The Defects Wheel® for Olive Oil

DIagnose the cause. Improve the oil.

Dr. Richard Gawel's Recognose® Olive Oil Tasting Wheel provides a taxonomy for describing the positive and negative sensory attributes of olive oil. The Defects Wheel® builds upon that foundation.

Created by sensory scientist Susan Langstaff, The Defects Wheel® is a diagnostic field reference that connects each recognized sensory defect with its likely biological, chemical, and production-related causes.

Used by growers, millers, quality assurance professionals, educators, judges, and taste panels throughout the world, it transforms a sensory observation into a practical tool for diagnosing problems, improving production practices, and protecting olive oil quality.

The Defects Wheel® for olive oil  was developed with technical contribution from leading Spanish olive oil researchers, Aparicio and the CSIC-SEXIA Group, and has been continuously in print since 2011.

Follow the Defect Back to Its Source

Every sensory defect has a history.

Some begin in the orchard. Fruit damaged by frost, insects, disease, or delayed harvest may already contain the chemical changes that eventually produce sensory defects.

Others develop during milling. Poor sanitation, delayed processing, excessive malaxation, or unsuitable milling conditions can permanently alter an otherwise exceptional olive oil.

Still others occur after production. Exposure to oxygen, light, elevated temperatures, or improper storage can rapidly diminish even the finest extra virgin olive oil.

The Defects Wheel® helps users trace sensory observations back through the production chain, making it an invaluable reference for diagnosing quality problems and preventing them in future harvests.

A Rotating Volvelle

The Defects Wheel® is produced as a traditional volvelle—a rotating paper reference consisting of two precision-cut printed discs joined with a brass fastener.

As the upper wheel is rotated, each identified sensory defect aligns with detailed technical information describing its origins, associated compounds, and likely causes.

The rotating design allows users to move naturally from sensory observation to diagnosis while tasting, teaching, or troubleshooting production issues.

Unlike laminated aids, the wheel is printed on heavyweight stock to rotate smoothly while remaining lightweight and portable for everyday use.

What You'll Find on The Defects Wheel®

As the wheel rotates, the selected defect aligns with technical information including:

• Sensory descriptors
• Primary biological or mechanical origins
• Compounds associated with the defect
• Chemical formulas
• Typical concentrations found in olive oil
• Approximate odor detection thresholds
• Possible causes
• Corrective actions, where applicable
• Preventive measures to reduce future occurrence

Rather than simply identifying a defect, The Defects Wheel® explains why it occurred and where corrective action should begin.

Reverse Side Reference

The reverse side extends the wheel's educational value with additional reference material for producers, educators, and sensory professionals.

Included are:

• A comparison of the sensory characteristics typically associated with early- and late-harvest olive oils
• An illustrated overview of the nine principal steps in modern extra virgin olive oil production, from harvest through bottling
• Factors influencing the development of sensory defects throughout production and storage
• A concise summary of the IOC's three positive sensory attributes—Fruity, Bitter, and Pungent
• Best practices that help preserve extra virgin olive oil quality from orchard to bottle

Together, both sides make The Defects Wheel® an indispensable field reference for olive oil production and sensory evaluation.

Who Uses The Defects Wheel® ?

The Defects Wheel® was developed for professionals who produce, evaluate, and teach olive oil quality.

It is particularly valuable for:

• Olive growers
• Mill operators
• Olive oil producers
• Quality assurance professionals
• Taste panel leaders and members
• Olive oil judges
• Researchers
• Educators
• Students of sensory science

Serious olive oil enthusiasts will also find it to be a fascinating educational reference.

About Susan Langstaff

Susan Langstaff is an internationally respected sensory scientist specializing in olive oil, wine, and beer evaluation. She previously led the UC Davis Olive Oil Taste Panel, serves on the California Olive Oil Council Taste Panel, and has judged major international olive oil competitions throughout the world.

She is co-editor of Olive Oil Sensory Science (Wiley-Blackwell, 2014), creator of The Defects Wheel® for Olive Oil, and has spent decades helping producers, educators, and sensory professionals improve olive oil quality through the application of sensory science.

Specifications

• Developer: Susan Langstaff
• Format: Rotating volvelle
• Construction: Two precision-cut printed discs joined with a brass fastener
• Material: Heavyweight printed cardstock (not laminated) in a glassine envelope
• Operation: Rotating upper wheel aligns sensory defects with their likely causes, associated compounds, and supporting reference information
• Developed, printed and assembled in the United States
  

Reference Information Includes

• Sensory descriptors
• Biological and mechanical origins
• Associated compounds
• Chemical formulas
• Typical concentrations
• Approximate odor detection thresholds
• Corrective and preventive guidance
• Production reference information on reverse

Intended Audience

Professional producers, millers, sensory panelists, judges, educators, researchers, and advanced enthusiasts

Availability

Stocked in Northern California, The Defects Wheel® typically ships within one business day.

Domestic orders ship throughout the United States.

International Shipping

Although American Olive Farmer does not currently ship olive oil or other food products internationally, I personally assist colleagues outside the United States with orders for professional sensory evaluation supplies.

Because these orders are prepared individually, international customers are asked to contact me before placing an order. I'll gladly provide a shipping quotation and estimated delivery time.

Customers are responsible for any customs duties, VAT, brokerage fees, or other import charges assessed by their country.

Canada

Canadian customers are encouraged to order through our authorized Canadian representative, Emily Lycopolus at the Olive Oil Critic:  emily@oliveoilcritic.com

Ordering through Emily may reduce shipping costs, customs processing, brokerage fees, and delivery times.