Olives and Alcohol

Canvas Announcement

• Instructor encouraged students to refer to the answer key available on Canvas for self-assessment and feedback.

• The feedback provided on quiz scores consisted of median and range statistics:

  • Quiz total points: 20

  • Range of scores: 3 to 20

    • Indicates significant variability in note-taking and study habits among students.

  • Median score: 14

    • Signifies that students scoring 14 or higher are in the top half of the class.

Fermentation Overview

• Sauerkraut and Pickles: Discussed changes in physical technology and salting methods relevant to fermentation processes.

• General Fermentation: Transitioning to broader aspects of food fermentation, specifically vegetable fermentation and its commercial significance.

• Notable examples included in the field:

  • Coexistence of grape (for wine) and olive productions owing to climatic conditions.

Olive Fermentation Processes

• Types of olives discussed:

  • Spanish, Sicilian, Greek, and Californian olives.

• Pretreatment of Olives:

  • Bitter compound present: Oleuropein (a bitter glycoside).

    • High levels lead to unacceptable taste.

• Lye Treatment:

  • Sodium Hydroxide concentration: 0.9% to 1.25%.

  • Effect: Breaks down oleuropein to reduce bitterness.

Fermentation Process of Olives

• Steps involved:

  1. Lye treatment followed by thorough washing to eliminate sodium hydroxide.

  2. Use of brine solution:

     • Concentration: 16% to 20%.

     • Careful control to avoid undesired lactic acid bacteria.

• Fermentation Environment:

  • Smaller, controlled environments such as barrels for fermentation.

  • Duration: generally takes a month or more.

• Post-Fermentation Treatment:

  • Addition of alfalfa to prevent surface yeast and mold growth.

  • Surface oiling for aesthetics and quality.

Spoilage in Olive Fermentation

• Main spoilage concerns include:

  • Enzymatic breakdown leading to softening.

  • CO2 buildup causes 'fisheye' defects (similar to blistering in cucumbers).

  • Butyric acid spoilage from unintended microbes.

• Unique spoilage term for olives: "Zapatera"

  • Happens when pH does not drop below 4.

  • Indicators include foul smells and undesired microbes.

Summary of Olive Fermentation Industry

• Green olives account for approximately half of global production, notably by Spain.

• Commercial Practices:

  • Use of sodium hydroxide for initial treatment, followed by multiple washings.

  • Salt concentration is adjusted post-fermentation to inhibit spoilage microbes before commercialization.

Alcohol Fermentations Overview

• Transition to the next commodity: Alcohol Fermentations, specifically beer and wine production.

• Alcoholic beverages likely represent humanity's earliest form of fermentation, utilizing sweet fruit juices for spontaneous yeast fermentation.

Beer Production History

• Historical evidence of beer making dating back over 6,000 years, with references in Babylonian clay tablets.

• Significant contributor to yeast starter culture development: Emile Christian Hansen (established in 1883).

• Connection to advancements in the understanding of microbial fermentation by Louis Pasteur in the 1860s.

Yeast in Beer Fermentation

• Types of Yeast:

  • Top Fermenters: Float to the surface, used in ales, prefer warmer temperatures.

  • Bottom Fermenters: Settle at the bottom, used in lagers, prefer cooler temperatures.

German Purity Law

• Law stipulates four essential ingredients in beer production:

  1. Malt

  2. Water

  3. Yeast

  4. Hops

• Any additional ingredients lead to penalties.

Raw Materials and Malting Process

• Malting activates enzymes in grains to release sugars necessary for fermentation.

• Steps in malting include:

  1. Hydration of grains.

  2. Sprouting and subsequent arresting of germination process.

  3. Kiln drying to preserve the malt.

Mashing and Brewing Process

• Mashing involves:

  • Hydration of malted grains and addition of starch adjuncts (optional, depends on brewery's style).

  • Creation of "wort" through the breakdown of starch.

• Boiling the Wort:

  • Duration varies to ensure microbial safety and create desired flavors.

  • Addition of hops for flavor and antimicrobial properties.

Hops in Beer Production

• Hops are flowers used for flavor and preservation effects in beer.

• Historically significant to the development of beer flavor profiles.

• Bacteriostatic vs. Bacteriocytic:

  • Hops are primarily bacteriostatic for gram-positive bacteria (important in beer preservation).

Fermentation and Aging of Beer

• Post-boiling process involves cooling and adding yeast.

• Fermentation phases can vary by style (ales vs. lagers) and last several days.

• Aging and clarification processes vary across different beer types.

Explanation of IPA (India Pale Ale)

• Originates from historical necessity for long preservation during sea voyages.

• Higher hop content enabled stability and taste retention over long transport durations.

Conclusions and Future Topics

• Next topic will focus on spirits and vinegar production as follow-ups to alcohol fermentations.

Note: Throughout the discussion, the implications of various fermentation technologies, environmental controls, and the economic aspects of each fermentation method were heavily stressed, underscoring their importance to modern practices in food and beverage production.