Pretzels

FST 605 - Laboratory


Date Performed: January 22, 2002
Report Due: January 29, 2002

The purpose of this laboratory is to produce a food product and to become aware of the many instances where an understanding of chemistry is important in its manufacture. The product chosen is pretzels and the main variables we will examine are the color and texture of the pretzel's surface.


The class will divide into from five to seven groups and each group will produce twelve pretzels from dough made from the following recipe:

  • 1 bottle beer

    1 quart milk

    2 packages yeast

    4 tbs melted shortening

    6 lbs of flour

    2 tbs salt


    • The ingredients were mixed, the dough was proofed for 30 minutes and then pounded down. At this point each group will form twelve pretzels. Once formed, the pretzels will be dipped in one of the following solutions that have been heated to near boiling (except for the egg )

  • 1. 2% citric acid

    2. 2% NaOH

    3. 2% whey

    4. 2% Na2CO3

    5. Water

    6. Egg White


    • The pretzels will be placed in the heated oven ( 400° F) for 15 minutes or until done. Each group should obtain 2 pretzels from each other group and retain some of their pretzels. All pretzels should be compared and evaluated for:

  • General Appearance

    Color

    Texture

    Crust Formation

    Flavor


    • Rank all pretzels for each characteristic and determine which is the most acceptable product. The instructor will hand out data compiled by the entire class. Determine if the differences noted by the class are significant.


    Questions:


    1. What is the function of each of the following ingredients in the pretzel formulation:

  • Flour

    Beer

    Milk

    Salt

    Shortening


    • 2. How did each dip affect the surface of the pretzels? Postulate a mechanism for the observed effect.

    3. What caused the browning of the pretzel crust? How can variations due to dips be explained?

    4. Why was the yeast included in this product? What did the yeast produce? What did they consume? What components affected the retention of yeast by-products?

    5. If we had been making bread instead of pretzels, the milk would have been given a heat treatment. Why? Why wasn't this necessary with the pretzels?