Review Reports

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

1、This study is particularly valuable for its five-year investigation into producing stable no-sulfite-added wines via viticultural interventions and their long-term storage performance, as it clarifies the practical implications of wine ageing and fault development (e.g., Brettanomyces off-odors were observed only in the control). The work shows a degree of originality; however, the Introduction and Discussion do not sufficiently foreground what is novel (e.g., the long-term no-sulfite ageing dataset). I recommend benchmarking the findings against the literature on sulfited wines.

2、The manuscript exhibits structural and logical issues. For example, the abstract uses “non-sulfites addition,” whereas the study concerns no-sulfite-added production; the Introduction shifts from general wine quality to the sulfite question without a smooth transition. The Results section also blends reporting with interpretation (e.g., “as expected” in §3.1), which should be reserved for the Discussion. The Conclusions are concise but overly brief, lacking a treatment of broader implications and future outlook。

3、The Materials and Methods section omits key details, particularly regarding vineyard management (e.g., soil type, irrigation regime, and the date of fruit/berry thinning)。

4、Data presentation is overly uniform, relying almost exclusively on tables and limiting visualization of key patterns (such as sensory attributes or VOC dynamics). Please diversify the presentation by adding figures—for instance, radar plots of sensory descriptors。

5、The Results and Discussion lack depth, and several points are insufficiently developed. For instance, while higher ethyl acetate in wines from berry thinning is noted, it is not connected to sensory outcomes; the attribution of Brettanomyces inhibition to lower alcohol in the control lacks microbiological validation。

6、Please have the English thoroughly copy-edited for grammatical errors and terminological inconsistencies, such as the inconsistent use of “grain reduction (GR)” versus “berry thinning.”。

Comments for author File: Comments.pdf

Comments on the Quality of English Language

Proofread thoroughly or use a native English editor.

Author Response

Dear Reviewer,
Thank you very much for the work you did reviewing this work. Your suggestions have significantly improved the manuscript.
Below, we address your requests. You can see that we have addressed all your requests. You can find the changes made to the document in blue. 

 

1、This study is particularly valuable for its five-year investigation into producing stable no-sulfite-added wines via viticultural interventions and their long-term storage performance, as it clarifies the practical implications of wine ageing and fault development (e.g., Brettanomyces off-odors were observed only in the control). The work shows a degree of originality; however, the Introduction and Discussion do not sufficiently foreground what is novel (e.g., the long-term no-sulfite ageing dataset). I recommend benchmarking the findings against the literature on sulfited wines.

Response: Thank you very much for your valuable comments. Thanks to them, the manuscript has significantly improved. As you can see in the updated version of the article, the introduction has been expanded and the sections on results, discussion, and conclusions have been enhanced

 

2、The manuscript exhibits structural and logical issues. For example, the abstract uses “non-sulfites addition,” whereas the study concerns no-sulfite-added production; the Introduction shifts from general wine quality to the sulfite question without a smooth transition. The Results section also blends reporting with interpretation (e.g., “as expected” in §3.1), which should be reserved for the Discussion. The Conclusions are concise but overly brief, lacking a treatment of broader implications and future outlook。

Response: Thanks to the reviewer's comment, we have revised the terms used throughout the manuscript for consistency. Indeed, the trial involved no-sulfite added production, so this term has been used throughout the manuscript to avoid confusion.

Regarding the comments made in the results section, the authors believe they do not detract from the discussion. In this section, brief comments have been included to clarify or clarify the specific results of each section. However, the discussion section offers a more general discussion, taking into account all the factors already studied.

The conclusions have been rewritten.

 

3、The Materials and Methods section omits key details, particularly regarding vineyard management (e.g., soil type, irrigation regime, and the date of fruit/berry thinning).

Response: Reviewer is right. The Materials and Methods section has been expanded, with particular emphasis on the experimental design and plant material. A detailed description of the vineyard soil has been added, along with the dates of thinning operations and prevailing climatic conditions. Please, check  Section 2.1.

 

4、Data presentation is overly uniform, relying almost exclusively on tables and limiting visualization of key patterns (such as sensory attributes or VOC dynamics). Please diversify the presentation by adding figures—for instance, radar plots of sensory descriptors。

Response: The authors believe that because this is a two-year experiment with three treatments each year and many descriptors/parameters, it's much easier for the reader to display all the results in a table. This way, they can easily compare the results for each parameter. In the case of sensory analysis, using tables significantly reduces the space used in the article and allows for the inclusion of several statistical analyses in a single space, such as Tukey's multiple-range test and the Friedman test; If graphs are used, they should be independent.

 

5、The Results and Discussion lack depth, and several points are insufficiently developed. For instance, while higher ethyl acetate in wines from berry thinning is noted, it is not connected to sensory outcomes; the attribution of Brettanomyces inhibition to lower alcohol in the control lacks microbiological validation。

Response: The differences found in ethyl acetate concentration were minimal enough to be taken into account in the overall results of the article. All treatments were below 2 ppm, while the sensory threshold for the compound to be considered a defect was 18 ppm. We have included this information in the results section to clarify that this increased concentration does not cause wine to exhibit any defects due to this compound. Please review lines 286-287.

