Beer and wine, products of fermentation using yeast, are the most widely accepted products of biotechnology for consumption during the holiday season. Other more controversial food items are products of agricultural biotech, such as genetially modified (GM) vegetables or the oversized turkeys we now have, developed through traditional breeding. However, you may be surprised to learn that there are many long-standing traditions for Christmas meals, that require a knowledge of either how to use microorganisms, or control their growth. Are any of these on your holiday table?
Cheese – of course not necessarily a tradition at Christmas time, cheese is an example of biotechnology in the dairy industry and cheese balls are nearly a staple at holiday parties. Then there is the wine and cheese party, or those who enjoy a slice of cheddar with their apple pie following turkey dinner. Cheese is obtained by letting milk become acidified, usually by bacteria, or is also sometimes made using molds.
Jams and Jellies, such as might be found in a Christmas Yule Log cake, or cranberry sauce, are products of biochemical reactions, although early chefs probably did not understand the reactions taking place in their pots. When mashed fruit is boiled in sugar and water, a chemical reaction takes place between the sugar, acids from the fruit, and pectin, a polysaccharide (polymer of sugars) found in the fruit. Once the reaction has taken place and mixture is cooled, it will form a semi-solid gel. Our knowledge of enzymes has advanced since the advent of jelly, such that we now use pectinase enzymes to prevent the gelling reaction from taking place. This is key to making home-made fruit wines, and preventing them from clouding.
Wassail – Ever wonder what they meant in the traditional Christmas song Here We Come A-Wassailing…? Basically it means drinking – a beverage made originally from spiced wine and later with spiced British ale, often enriched with cream and heated until frothy on top (called Lamb's Wool). Many more variations exist, most likely dependent on the wealth of the maker and available ingredients.
Christmas Pudding – otherwise known as Plum Pudding or Christmas Cake, is traditionally made early, from a week ahead to as much as a year ahead, and allowed to age. The Sunday before the beginning of Advent is known as Stir-up Sunday as it is the tradition to make the pudding then. To age the cake, it is doused in some kind of alcohol and wrapped in cheesecloth that has also been soaked in alcohol. The alcohol seems to serve a dual purpose – both preserving the cake and adding enhanced flavor as it soaks in over time. Note: if mold appears on the cake, according to The Encyclopedia of Country Living, that's alright, just trim it off and eat the cake.
Stollen – is a traditional cake made in Europe, particularly Germany, for the twelfth night, twelve days after the birth of Christ. The cake might also be called Christollen. Although many varients exist, the basis of Stollen is the sweet yeast-based dough and addition of dried fruit and sometimes nuts. Another traditional Christmas bread requiring yeast is the Italian Pannetone.
Ross, A. Wassailing on New Years. The Journal of Antiques Collectables. December 2002.
Emery, C. The Encyclopedia of Country Living. Sasquatch Books, 2003.