Wine Program - Collaborative Testing Services, Inc. - Providing Worldwide Interlaboratory Testing Since 1971.

Proficiency testing has an important role in any laboratory's quality system. In recognition of this the American Society for Enology and Viticulture (ASEV) has committed to a formal program of quality assurance testing for the wine industry. The ASEV - CTS Wine Interlaboratory Testing Program has been operating annually since 1999, and strives to provide information that is useful on all levels, from independent wineries through to multi-site labs.

The ASEV - CTS Wine Interlaboratory Testing Program currently offers the following 10 properties for each testing round:

Alcohol by Volume
Total Sulfur Dioxide
Free Sulfur Dioxide
Titratable Acidity
Volatile Acidity

Specific Gravity
pH
Reducing Sugar
Malic Acid
Glucose + Fructose

In addition, two research properties are included in each testing round. Previous properties included but were not limited to: lead content, copper content, dissolved oxygen, dissolved carbon dioxide, potassium content, iron content, and calcium content.

Each participant is sent two 750mL bottles of similar wines for testing in his or her laboratory. CTS analyzes the results and issues individual and group reports to all participants. The analysis of laboratory data is based on consensus statistics, comparing each laboratory's measurements to the Grand Mean for that property. Testing is conducted three times a year (Spring, Summer, Winter), providing laboratories with an on-going quality assurance tool for the evaluation of their performance. For more detailed information, please refer to the Program History page.

The following features are available to those labs participating in the Wine Program

Individual reports provide an in-depth look at the most recent testing round. These reports are designed to present a large amount of information in an easy to follow format. Features include an easy to interpret graph, which plots your results compared to all other labs reporting for each property. A trend chart also tracks up to 18 months of previous testing, providing the essential information needed for any ongoing quality assurance program. An example can be found on the Sample Report page.

The Web Summary Report allows labs to see the results for all participants in a test. Web Summaries are posted on the CTS Web site when the Individual Report for that cycle is mailed. Results are posted using a randomly generated Webcode, allowing participants to check their results against other participants while protecting confidentiality.

CTS realizes that some lab managers may oversee more than one site enrolled in the wine program. The Quality Manager system assists with the quality management of multiple sites by providing them with a summary comparing the results of their labs for each testing round. An example of this report can be found on the Sample Report page.

For tests such as SO₂ and Ethanol, CTS recognizes that different analysis techniques within a test can yield different results. While the results are still grouped together for the Individual Report, CTS also posts a Method Breakout to provide additional information to the labs in these tests. These results are posted along with the Web Summary Reports on the CTS Web site and can be accessed by labs looking for more detailed information on this property. Further analyses of these tests can be found on the Technical Topics page.

If you have questions regarding any aspect of the ASEV - CTS Wine Interlaboratory Testing Program, please contact the program coordinator directly through this link.