Aug. 10, 2005

Beef Jerky: Drying and Curing

One way of slowing down or stopping the growth of bacteria and food-destroying molds is to remove the moisture, since moisture is essential for the growth of most microorganisms. When American Indians hung strips of buffalo meat in the sun and wind, they didn't know they were creating a less desirable environment for bacteria. But they did know that dried meat (which came to be called "jerky" after the Spanish word for this food, charqui) remained edible a lot longer than fresh meat. Also, it weighed less, making it easier to carry when they traveled over the range.

You could compare the rate of spoilage by leaving a piece of fresh beef and a piece of commercially prepared beef jerky at room temperature to see which spoils first. However, the results are quite predictable and completely inedible. So we will concentrate on exploring various techniques for preserving fresh beef by removing water. Is it better to dry beef in air or in the oven? Does salt have an effect on the drying process? Experiment and find out!

CHECK WITH AN ADULT BEFORE YOU BEGIN THIS EXPERIMENT. Ask for an adult's help when using a sharp knife to cut meat or a heavy bottle or mallet to pound meat, skewering meat, or operating an oven.

Materials and Equipment

• 1-pound flank steak
• sharp knife
• cutting board
• heavy bottle or mallet
• salt (coarse or Kosher salt if possible)
• dietetic or postal scale
• pan with rack (a cake rack, or use the rack in the oven)
• string or long skewer
• paper and pencil

Procedure

Trim all fat from the steak. Cutting with the grain of the meat, make strips that are about 1 inch wide and 1/4 inch thick. Since the steak is probably more than 1/4 inch thick, you will have to split the steak through the thicker middle area by inserting the knife between the layers of muscle and cutting lengthwise. There should be eight to ten strips.

Lay the strips out on the cutting board and pound them with a heavy bottle (like a ketchup bottle) or a mallet until they are very thin. Divide the strips into two groups. Try to keep the two groups about equal to each other in the size and weight of strips. Sprinkle salt heavily on one group of strips. Pound the salt in. Turn the strips over and pound salt into the other side.

Divide the strips into four groups that will receive different treatment:

• Group 1: oven-dried, salted
• Group 2: oven dried, unsalted
• Group 3: air-dried, salted
• Group 4: air dried, unsalted

Weigh each strip carefully on a dietetic or postal scale. Record its weight. Note its position on the drying rack, if it is to be oven-dried, or its position on a line or skewer for air-drying.

You can hang strips for air-drying over a piece of string strung between two chairs. (We hung our strips by sticking a long shish kebab skewer through one end. The ends of the skewer were rested on the backs of two chairs, suspending the strips between them.) Hanging them near a radiator will shorten the drying time.

Place the pan with strips to be oven-dried in a very slow oven. It should be set at the lowest possible setting, about 150°F. Leave the oven door slightly ajar.

When dry, the jerky will be shriveled and dark. Our oven-dried beef jerky took 8 1/2 hours to dry. The air-dried strips took about 36 hours.

Observations

The strips will feel lighter in weight when dry. Weigh each strip and calculate the percentage of weight loss using the following formula:

Percentage of weight loss = (fresh weight – dried weight)/(fresh weight) x 100

After the oven-dried jerky cools, try breaking it. Try breaking an air-dried strip. Which treatment gives the crispest jerky? Which gives the toughest? Does salt have an effect on the drying process? Eating the jerky will give you some of the answers.

For Further Study

Pounding salt (or other spices) into meat is called dry-curing. Salt draws moisture out of the meat; the water in the muscle cells flows out to the saltier area outside the cells.

Try making beef jerky with a wet-curing or brine treatment. Soak the meat strips overnight in a mixture of 1/2 cup coarse salt in 2 cups water. Pat dry with a paper towel and use the air-drying or oven-drying procedure. Be sure to air- or oven-dry untreated strips simultaneously so you can compare results. Which is more effective, dry-curing or brine-curing, for the drying process?

Reprinted with permission from More Science Experiments You Can Eat by Vicki Cobb. Text © 1979 by Vicki Cobb (www.vickicobb.com). Published by J.B. Lippincott.

Talk Back: Do you have any comments about this activity? Send them to us using the form below.

I have my parent's permission to submit this.
First name:		Age:
City:		State:	AK AL AR AZ CA CO CT DC DE FL GA HI IA ID IL IN KS KY LA MA MD ME MI MN MO MS MT NC ND NE NH NJ NM NV NY OH OK OR PA RI SC SD TN TX UT VA VT WA WI WV WY
E-mail:
Comment: