Avoid wine spoilage with in-house wine testing— an investment for quality

Importance of the topic

Effective control of vinification depends on timely, accurate chemical analyses across the production chain from grape harvest to bottling. In-house wet-chemical testing enables winemakers and oenologists to make rapid process decisions that reduce spoilage risk, protect product quality, and optimize yields. Decentralized laboratory capability shortens analytical turnaround, lowers per-test costs compared with external services, and supports continuous quality assurance throughout fermentation, aging and bottling.

Objectives and overview of the document

This document presents the rationale for establishing in-house wine testing and summarizes the key analytes recommended for monitoring at successive process stages. It positions discrete wet-chemistry analyzers as a practical solution for enology labs, highlighting benefits such as rapid turnaround, cost savings, operational flexibility and improved market competitiveness.

Used methodology and testing scope

Recommended approach: perform core wet-chemical assays in-house using an easy-to-operate discrete analyzer platform. This enables batch processing of multiple parameters with minimal sample handling and predictable throughput. Typical workflow points for sampling and testing are: harvest (grape juice), extraction/pressing, fermentation, filtration, aging, and bottling. At each stage, targeted analyses guide operational control (e.g., SO2 adjustment, acid corrections, nutrient additions, microbial risk assessment).

Key analytical classes covered: organic acids (tartaric, malic, lactic, succinic, acetic), carbohydrates and residual sugars (glucose, fructose, sucrose), sulfur dioxide (free and total), pH, total and volatile acidity, glycerol, gluconic acid, NOPA (primary amino nitrogen surrogate), ammonia, color/phenolic metrics, metals (iron, calcium), ascorbic acid, alcohol (low-range), and total polyphenols.

Used instrumentation

Discrete wet-chemistry analyzers (example noted in the source material: Thermo Scientific Gallery discrete analyzer). Core features that make this class of instruments suitable for winery QC:

• Discrete reagent-based assays for a broad panel of enology parameters.
• Automated sample-reagent handling and photometric or enzymatic endpoints for reproducible results.
• User-friendly software and workflows for routine lab staff and oenologists.
• Reduced cost per analysis through batch processing and consolidated reagent use.
• Flexible scheduling to provide rapid turn-around when process decisions are required.

Main results and discussion

The source emphasizes six top spoilage-related parameters that should be prioritized to prevent product loss and sensory defects: pH, volatile acidity, total acidity, residual sugars, residual malic acid, and free/total SO2. Monitoring these parameters at specific process stages provides actionable information:

• Harvest/juice: assess sugars, organic acids, gluconic acid (botrytis indicator), sulfur dioxide baseline, and nutrient proxies (NOPA, ammonia) to plan fermentation and SO2 additions.
• Early fermentation: follow sugar depletion (glucose/fructose), malic acid decline, glycerol production, volatile acidity and SO2 to detect stuck or sluggish fermentations and microbial spoilage.
• Post-fermentation/filtration and aging: monitor residual sugars, free/total SO2, polyphenols and color, metal content, and off-flavor precursors to decide on fining, stabilization and SO2 management.
• Bottling: final checks for alcohol level, SO2, residual sugars and pH ensure stability and regulatory compliance.

Operational discussion: In-house testing reduces delay between sampling and decision, which is critical for actions such as SO2 adjustment, acid additions, and corrective enological treatments. The breadth of analytes listed supports both preventive and corrective measures to limit spoilage pathways (e.g., acetic acid/volatile acidity produced by acetobacter or spoilage yeasts, or premature malolactic fermentation).

Benefits and practical applications

Primary practical advantages of implementing in-house wine testing:

• Rapid turn-around: faster response to dynamic fermentation events and quality deviations.
• Cost savings: lower per-test cost and elimination of freight and external lab delays for routine testing.
• Versatility and flexibility: run customized panels appropriate to process stage and production scale.
• Quality assurance: tighter control over SO2 management, acidity, residual sugar and microbial risk factors that directly affect shelf life and sensory quality.
• Market advantage and profitability: consistent product quality protects brand reputation and can lower wastage and rework.

Practical implementation: integrate discrete analyzers into the winery QC workflow with defined sampling points and decision thresholds. Train staff in routine operation and maintenance, and establish data logging to support trend analysis and regulatory traceability.

Future trends and potential applications

Emerging and likely developments in enology analytics include:

• Greater automation and integration: on-line or at-line sensors combined with discrete analyzers for mixed sampling strategies that improve time-to-result and reduce manual handling.
• Miniaturized and portable platforms: field-capable devices for rapid harvest-site assessments.
• Expanded multiplexing and chemometrics: combining multi-parameter datasets to predict fermentation trajectories and spoilage risk using machine learning.
• Improved enzymatic and biosensor assays for low-level analytes (e.g., trace volatile acids, SO2 speciation) with better specificity.
• Cloud-enabled data management: centralized quality dashboards for multi-site wineries and real-time decision support.

Conclusion

Establishing an in-house wet-chemistry testing capability is a practical investment for modern wineries. Discrete analyzers deliver a balance of throughput, ease of use and analytical scope that supports critical process control from harvest to bottling. By prioritizing key spoilage parameters and integrating routine testing into decision-making, wineries can reduce spoilage, optimize interventions, and maintain consistent product quality while achieving cost efficiencies.

Reference

Thermo Fisher Scientific. Promotional material on in-house wine testing using Gallery discrete analyzers. 2020.