Fermentation has been used by mankind for thousands of years for raising bread, fermenting wine and brewing beer. The products of the fermentation of sugar by baker's yeast Saccharomyces cerevisiae (a fungus) are ethyl alcohol and carbon dioxide. Carbon dioxide causes bread to rise and gives effervescent drinks their bubbles. This action of yeast on sugar is used to 'carbonate' beverages, as in the addition of bubbles to champagne). [Note: In response to many questions I have received, here is a discussion of the small amount of ethyl alcohol which results in this root beer .]
We will set up a fermentation in a closed system and capture the generated
carbon dioxide to carbonate root beer. You may of course adjust the quantities
of sugar and/or extract to taste. (Zatarain's or Hire's have both been available
at my local Kroger's, but I prefer the taste of
Zatarain's, a product of New Orleans .)
[SUGAR SUBSTITUTES? Many people have emailed me asking about
substituting artificial sweeteners for the sugar in this recipe. The
short answer is no. Sugar is required for yeast to generate carbon dioxide
which carbonates the beverage. No sugar, no carbonation. You
might experiment with less sugar, and add a substitute to make up for the
lower sweetness, but I do not know how little sugar you can add and still
get adequate carbonization.]
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clean 2 liter plastic soft drink bottle with cap. (I do not recommend glass bottles because of the risk of explosive shards of glass...) funnel 1 cup measuring cup 1/4 tsp measuring spoon 1 Tbl measuring spoon |
1 cup table sugar [alias cane sugar or sucrose]
Zatarains's Root Beer Extract (1 tablespoon) (When I could not find it locally, I
ordered a case of 12 bottles for $18 from Zatarain's, New Orleans, LA
70114. Previously, I had used Hires extract.) powdered baker's yeast (1/4 teaspoon) (Yeast for brewing would certainly work at least as well as baking yeast.) cold fresh water |
INSTRUCTIONS:
NOTE: There will be a sediment of yeast at the bottom of the bottle,
so that the last bit of root beer will be turbid. Decant carefully if you
wish to avoid this sediment.
A WORD ABOUT THE ALCOHOL IN
HOME MADE ROOT BEER (OR
GINGER ALE ): I have received numerous inquiries about whether
there might be alcohol in this home made soft drink. The answer is yes,
but... We have tested in our lab the alcoholic content which results
from the fermentation of this root beer and found it to be between 0.35 and
0.5 %. Comparing this to the 6% in many beers, it would require a person
to drink about a gallon and a half of this root beer to be equivalent to
one 12 ounce beer. I would call this amount of alcohol negligible, but for
persons with metabolic problems who cannot metabolize alcohol properly, or
religious prohibition against any alcohol, consumption should
be limited or avoided. However, there are many high school biology labs who
have made this beverage without any problems. If you are one of these, I
am interested to hear about your conclusions.
Send Email to: FANKHADB@UC.EDU