2 cups whipping cream
4 containers (jars with lids or ziploc bags) /
yogurt (live bacteria)
stop watch or watch with seconds hand
Take the cream out of the fridge. Put 1 cup on the
counter and put the second cup back in the fridge. Wait
about an hour until the cup on the counter is room temperature.
Label the four containers (warm, cold, warm + yogurt,
cold + yogurt).
Put 1 tsp of yogurt in each of the containers labeled
Add 1/2 cup of cream to the warm + yogurt container. Put
the lid on or seal the bag. Check the time. Start
Continue until it thickens (whip cream stage),
and then just a bit more. Suddenly it will separate into
butter and whey. Write down the end time. If you
can't get it to separate, try gently stirring it with a fork or
spoon. As you push it against the side, the butter should
clump together, separating from the whey.
Repeat step 4 for the warm container.
Take the cream out of the fridge and repeat step 4 for the
cold + yogurt container.
Repeat step 4 for the cold container.
Compare the different times.
Record the Data
Cold + Yogurt
Warm + Yogurt
What to do next?
Strain the butter. Save the whey to replace milk in
baking, or to drink. If you are having trouble separating
the whey, put the container in the fridge for about 15 minutes
and then try again.
Put the butter into very cold water to remove any remaining
milk. Stir or knead the butter in the cold water.
Replace the water if necessary. When the water is clear,
all the milk should be gone.
Taste the different types of butter.
Add salt to the butter and taste it again.
Weigh the cream to make sure each container has the same
amount. Compare the finished weights of the butter.
Think about why they might be different. Weigh each of the
whey containers to see if that answers your questions.
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