Target Grade Level / Age Range:

5th grade

Estimated Time:

3, 45-minute class periods

Purpose:

Students work together to solve a problem by engineering a fridge/freezer grape jelly recipe. Through this lesson students learn about the physical properties of grapes and how to write a recipe using fractions. Using the engineering process, students gather data and refine their grape jelly.

Materials:

  • 4-5 different varieties of Iowa grapes and juice such as Brianna, La Crescent, Frontenac Gris, Edelweiss, Marquette, Catawba, or others listed
    1. Note: these grapes cannot be purchased in stores and will need to be obtained directly from a vineyard. Please contact IALF (info@iowaagliteracy.org) for help finding a vineyard close to you. Alternatively, you could use 4-5 different grapes juices from your local grocery store.
  • Fridge
  • Sugar
  • Powder pectin
  • Jelly making kit
  • Ruler
  • String
  • Goggles
  • Aprons

Essential Files (maps, charts, pictures, or documents)

Vocabulary  

  • Jelly: a sweet, clear, semisolid spread or preserve made from fruit juice and sugar boiled to a thick consistency.
  • Vineyard: a plantation of grapevines producing grapes
  • Processing: perform a series of mechanical or chemical operations on (something) to change or preserve it.

Background – Agricultural Connections

Iowa grows a variety of juice grapes that are cold hardy. These grapes are used to make jams, jellies, and juice. In Iowa, most farmers cultivate juice grapes that are often used to produce juice, which is later fermented into wine. However, juice grapes can also be used to make jams, jellies, and juice.

Iowa grapes are unique and some of the varieties grown here are not grown anywhere else. With a winter that sees temperatures nearing the -20s, grape vines grown in Iowa must be cold-hardy. This adaptation allows for vines to over-winter without dying. There are a total of twelve different grapes grown in Iowa: Brianna, La Crescent, Frontenac Gris, La Crosse, Edelweiss, Vignoles, Catawba, Marquette, Marechal Foch, St. Croix, Frontenac, and Petite Pearl. Each grape also has a unique flavor. Flavor profiles of Iowa’s grapes range from light (citrus, fruity) to complex (pepper, plum, leather). Mixing different grape juices together can create new flavors and flavor profiles.

This lesson has students exploring the vast flavors of Iowa’s grapes and processing them into jelly. The first step to making grape jelly is processing the grapes into juice. To make the juice grapes are washed, stemmed, and then placed into a vat with water. They are then heated and crushed which denatures (breaks apart) proteins within the fruit. This process causes the fruit to release juice, flavors, and sugars. Leaving the grape skins on during the heating process increases the flavor that can be obtained in the juice. The left-over fiber (grape materials like the skin and seeds) is then placed in a sieve and pressed further to release even more juice (see this video about Welch’s juice making process). Once the juice is obtained it is boiled down to create a concentrate. This concentrate can be used as the base for a variety of grape products, like jelly!

Jelly is made when fruit juice is thickened using heat, fruit pectin, citric acid, and sugar. Pectin is a plant based threadlike carbohydrate that is often added to speed up the process of jelly making. It comes in two forms, liquid and powder. When pectin is added to the fruit juice it reacts with citric acid (all fruits have citric acid at varying levels). This reaction combined with sugar allows the pectin to create cross-thread bonds thickening the mixture into a jelly. Heating the mixture speeds up the thickening process and helps to dissolve the pectin. The type of fruit used in the jelly will alter the amount of sugar and pectin used.

When people process grapes into jelly in their home kitchen the same basic steps are followed, but on a smaller scale. First juice is made. Fresh grapes are washed, stemmed, and sorted to obtain the best grapes. The grapes are then placed in a non-corrosive pot and smashed using a potato smasher. Enough water is added to the grapes to prevent them from scorching or sticking to the bottom. This mixture is heated to break down the grapes. The juice is then strained from the grapes to be used to make jelly! (see Purdue’s website or this video for more information).

