Development of tools and procedures to improve the consistency of farmstead cheeses

Inherent variations in milk composition, processing and environmental conditions in cheese manufacture can lead to inconsistent and poor quality cheese. For farmstead and small-scale artisanal cheesemakers this can have a significant economic impact on their business and take up considerable time in troubleshooting. The purpose of this study is to help farmstead cheesemakers define and measure quality parameters of their cheeses, understand how these variations impact their cheeses, and learn how to adjust their practices to consistently make better cheese.

This study begins by working with the cheesemakers to determine measurable parameters that define the premium qualities of their cheese. Two model cheeses will be evaluated: a pasteurized mozzarella curd that is frozen immediately after manufacture for stretching a later date, and a raw milk, semi-soft, aged cheese. Variables in milk composition, the cheesemaking process and cheese quality will be tracked for12 months to capture seasonal variations. These variables will be correlated to determine which factors have the most influence on quality and consistency. Based on these findings, recommendations will be made to the cheesemakers on how to adjust their processes to improve their products. Cheese processing and product quality variables will be tracked for an additional 6 months to monitor the results of the recommendations.

Outcomes of this project include improved product quality for the cheesemaker collaborators, and the generation and dissemination of extension fact sheets, and model data collection and tracking templates that can be used by other cheesemakers to improve their processes and products.

Project objectives from proposal:

Solution
To improve the consistency of farmstead cheeses, two questions will be addressed by this project:

What measurable markers define optimal quality and consistency for the selected cheese?

What variables in milk composition, milk quality, the cheesemaking process, and environmental conditions are most important to monitor for the consistent production of the cheese?

The specific project objectives are:

Using two model cheeses (a raw milk, semi-soft, aged cheese and mozzarella curd that is frozen for future stretching), determine the key measurable and qualitative parameters for defining the optimal characteristics of the cheeses at the time of consumption.

Develop a tracking system to record the milk composition and quality measurements, processing and environmental conditions, and cheese characteristics.

Track milk composition and quality data, processing and environmental conditions, and cheese characteristics over one year to capture seasonal effects.

Correlate manufacturing variables with cheese quality to determine which variables are most important, and make recommendations on how to adjust the cheese making process to compensate for the variations that influence consistency.

Generate fact sheets and data tracking templates that can be modified by other cheesemakers to meet their specific needs.

Methods

Objective 1: Using 2 model cheeses (a raw milk, semi-soft, aged cheese and mozzarella curd that is frozen for future stretching), determine the key measurable and qualitative parameters for defining the optimal characteristics of the cheeses at the time of consumption.

An initial sensory evaluation session will be held with each cheesemaker to discuss the optimal flavor and texture characteristics of the cheeses. The cheesemaker will provide several cheeses that represent a range in quality to determine control limits. The cheeses will be evaluated by the cheesemakers, the Penn State researchers, and others that may assist the cheesemaker with routine evaluations.

A lexicon of flavor and texture descriptors will be developed for each cheese, using methods described by Drake et al. (Development of a Descriptive Language for Cheddar Cheese. 2001. J. Food Sci. 66(9):1422-1427). Descriptors will be drawn from those found in the literature and used in cheese competitions for similar type cheeses. Score sheets will be developed for the cheesemakers to quantitatively assess the sensory aspects of the cheeses during the study.

For the semi-soft ripened cheese, determination of other measurable quality indicators will be based on a discussion with the cheesemaker on the cheesemaking process and current problems. Variables to monitor include the pH and moisture content of the cheese at different stages of aging, and temperature and humidity of the aging facility. Cheeses chosen for the initial on-site evaluation will be measured for these markers to determine the control limits for optimal quality.

The key parameter for stretching mozzarella is a curd pH of 5.1 to 5.3. The mozzarella curd is sold frozen, to be thawed and stretched by the end user. At the initial session, the manufacturing process will be evaluated to determine when pH measurements should be taken and to see if additional monitoring of the process is needed.

Objective 2 - Develop a tracking system to record the milk composition and quality measurements, processing and environmental conditions, and cheese characteristics.

The batch sheets currently used by the cheesemakers to record the cheese making process and other factors will be reviewed. Modifications to these forms or development of new ones will be made as needed to ensure that all key variables are recorded. Worksheet templates will be developed using Microsoft Word.

Microsoft Excel spreadsheets will be developed to record milk composition (fat, protein, lactose, solids content) and quality parameters (standard plate and somatic cell counts), cheese making process variables (pH, times, temperatures), environmental conditions (temperature, humidity), and cheese quality characteristics (flavor and texture score, pH, moisture content). Graph templates will be developed within Excel to monitor and compare trends in raw material and process variables with finished product measurements.

Standard procedures will be developed for data collection by the cheesemakers and for secure transfer of data to Penn State for analysis. The procedures will be shared with the cheesemakers during an on-site visit to ensure that they understand the procedures and how and when to collect and report the data.

Objective 3 - Track milk composition and quality data, processing and environmental conditions, and cheese characteristics over one year to capture seasonal effects.

