Making Root Beer

David B. Fankhauser, Ph.D.

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 .) Other flavors can be substituted for the root beer extract. Try using a tablespoon of vanilla instead of the extract for a cream soda, and ginger and lemon for ginger ale.


IMPORTANT SAFETY CAUTION: Refrigerate these bottle-fermented soft drinks as soon as the bottle feels hard. Especially in the summer, after a week or so, there is a risk of explosion!

[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. I do not know how little sugar you can add and still get adequate carbonization, but 1/2 cup of sugar/ 2 liters makes plenty of carbonation.]

EQUIPMENT
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

SUPPLIES
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:
1) Assemble the necessary equipment and supplies

2) With a dry funnel, add in sequence:
1 level cup of table sugar (cane sugar) (You can adjust the amount to achieve the desired sweetness. Cutting the sugar in half still produces adequate carbonation with much less sweetness.)

3) Add: 1/4 teaspoon powdered baker's yeast ( fresh and active)(Fleischmann's or other brand)

4) You can see the yeast granules on top of the sugar.

5) Shake to distribute the yeast grains into the sugar.

6) Swirl the sugar/yeast mixture in the bottom to make it concave (to catch the extract).

7) Add with funnel:
1 Tbl of root beer extract (I prefer Zatarain's, but Hires, etc. will work.)on top of the dry sugar

The extract sticks to the sugar which will help dissolve the extract in the next steps.

9) Half fill the bottle with fresh cool tap water (the less chlorine, the better). Rinse in the extract which sticks to the tablespoon and funnel. Swirl to dissolve the ingredients.

10) Q.s. [fill up] to the neck of the bottle with fresh cool tap water, leaving about an inch of head space, securely screw cap down to seal. Invert repeatedly to thoroughly dissolve.

If you leave it in a warm temperature longer than two weeks, you risk an explosion...

11) Place at room temperature (RT)about three to four days until the bottle feels hard to a forceful squeeze. Move to a cool place (below 65 F). refrigerate overnight to thoroughly chill before serving. Crack the lid of the thoroughly chilled root beer just a little to release the pressure slowly.

NOTE: Do not leave the finished root beer in a warm place once the bottle feels hard. After a couple weeks or so at room temperature, especially in the summer when the temperature is high, enough pressure may build up to explode the bottle! There is no danger of this if the finished root beer is refrigerated.

12) Move to a refrigerator overnight before opening.