Using Paper Chromatography to Monitor ML Fermentation in Wine

Summary

In this instructional video, the presenter outlines a step-by-step process for conducting a malolactic fermentation chromatography test to determine if fermentation is complete. Using a specially designed chromatography paper and various acid standards—malic, lactic, and tartaric—samples of four different wines are applied to the paper. After allowing the samples to dry, the paper is developed in a solution for 6 to 8 hours, revealing distinct spots corresponding to each acid. The results indicate that malolactic fermentation is still occurring, prompting the presenter to plan a follow-up test in a few weeks to assess further progress.

Takeaways

• 🧪 This test is used to determine if malolactic fermentation (MLF) in wine is complete.
• 📝 The procedure begins with marking chromatography paper to indicate where to place samples and standards.
• 🔬 The standards used in the test are tartaric acid, lactic acid, and malic acid.
• 💧 Each sample must be applied with a separate capillary tube to avoid contamination.
• ⏳ Samples are allowed to dry for approximately 30 minutes after application.
• 📏 The chromatography paper is then folded into a cylinder for development.
• 💡 The developer solution is filled to half the height of the cylinder, ensuring it does not touch the samples.
• ⏲️ Development time for the chromatography is between 6 to 8 hours or overnight.
• 📊 The results are analyzed by observing the chromatogram for the presence of malic and lactic acids.
• 🔄 A follow-up test is recommended in 2-3 weeks to track the progress of MLF.

Q & A

What is the primary purpose of conducting the chromatography test mentioned in the transcript?

The primary purpose of the chromatography test is to determine if malolactic fermentation (MLF) in wine is complete.

What standards are used in the chromatography test, and why are they important?

The standards used are tartaric acid, lactic acid, and malic acid. They are important because they serve as reference points to identify the presence and concentration of these acids in the wine samples.

How are the samples applied to the chromatography paper?

Samples are applied to the chromatography paper using capillary tubes, ensuring that a new tube is used for each acid to prevent contamination.

What is the significance of using different capillary tubes for each sample?

Using different capillary tubes for each sample prevents contamination, ensuring that the results of the chromatography test accurately reflect the acids present in each specific sample.

What is the process of developing the chromatography paper after applying the samples?

After the samples dry, the paper is folded into a cylinder and placed in a developer solution, which should not touch the spots on the paper. The developer allows the capillary action to occur, raising the solution through the paper.

How long should the chromatography paper be left in the developer, and what should be done afterward?

The chromatography paper should be left in the developer for 6 to 8 hours. After this period, it is removed and hung to dry for further observation of the results.

What do the results of the chromatography test indicate about malolactic fermentation?

The results indicate the presence and relative concentration of malic acid and lactic acid. A high presence of malic acid suggests that fermentation is still occurring, while an increase in lactic acid would indicate that malolactic fermentation is nearing completion.

What was observed in the chromatogram regarding the acids present?

In the chromatogram, the spots for tartaric acid, malic acid, and lactic acid were visible, suggesting that malolactic fermentation was ongoing, with malic acid still present.

What follow-up actions were planned after the chromatography test?

A follow-up test is planned in 2 to 3 weeks to observe changes in the acid levels, specifically looking for a decrease in malic acid and an increase in lactic acid.

Why is it important to monitor malolactic fermentation in wine production?

Monitoring malolactic fermentation is important because it helps winemakers ensure the desired flavor profile is achieved, as the conversion of malic acid to lactic acid affects the taste and stability of the wine.