Glossary of Fermentation Terms

Vocabulary flashcards covering key fermentation terminology, processes, and concepts from the lecture notes.

Aerobic Fermentation

Fermentation that occurs in the presence of oxygen. Yeasts and bacteria may use oxygen to generate energy, but this type of fermentation is less common in traditional food fermentation.

Anaerobic Fermentation

Fermentation that occurs in the absence of oxygen. Most food fermentations, such as the production of yogurt, sauerkraut, and alcohol, are anaerobic processes.

Bacteria

Microorganisms that play a crucial role in fermentation by breaking down sugars into acids, gases, or alcohol. Lactic acid bacteria (LAB) are commonly used in the production of yogurt, cheese, and pickles.

Batch Fermentation

A type of fermentation process where all ingredients are combined at the start, and fermentation proceeds until the desired endpoint is reached. No further inputs are added during the process.

Brine

A solution of salt and water used in the fermentation of vegetables (e.g., pickles, sauerkraut) to create an anaerobic environment and inhibit the growth of unwanted microorganisms.

Catalyst

A substance that increases the rate of a chemical reaction in fermentation without being consumed in the process. Enzymes act as natural catalysts in biological fermentation.

Cultured

A term used to describe foods or beverages that have undergone fermentation with specific strains of bacteria, yeasts, or molds, such as yogurt, cultured butter, or kombucha.

Ethanol Fermentation (Alcoholic Fermentation)

A biological process in which yeasts convert sugars into ethanol (alcohol) and carbon dioxide. It is the key fermentation process in brewing beer, winemaking, and distilling spirits.

Enzyme

Proteins produced by living organisms that speed up chemical reactions, such as breaking down sugars in fermentation.

Fermentation

A metabolic process that converts sugars (carbohydrates) into acids, gases, or alcohol through the action of microorganisms such as bacteria, yeast, or molds. Fermentation is used in food preservation and flavor enhancement.

Fermenter

A vessel or container used to carry out the fermentation process, often equipped with temperature and pH controls. Examples include large fermentation tanks in breweries or small home fermenting jars.

Homofermentative

A type of lactic acid fermentation where the primary end product is lactic acid. This process is common in yogurt and some types of cheese production.

Heterofermentative

A type of lactic acid fermentation that produces lactic acid, carbon dioxide, and ethanol or acetic acid as by-products. This process is used in sourdough bread and some types of pickling.

Inoculum

A small quantity of microorganisms (yeasts, bacteria, or molds) introduced into a substance to initiate fermentation. In food production, starters like sourdough or yogurt cultures serve as inoculums.

Kombucha

A fermented tea beverage made by fermenting sweetened tea with a symbiotic culture of bacteria and yeast (SCOBY), producing a slightly effervescent, acidic drink.

Lactic Acid Fermentation

A type of fermentation where bacteria, primarily lactic acid bacteria (LAB), convert sugars into lactic acid. This process is key to making yogurt, kimchi, sauerkraut, and sourdough bread.

Leavening

The process of making dough rise by fermenting sugars to produce gases (e.g., carbon dioxide). Yeast is commonly used to leaven bread, giving it a light, airy texture.

Malolactic Fermentation

A secondary fermentation in winemaking where lactic acid bacteria convert malic acid (which is sharp and tart) into lactic acid (which is smoother and less acidic), softening the wine's taste.

Metabolism

The set of life-sustaining chemical reactions in microorganisms that allow them to convert nutrients, such as sugars, into energy and fermentation by-products.

Microorganisms

Tiny living organisms, such as bacteria, yeast, and molds, that are essential to the fermentation process by converting sugars into various end products (acids, gases, or alcohol).

Probiotics

Live beneficial bacteria and yeasts that promote a healthy gut microbiome when consumed. Fermented foods like yogurt, kimchi, and kefir are rich in probiotics.

Saccharification

The process of breaking down complex carbohydrates (starch) into simple sugars, often using enzymes. This is a key step in brewing and distilling.

SCOBY (Symbiotic Culture of Bacteria and Yeast)

A culture used in the fermentation of kombucha, composed of a complex mixture of bacteria and yeast. SCOBYs initiate fermentation and give kombucha its distinct flavor and fizz.

Starter Culture

A preparation containing microorganisms (bacteria, yeast, or mold) used to start fermentation in food products. Examples include sourdough starter, yogurt culture, and koji for miso.

Submerged Fermentation

A fermentation process where microorganisms grow in a liquid medium, as in the production of beer, wine, and vinegar.

Substrate

The material or substance on which microorganisms act during fermentation. For example, sugar is a substrate for yeast in alcoholic fermentation.

Wild Fermentation

A type of fermentation that occurs naturally, without the addition of commercial or controlled starter cultures. The microorganisms responsible for the fermentation come from the environment, as in wild sourdough or naturally fermented vegetables.

Yeast

A type of fungus used in fermentation to convert sugars into alcohol and carbon dioxide. Yeasts are critical in bread making, brewing, and winemaking processes.