The cheesemaking process, environmental, and cheese quality data will be collected by the cheesemakers and sent to Penn State according to procedures and worksheets developed in Objective 2. Milk and cheese samples will be shipped periodically to Penn State for analysis of the parameters determined in Objective 2. The cheesemakers receive data on milk composition from their dairy cooperatives and will share the information with Penn State for tracking. All data will be tracked in Excel spreadsheets by Penn State for one year to capture seasonal trends.

One month after data collection begins, the researchers will visit the cheesemakers to discuss and observe the data collection process, and refine worksheets and procedures if necessary. The researchers will collect milk and cheese samples for analysis at Penn State. Four additional visits will be made to the cheesemakers over the course of the study period to observe and collect data and samples under different seasonal conditions. At each on-site visit, Penn State will sample the cheesemaking and aging room environments using ATP swabs as an indicator of cleaning and sanitizing practices.

Objective 4 - Correlate manufacturing variables with cheese quality to determine which variables are most important, and make recommendations on how to adjust the cheese making process to compensate for the variations that influence consistency.

All process and environmental variables will be graphed in Excel to determine trends over the course of one year of cheese making and aging. These trends will be qualitatively correlated with cheese quality parameters to identify the variables that are most influential on cheese consistency. Information published in the scientific literature will be reviewed and summarized to provide straightforward recommendations on how to adjust the cheesemaking process to compensate for the key variables identified.

Process and composition data will be collected for an additional 6 months following the implementation of the recommendations. The data will be analyzed as above to determine if changes in practices resulted in improved quality and consistency of the cheese.

Statistical analysis based on replications of individual cheesemaking days will be discussed with the Penn State Statistical Consulting Center, but may not be feasible due to issues inherent in following commercial farmstead cheesemaking operations compared to a controlled laboratory study. The ability to gather replicates based on seasonal variation is beyond the scope of this project.

Objective 5 - Generate fact sheets and data tracking templates that can be modified by other cheesemakers to meet their specific needs.

The protocols and worksheets used in this study will be modified to remove information that is specific to the study collaborators. Generalized guidelines for quality determination and process control will be published as fact sheets. Data collection and tracking templates will be made in Word and Excel so that they can easily be modified by any cheesemaker to meet their needs. These materials will accessible to all cheesemakers from the Penn State Dairy Processing website.

Timetable

The project timeframe is 2 years, May 1, 2015 to April 30, 2017.

May 1 – August 30, 2015

Objective 1 completed: The measureable parameters for cheese quality and consistency will be determined. On-site meetings with Penn State researchers and the cheesemakers conducted to determine a sensory lexicon and analytical parameters needed to define the cheese quality and consistency. Cheese samples will be analyzed at Penn State to determine baseline values for tracking consistency.

Objective 2 completed: Data collection procedures, worksheets and tracking spreadsheets will be modified or created, and finalized by Penn State. The procedures and worksheets will be shared with the cheesemakers at an on-site visit in preparation for data collection.

September 2015 – August 2016

Objective 3 completed: Data on raw milk, cheese making, aging, and environmental variables collected by cheese maker and sent to Penn State. Cheese and milk samples sent to Penn State for compositional analysis. All data entered into tracking spreadsheets by Penn State. Penn State visits to cheesemakers four times to observe data collection, collect samples, and swab facilities for sanitation indicators.

July 2016 – September 2016

Objective 4: Analysis of milk and cheese composition and processing variables collected in the study to determine which parameters are most influential on cheese consistency conducted by Penn State. Penn State reviews scientific literature to develop recommendations for cheesemakers on how to modify processing to improve cheese consistency based on key variables identified.

September 2016 – March 2017

Objective 4 completed: Cheesemakers implement recommendations. Cheesemakers collect data on milk and cheese processing parameters and send to Penn State for analysis. Cheese and milk samples sent to Penn State for compositional analysis. Data entered into tracking system by Penn State and evaluated for improvement of consistency based on recommendations.

March 2017 – April 2017

Objective 5 completed: Penn State makes generic procedures and templates for determining cheese quality parameters, data collection worksheets and data tracking spreadsheets. Penn States distribute materials to cheesemaker collaborators, and publishes and posts materials on Penn State website.

Results Dissemination

The procedures, data collection and evaluation tools developed in this project will be shared with the participating collaborators during the course of the project in order to pilot test and refine the materials.

Communication pieces for other farmstead and artisanal cheesemakers will be in the form of extension fact sheets, model data collection forms and spreadsheet templates. The fact sheets may be published through Penn State Ag Cooperative Extension. The fact sheets will be made available directly to the public on the Penn State Extension Dairy Food Processing website (http://extension.psu.edu/food/dairy). The data collection forms and spreadsheet templates will be made available through the same website. These materials will be incorporated as supplemental materials in the annual Penn State Science and Art of Cheese Making Short Course (international attendance), and into future workshops offered by Penn State that are targeted to cheesemakers.

Availability of the materials will be announced on the Dairy Food Processing website and in the Penn State dairy foods newsletter, and through other cheesemaker networking groups such as the Chester County (PA) Cheesemakers, the Pennsylvania Association for Sustainable Agriculture (PASA) cheesemakers group, and regional cheese guilds.

The results of the overall project will be submitted as a research in brief article to the Journal of Extension, or other appropriate scientific publication, for publication for cheesemakers, educators and the extension community.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.