Even though sugar helps preserve jellies and jams, molds can grow on the surface of these products. This is why it’s important to store or process jelly appropriately. Jelly can be processed to be shelf stable or ready to use. In this lesson students make what is called freezer or fridge jelly. Fridge jelly has not gone through the canning process and is not shelf stable. This means that it is a product that is ready to use and should not be stored at room temperature. In contrast, shelf stable jelly has been processed through canning. When a jelly goes through the canning process it is heated to kill any bacteria that might be naturally occurring. This reduces the chances of mold developing on the jelly when stored at room temperature. For selling at farmers markets, jelly producers must follow the Home Food Processing Guides (Cottage Foods) of Iowa which includes processing jelly using the canning process.

Interest Approach – Engagement

  1. Discuss with students what grapes can be used for.
    1. Potential answers: juice, to eat, jelly, jam, pies, wine, raisins, etc.
  2. Present students with the engineering problem: Our local vineyard manager is wanting to make grape jelly using their grapes, but they don’t know which grape juices to mix to make their jelly. They are asking for your help to engineer a jelly recipe using the grapes they grow (list the grapes that are available to students). They are hoping that the jelly has at least 2 different grapes and a unique taste.
    1. Modification: if using store bought juice, alter wording to a local jelly producer.
  3. Discuss with students what they will need to do to help the vineyard manager. Make a list on the board.
    1. Potential answers: make jelly, taste the grapes, learn how to make jelly, etc.
      • If students do not offer the “taste grapes” add it to the list and let students know that this is where they'll be starting

Procedures

Explore & Explain

  1. Pass out the Grape Exploration sheet. Give students time to look over it and walk students through the sheet and the expectations of filling out the sheet.
  2. Provide students with the different grape options they have for their jelly making. Students then take time to fill in Grape Characteristics on their Grape Exploration sheet.
    • *Note: Grapes can have seeds in them. Make sure students are aware of this and spit the seed out.
  3. Randomly pair students into groups of 3 using sticks or counting them off. In their groups give students time to share their observations and what they found out about the different grape properties.
  4. Once each person in the group has shared their information, have students flip their sheets over.
  5. Remind students of the engineering challenge. Point back to the beginning items that students said they would need to know to complete the challenge. Remind them that one of the items was “how to make jelly”. Let students know that they will now explore how jelly is made by watching this video: Concord Grape Jelly Recipe | How to Can | Allrecipes.com - YouTube
  6. Bring the class together as a whole group. Ask the class what they learned about making jelly. While discussing with the class encourage students to fill out the Making Jelly portion of the Grape Exploration sheet. Make a list on the board, and let students know that they’ll follow the basic recipe that has sugar, grapes, and fruit pectin in it.
  7. Then let students know that they are going to create prototypes of our recipe. Discuss with students what a prototype is, and why we use prototypes. 
    • Possible answers: a test, replica of the end goal, mock-up, etc.
  8. Let the students know that there are two types of jelly, shelf stable and fridge jelly. Let students know that they will be creating fridge jelly as their prototype. Discuss with students the difference between the two types of jelly and why fridge jelly would be best for their prototype. 
    • Possible answer: Time, to make shelf stable jelly it will take a lot more time, and time is money. Thus, making fridge jelly
  9. Ask students how they might create a prototype of the jelly recipe.
    • Possible Answers: 
      •  Let students know that we are going to modify our recipe, so they don’t waste ingredients. Have them fill in the My Groups Jelly section with the modified recipe:
        • 1 ¼ cup + 2 Tbs of sugar
        • 1 Tbs of pectin.
        • Using this recipe each group will make ~2, 8oz jars of jelly (this is the size of a common jelly jar).
  1. Then let students know that in their group they will need to decide which grapes they will want to mix to make jelly and why. Instruct students to follow the My Groups Jelly section on their handout. Students work together to engineer their grape jelly recipe.
    • *Note: in the recipe the only thing that changes are the types of juice added. All other variables will stay the same.
  2. With the help of the teacher, groups make their jelly using the grape juice that is prepared. This will take multiple days and could be done with one group making their jelly each day. When making jelly students should wear goggles and aprons for protection. Use the Grape Jelly Directions Pictograph to assist in the jelly making process.
    • Optional Modification: rather than having students make their jelly and having them complete the Elaborate portion of the lesson, you could have students move onto the Evaluate portion where they share their idea with the vineyard manager and each other.

