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Notes for teachers

I began making yogurt at school after I saw so much leftover milk from breakfast being thrown away. I bought a used Instant Pot at a Savers thrift store that I keep in my classroom. It doesn’t take long to accumulate the 16 cartons that make a gallon of milk to start the process of making fresh homemade yogurt. The only other ingredient required is about a cup of plain yogurt as starter (easy to retain some starter with each new batch).

This lesson can include the yogurt making process, or it can simply use the yogurt you have already prepared, or purchased.

What I do to prepare Instant Pot yogurt:

Especially if students are helping, ensure hygiene of hands, utensils, and surfaces.
Fill Instant Pot liner to top line with a gallon of milk.
Using the yogurt settings, bring to a near boil 180°F (82°C).
Cool back down to 104°F to 115°F (40°C to 46°C). Time will get it there, but to accelerate the process I remove & cover the pot with plastic wrap & put in an ice water bath.
Return pot & add the yogurt starter & whisk.
Seal with lid and set for desired time (I use about 12 hours but you can extend your comparisons by sampling yogurts incubated for shorter & longer time periods.
Use a yogurt strainer to separate the yogurt from the whey for thicker Greek-style yogurt.
Plain yogurt can be modified with vanilla extract and sweetener.

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Notes for teachers (Cont’d)

Download a copy of my recording sheet & edit for your needs:

https://docs.google.com/document/d/18pUjpYBadbWmymq-lWot5yhtp1ok6klKiW6HjCyOFmY/edit?usp=sharing

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List of Materials

Materials:

Labeled containers of yogurt samples for each table group:

A (plain yogurt)
B (yogurt made with chocolate milk)
C (plain yogurt with vanilla & sugar added)
D (plain yogurt with vanilla, sugar, and food coloring added)
Enough taste spoons (popsicle sticks work) so students don’t double dip!
paper towels
Observation/recording page

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Science & Engineering Practices

Analyze and Interpret Data
Engage in Argument from Evidence
Obtain, Evaluate, and Communicate Information

Construct Viable Arguments and Critique the Reasoning of others

Look for and Express Regularity in Repeated Reasoning

Standards for

Mathematical Practices

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Core Idea for Knowing Science:

L1 Organisms are organized on a cellular basis and have a finite life span.

6.RP.A.3.d

Use ratio reasoning to convert measurement units; manipulate and transform units appropriately when multiplying or dividing quantities.

6th grade Math Standard

Core Idea for Using Science:

U1 Scientists explain phenomena using evidence obtained from observations and or scientific investigations. Evidence may lead to developing models and or theories to make sense of phenomena. As new evidence is discovered, models and theories can be revised.

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Objectives:

Today we are using our senses to investigate a variety of yogurt samples so that we can record, organize, and analyze our observations.
We can use our observations to write a claim, support it with evidence and reasoning.

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Agenda

1-3 sessions of 45 minutes:

If only 1: Intro, Taste Test 2 or more samples, Documentation.

I used multiple sessions as I deliberately used these lessons to introduce some of the science practices as well as my own classroom routines and procedures during the opening weeks of school

1: Intro & taste 2 samples, record
2: Taste 2 more & make comparisons with Venn diagrams
3. Evaluate predictions with Claim, Evidence, and Reasoning

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Intro/Driving Question/Opening

Curious people have been making observations about the world since long before any sophisticated tools were available. What senses can you use to learn about the things around you?

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Intro/Driving Question/Opening (Cont’d)

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Hands-on Activity Instructions

As a whole group I introduce the tasks. I ask students to make predictions and to record all of their observations as data to return to later. We discuss the types of observations they will make in their teams of 4, one sample at a time: A, B, C, D.
I then send them to lab tables preset with samples & sampling spoons, reminding them to use the recording sheet to record their observations.

What do you see? Color?
What do you smell? Anything? Odorless? Tangy?
What does it feel like between your fingers? Thick? Thin? Runny?
What does it feel like in your mouth? Cold? Creamy? Slippery?
What does it taste like? Sour? Sweet? Tangy? like something you’ve tasted before?

After recording observations, they clean up the tasting area, and return to organize their observations into Venn diagrams.

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Resource for customizing Venn Diagrams

https://www.mural.co/?qgad=767356555650&qgterm=mural&utm_medium=paid-search&utm_source=adwords&utm_campaign=22852993590&utm_term=mural&utm_adgroup=189079684011&utm_mt=e&gad_source=1&gad_campaignid=22852993590&gbraid=0AAAAACccUG2yIfikH3nMVf5ouyMg4twI7&gclid=EAIaIQobChMIhMeD6ea1jwMVxhWtBh0lkjeyEAAYASAAEgIwWvD_BwE

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Assessment

Download a copy of my rubric & edit for your purposes:

https://docs.google.com/document/d/1sZelYb-stJUX7zsgCJ8xoPgHYaKwm_hRoHSSfTcKBGM/edit?usp=sharing

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Differentiation

Remediation

Extension/Enrichment

This activity has a wide appeal and the recording can easily be simplified; Observations may be recorded in a T-chart between 2 samples or prompted with a checklist form:

Color:

white
brown
blue

Taste:

Sour
Sweet
Tangy

For lactose intolerant students, yogurt can be made with almond milk or other dairy-free options.

Life Science:

While using this exercise to introduce my new 6th graders to my classroom and the science/math practices they will be using in middle school, it is also ideal for 7th graders learning about living vs. non-living things. Posing the question: Is Yogurt living? is a great phenomenon to use to evaluate the characteristics of living organisms. Students may be able to use yogurt samples to observe bacteria under a microscope. https://www.youtube.com/watch?v=PdDAgwTB4-0

More Collaboration:

The Mural website I used to create my Venn diagram templates has the capacity for collaboration that I have not yet used in my classroom, but intend to try. Students might collaborate on their data presentation with Venn diagrams and other visual representations.

Kitchen Math & Science:

How much yogurt is yielded from a gallon of milk? What percentage is yogurt and liquid whey?