geologists who told me that the famously good Kabul water came from wells sunk deep into limestone layers. The limestone filters the water but adds alkali to it. Then I asked a physician whether this could be a cause of kidney stones that many residents had. “Yes,” he said. “Alkaline water can cause them.”

Two similar recipes; vastly different health effects

My Dad, Clavis Hinshaw, also known as CJ

My dad, known as CJ, grew up on a poor farm in central Indiana. His ancestors had lived in North Carolina and he still thought of himself as a southerner. He spoke often of the food he ate as a child, no doubt carried along with his ancestors when they migrated from North Carolina to Indiana in what is known as “the great migration.” A staple in his childhood diet was cornmeal mush, or simply mush. Here is a recipe for it, adapted from the website All Recipes:

Cornmeal Mush:

1 1/2 cups Cornmeal, 2 1/2 cups water, 1 teaspoon salt. Put all three ingredients in a heavy pan and bring to a boil, stirring constantly to prevent burning. When the water has been absorbed and the meal all incorporated, remove from heat. Serve as a sweet cereal with cream and maple syrup or as a savory dish.

Cornmeal Mush

Simple! Now compare that recipe to a recipe called sofki, traditionally developed by native Muscogee Indians in the southern United States and eaten perhaps for centuries before encountering Europeans. This recipe is adapted from the website https://mvskokecountry.online/2018/01/21/osafke-safke/

Sofki:

Place about three pounds flint corn in a bucket of water and let stand until kernels are soft. Drain the kernels and pound in a mortar while still wet. Remove any large or hard chunks. Put the ground grains into a kettle with three times the amount of water. (1 part grains to 3 parts water). Bring to a boil, watching carefully to avoid burning and stirring as necessary. When the mixture comes to a hard boil, add kvpe-cvfke, a drop at a time until the corn turns a slight yellow. Continue to boil, stirring often, until the liquid thickens and the corn is soft. Serve as a sweet cereal or as a savory dish.

Creek Indian Woman Sifting Sofki

Both recipes use ground corn and boiled water to create a mushy dish. Can you spot the difference in ingredients? One recipe led to a widespread disease in the American south, and the other prevented it. The difference is kvpe-cvfke, the Muscogee word for hardwood ash water. The disease it prevented was pellagra.

Pellagra victim

Hardwood ash water is created by dripping and straining well water through a bucket of hardwood ashes. That water then has an alkali in it, sometimes known as lye. Adding lye water to the corn as it cooked unlocked a vital nutrient: niacin. You encounter corn treated with lye if you buy hominy or hominy grits in the modern supermarket. Regular corn meal has not been treated this way. That’s not a problem if you eat a balanced diet, but poor white southerners often relied on corn as a staple in their diets and may not have supplemented it with enough fresh vegetables or meat. Lack of niacin in their diets resulted in pellagra, a disease that could cause the “four D’s”: diarrhea, dermatitis, dementia, and death.

It is interesting to note that Spanish explorers encountered corn being prepared this way by Native Americans. Spaniards introduced corn and corn meal to Europeans and European Americans but left out the important alkali process, also known as nixtamalization. Indiana, where my dad grew up, was rich in the tradition of eating cornmeal products. Corn was easy to grow in the farmlands created by cutting down vast forests. Grist mills were common on the creeks and rivers, and were a source of income for mill owners. It was easy and relatively inexpensive to take corn left over from feeding the hogs, to the mill for human consumption.

The discovery of the benefits of niacin and the prevention of pellagra makes for interesting reading. During the early decades of the twentieth century, the source of pellagra was at first thought to be germs. But the germ couldn’t be found and infection didn’t pass from one person to another. Still, the germ theory held on. A researcher Joseph Goldberger discovered that a balanced diet prevented and cured pellagra, but searched in vain for the reason. His suspicions of diet-caused pellagra were scoffed at. In one set of experiments, he fed dogs a diet rich in cornmeal such as the diet pellagra sufferers ate. The dogs weren’t interested in the food, so he added brewers yeast to stimulate their appetite. Dogs who ate cornmeal supplemented with brewers yeast did not get pellagra; other dogs did. It turns out that brewers yeast is rich in niacin. The missing element had been found.

How did scientists learn that adding lye to corn releases niacin? That calls for more research on my part.

You can try both recipes above to explore taste differences, or you can buy hominy grits from the supermarket and compare it to regular cornmeal grits (often known as polenta). For a more authentic Hoosier recipe, buy coarse ground cornmeal from an operating gristmill. Polenta is an excellent and tasty dish and I certainly prefer the name to cornmeal mush. Just don’t eat it exclusively.

Do It Yourself

I drove to a local Mexican grocery store over Christmas and perused their goods. Many Mexican chefs cook up tamales for the holiday and they do it from scratch. This calls for corn which has undergone the nixtmalization process. I bought a bag of corn and a container of “Cal” displayed alongside. Cal is calcium hydroxide, used in place of wood ashes or lye, to treat the corn. Online information says that Cal is less caustic than lye and gives the corn a better flavor. In a sign of the times, none of the store clerks knew how to use these ingredients. The butcher, a man who spoke only Spanish, was able to confirm that I had the right ingredients, via an interpreter who was mystified by the entire exchange. I heard a customer laughing about the difficulty of buying canned hominy at groceries that didn’t cater specifically to Mexicans. She was buying a can, so I asked her if she knew anything about using cal to create your own. She laughed, “Oh, you’re asking the wrong person! I didn’t even know you could do it yourself. Good luck!”

Naturally, I wondered how Cal compared with hardwood ash and lye as a caustic agent. I bought lye from a grocery store (near enough: drain opener containing sodium hydroxide), Cal from the Mexican grocery, and (hardwood) walnut ash from my fireplace. Then I used the cabbage juice indicator test to find out which was the most caustic. See my lesson on that subject! NOTE: lye/sodium hydroxide is EXTREMELY POISONOUS AND CAUSTIC TO SKIN.

I followed the recipe (below) for treating the corn from the website “My humble kitchen.” It confirmed what the grocery store butcher had told me. (https://www.myhumblekitchen.com/2009/12/nixtamal-preparing-corn-for-tortillas/)

Nixtamal

Ingredients:

  1. 2 quarts organic field corn
  2. 5 tbls Lime/Cal
  3. 4 quarts filtered water

Method:

  1. Rinse corn and remove any chaff.  Drain through a colander.
  2. In a non-reactive pot, mix water and lime over high heat until lime is dissolved.
  3. Add the corn and bring to a boil for 15 – 20 minutes.
  4. Remove pot from heat, cover, and let soak overnight.
  5. The next day, drain the corn through a colander and rinse.  If making hominy for posole, remove hulls at this time. The hulls are the little brown tips which can be rubbed or picked off.
  6. Place corn in a bowl and cover with water.  Allow to soak for 5 – 10 minutes moving the corn kernels with your fingers and then rinse again.  Repeat this process one more time.  This will ensure all traces of lime are washed away.
  7. Drain the corn through a colander and you’re done.  Homemade nixtamal!

Further resources:

Here is an excellent website about niacin, vitamin B3; it’s uses, etc.

https://www.healthline.com/nutrition/niacin-benefits#TOC_TITLE_HDR_5

And here is a recipe for substituting nixtamalized corn meal (pre-made, masa-harina) in a cornbread recipe:

https://www.thepioneerwoman.com/food-cooking/recipes/a99048/masa-harina-cornbread/