Wine Evaluation & Testing Facilities

This page contains information on wine evaluation and testing facilities in North Carolina, including soil sample testing, petiole sampling and wine sample analysis.

Appalachian State University Enology Services Lab
Accepts samples of grapes, wine and must for analysis. They are currently providing preliminary analyses including Brix, Titratable Acidity (TA), pH, Nitrogen (FAN + NH4), Malic Acid, Soluble Solids, Glucose + Fructose, Volatile Acidity (VA), SO2 (Total and Free) and Alcohol. They will provide immediate turnaround leading up to harvest, during crush and throughout wine production when timely analysis is most important. Please see the Sample Submission page for more details.

There is no fee for current analyses as listed. Please contact Hollis Price, wine analysis coordinator, at or (828) 406-6014, regarding inquiries for more detailed analyses (petiole analysis, phenolics, aroma compounds, microbiology panels, etc.). 

Soil Sample Testing
Contact your County Cooperative Extension Agent or call Agronomic Services at (919) 733-2655 for instructions. Service is free to residents but may take several weeks. 

Petiole Sampling
Full bloom is the time of year to take petiole samples from your vineyard for nutrient level testing. Petiole sampling and testing is a practice that all grape growers should implement each year. Test results can diagnose a nutritional deficiency or toxicity in the vineyard that may otherwise go unnoticed or misdiagnosed. Such a nutritional imbalance could reduce the quantity and quality of the crop and/or impair the health of the vines. By taking petiole samples for testing, growers may, in some cases, be able to correct a nutritional imbalance that growing season.

A state-of-the-art plant testing laboratory in the Agronomic Division of NCDA&CS receives your samples, takes only two business days to analyze the sample and send you your results.

Stop by your County Cooperative Extension office to pick up sampling kits or contact NCDA&CS Agronomic Services at (919) 733-2656.

Follow these instructions for taking samples:

  1. Sample at full bloom (when two thirds of the flower caps have been shed). 

  2. Collect one sample unit from each variety in each planting block. If you have several varieties within a block, you may want to sample only one variety. Do not mix petioles from different varieties within a sample unit. 

  3. Collect 100 petioles per sample unit (the petiole is the small shoot which connects the leaf to the main stem). Collect no more than one to two petioles per vine. Immediately separate the petiole from the leaf and place in a labeled paper bag or envelope.

  4. From each sampled vine, collect a petiole that is opposite a fruit cluster. If there is no fruit, pick a healthy leaf at the second or third node from the base of the shoot. 

  5. DO NOT SAMPLE a) diseased plants, b) heat- or moisture-stressed plants, c) within seven days after spraying, unless there has been a good rainfall d) early in the morning or on extremely cloudy days.

  6. Place plant tissue samples inside the large envelope provided with the sampling kit. Do not wrap or enclose sample in plastic bags. 

Wine Analysis
Having trouble with your wine? Submit a sample to the North Carolina Sensory Evaluation Panel. Provided by NC State and Cooperative Extension services, the evaluation panel is composed of nine winemakers and industry experts from across the state. They will screen your wine for known defects, conduct laboratory tests and provide tips and suggestions for making the best wine possible. Contact the NCSU Department of Food Science at (919) 515-2951.