Observations
  • Home
  • Observations
  • Trendcasting
  • Odds 'n Ends
  • Science/Technology/Experiments
  • Mental Health

Time to make yogurt!

5/22/2011

0 Comments

 
Picture
We don't usually associate cooking with chemistry but cooking really is a chemical process. Instead of a recipe it is a formula. When we subject food to heat, there are several changes in both physical and chemical composition. In the manufacture of yogurt we see a special kind of change due to fermentation. Better known for making alcohol, fermentation has some very interesting properties. We will be breaking down the protein in milk to make a tangy, and probiotic rich food. Any kind of milk can be used, but regular milk from cows will be used here. It can be whole, 2%, or skim milk. The fat content will remain the same as what we start with. We will be making a small batch size to illustrate the easy, and fun way to make yogurt at home. Scaling up is easy as well, and the process is exactly the same.

Parts and pieces...
  • 1 Cup milk, whole, 2%, or skim
  • 1/2 Tablespoon plain starter yogurt. Any commercial kind with active cultures
  • 1/8 Teaspoon sugar
  • Glass container, microwave safe if using microwave oven
  • Fahrenheit or Celsius thermometer-Helpful but not absolutely necessary 
Picture
I am showing how to make yogurt on the stove top but the microwave works as well. Just use a microwave safe container. The first step is to scald the milk. A temperature of 180 F ( 80 C) will be fine. We don't want to boil the milk, just scald until a skin forms on top. This will kill any bad or competing bacteria. Let the milk cool to about 110 F (43 C). If you can put your finger in the milk for a few seconds without being too hot it is close enough. Add the starter yogurt and the sugar and stir well. Bacteria thrives on sugar and it really promotes good conversion. Now, set aside for 4 to 7 hours. It is important to keep the container warm for as long as possible. In the stove top version I just cover and set aside. The temperature then slowly goes down which is fine. So, if you use a microwave, transfer to a 100 F water bath, on in a saucepan with a cover as I have done. I will explain the time factor in the next step.

Picture
In step two we will watch for the milk/starter to thicken. This is the time to place it in the refrigerator to completely solidify. In the fermentation process, the milk conversion forms lactic acid when it become yogurt. The longer it ferments, the more lactic acid and the more tangy or sharp it becomes. So, if you prefer milder and slightly more liquid yogurt, go with the 4 hours. For real zest, increase to the seven hours.

Picture
After refrigeration it is yogurt! There are many people who simply don't like the taste of plain yogurt and add honey or other sweetener. I like to add fresh fruit as well. This yogurt will last for 1 to 2 weeks in the refrigerator. This new yogurt can also serve as the starter for the next batch. Simply take out the amount needed and freeze. Thaw before use.
There is a great amount of information available on the Web, so check it out and have some fun!



0 Comments



Leave a Reply.

    Author

    The author has an eclectic background in chemistry, electronics, writing, mental health, and community action...Ken

    Archives

    June 2021
    March 2020
    September 2019
    August 2018
    August 2017
    March 2017
    December 2016
    November 2016
    October 2016
    August 2016
    April 2016
    December 2015
    September 2015
    May 2015
    March 2015
    February 2015
    December 2014
    November 2014
    October 2014
    September 2014
    August 2014
    July 2014
    June 2014
    May 2014
    April 2014
    March 2014
    February 2014
    December 2013
    November 2013
    October 2013
    August 2013
    July 2013
    June 2013
    May 2013
    April 2013
    March 2013
    February 2013
    January 2013
    December 2012
    November 2012
    October 2012
    September 2012
    August 2012
    July 2012
    June 2012
    May 2012
    April 2012
    March 2012
    February 2012
    January 2012
    December 2011
    November 2011
    October 2011
    September 2011
    August 2011
    July 2011
    June 2011
    May 2011

    RSS Feed

    Categories

    All
    Acid And Bases
    Amateur Scientist
    Anodizing Aluminum
    Anthocyanin Indicator
    Ant Orientation
    Artificial Intelligence
    Bar And Cr Code
    Cable Tie
    Carbon Dioxide Fun
    Catalase And H2o2
    Chemical Art
    Cold Cathode
    Color Hot Glue Sticks
    Common Chemicals
    Copper Plating
    Cyanotype/Blueprint
    Dot Com
    Electroluminescence
    Epoxy Art
    Experiments
    Hydrogels
    Infrared Photography Basics
    Magnetic Money
    Old Textbooks
    Photograms
    Science
    Static Electricity Detector
    Technology
    Yogurt