Elaborate

  1. Allow students to perform taste tests of their jelly and other groups jelly using the Grape Jelly Review sheet. Using this data, groups graph their results and propose changes to their recipe using the Grape Jelly Next Steps sheet.
    1. Potential recipe alterations: juice used (to change flavor), amount of each juice used (to change flavor), amount of pectin (more or less to change thickness), amount of sugar (more or less to change thickness), boiling times, etc.
      • *Note: to follow the complete engineering process, you’d repeat students making their jelly, however, having them consider what they would change is also sufficient.

Evaluate

  1. Students write a letter explaining their recipe and pitching their recipe to the vineyard manager. Their letter should introduce the topic and convey information about their recipe including visual, tactual, or multimedia information as appropriate. It should also provide facts, details, or other information related to the topic such as the process students to determine which grapes to use, safe food handling, or how processing their grapes affected the product.

 

Did you know? (Ag facts)

  • Iowa used to be ranked 11th in the USA for grape production.
  • In 2021, Iowa sold 1.1% of its juice outside the state!
  • Multiple grape juices can be mixed to create new complex flavors.

Extension Activities

  1. Have students explore the history of grapes in Iowa.
  2. Students can learn other ways that grapes are preserved through this lesson.
  3. When making the jelly, students can weigh their ingredients. Students then record the weights of their ingredients before and after making the jelly. Then have students create a graph comparing the weight of the ingredients before and after. Are the weights the same? Why or why not?
  4. Connect with art and nutrition by having students design their own label using current legislative laws.

Suggested Companion Resources

Sources/Credits

Author(s)

               Cathryn Carney

Organization Affiliation

  • Iowa Agriculture Literacy Foundation

Agriculture Literacy Outcomes

  • T3.3-5.c. Distinguish between processed and unprocessed food.
  • T3.3-5.e. Explain the practices of safe food handling, preparation, and storage.

Iowa Core Standards

  • Science
    1. 5-PS1-2. Measure and graph quantities to provide evidence that regardless of the type of change that occurs when heating, cooling, or mixing substances, the total weight of matter is conserved. (*Only if Extension 3 is completed)
    2. 5-PS1-3. Make observations and measurements to identify materials based on their properties. 
    3. 3-5-ETS1-1. Define a simple design problem reflecting a need or a want that includes specified criteria for success and constraints on materials, time, or cost. 
    4. 3-5-ETS1-3. Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved.
  • Math
    1. (5.NF.A.2) Solve word problems involving addition and subtraction of fractions referring to the same whole, including cases of unlike denominators, e.g., by using visual fraction models or equations to represent the problem. Use benchmark fractions and number sense of fractions to estimate mentally and assess the reasonableness of answers. For example, recognize an incorrect result 2/5 + 1/2 = 3/7, by observing that 3/7 < 1/2. (DOK 1,2,3)
    2. (5.G.A.2) Represent real world and mathematical problems by graphing points in the first quadrant of the coordinate plane, and interpret coordinate values of points in the context of the situation. (DOK 1,2)
  • Literacy
    1. Writing 
      • Types and Purpose
        • (E.E.W.5.2) Write to share information supported by details.
          1. a. Introduce a topic and write to convey information about it including visual, tactual, or multimedia information as appropriate.
          2. b. Provide facts, details, or other information related to the topic.
      • Production and Distribution
        • (EE.W.5.4) Produce writing that is appropriate for an explicitly stated task or purpose.