Regarding the Brett results, the authors conducted a study based on sensory descriptors, both with a trained panel and a panel of consumers. During the experiment, we did not aim to demonstrate whether Brettanomyces was present or absent in wine samples, but rather the sensory perception it produces at high concentrations, which consumers perceive as a defect. The authors have modified some parts of the manuscript, for example, the conclusions, to reinforce the point that the results obtained refer to the absence of the defect caused by Brettanomyces.

The results, discussion and conclusion sections have been improved.

 

6、Please have the English thoroughly copy-edited for grammatical errors and terminological inconsistencies, such as the inconsistent use of “grain reduction (GR)” versus “berry thinning”.

Response: The reviewer is right. We've rewritten the entire manuscript, unifying the term (treatment). In the manuscript, the treatment performed is, now, “berry thinning” to better reflect the literature.

Reviewer 2 Report

Comments and Suggestions for Authors

The article can be interesting for the enological community, studying the impact of berry and cluster thinning on the quality of Monastrell wines produced without sulfites, after three months and five years of storage.

Tilte: I think the fact that the wine comes from organic viticulture is undervalued. It should appear in the title "e.g....Monastrell organic wines"

Abstract.

Lines 18-19. Please reformulate “while also”, and “key aromatic compounds such as ethyl acetate and ethanol”. should be written "key volatile compounds" or replace ethanol with another aromatic compound (ethanol is an alcohol).

Introduction

The introduction presents the importance of aroma compounds and the concept of wine quality. the Introduction could be improved by adding information on the general volatile profile of the wine and how it changes, data on the Monastrell variety and its importance in the respective wine-growing area/region.

Line 73-74 please correct to “dimethyl dicarbonate (DMDC)”

Line 95 reference required.

M&M

Line 117 - please provide also the BBCH phenological stage code.

Lines 115-119 Please provide more details about the thinning of the grains and the shortening of the branches. Was it done on the same day, what tools were used (scissors, knife, blade or freehand)?

What was done with the berries and grapes harvested green (were collected and composted or thrown away?, is it possible to use them as a high-acidity wine for blending or may have another use)

Line 131 what temperature?

2.2. In my opinion, the fact that you did not control the alcoholic fermentation by inoculating with the same yeast may be a weak point of your experiment. Depending on the yeast that managed to develop in each fermentation variant, the aromatic profile and general physico-chemical features of wines may differ significantly.

Please specify if maceration was done and for how long. It should also be mentioned that “no other treatment was applied to the experimental wines”.

 

Results

Table 1. the standard deviation (±) must be presented in the table for each characteristic.

Applies to all tables.

Changes in the chromatic parameters would also have been of interest.

The discussion section is simply presented. Exploratory data analysis (principal component analysis, for grouping compounds or samples) is practically missing.

Conclusions. For such a "bold" conclusion, multi-year studies are needed, perhaps on several varieties, as well as stricter control of experimental parameters (maceration, alcoholic and malolactic fermentations).

The references are all mentioned in the text; most of them are older but relevant to the topic.

Author Response

Dear Reviewer,
Thank you very much for the work you did reviewing this work. Your suggestions have significantly improved the manuscript.
Below, we respond to your requests. You can find the changes made to the document in blue. You can see that we have addressed all your requests.

 

The article can be interesting for the enological community, studying the impact of berry and cluster thinning on the quality of Monastrell wines produced without sulfites, after three months and five years of storage.

Response: Thank you very much for your valuable comment. We're sure that, thanks to your extensive review, the article has improved significantly, making it easier to read and improving the quality of the information it contains.

 

Title: I think the fact that wine comes from organic viticulture is undervalued. It should appear in the title "e.g....Monastrell organic wines"

Response: Reviewer is right. Authors have modified title to include this practice.

 

Abstract:

Lines 18-19. Please reformulate “while also”, and “key aromatic compounds such as ethyl acetate and ethanol”. should be written "key volatile compounds" or replace ethanol with another aromatic compound (ethanol is an alcohol).

Response: Done as suggested.

 

Introduction:

The introduction presents the importance of aroma compounds and the concept of wine quality. the Introduction could be improved by adding information on the general volatile profile of the wine and how it changes, data on the Monastrell variety and its importance in the respective wine-growing area/region.

We've rewritten part of the introduction to incorporate the reviewer's apt suggestion. Please review the section to see the changes (especially lines 104-110).

 

Line 73-74 please correct to “dimethyl dicarbonate (DMDC)”

Response: Done as suggested. Please, see line 82-83.

 

M&M:

Line 117 - please provide also the BBCH phenological stage code.

Lines 115-119 Please provide more details about the thinning of the grains and the shortening of the branches. Was it done on the same day, what tools were used (scissors, knife, blade or freehand)?

Response: All the information required has been included into the same paragraph. Please, see lines 133-138.

 

What was done with the berries and grapes harvested green (were collected and composted or thrown away?, is it possible to use them as a high-acidity wine for blending or may have another use)

Response: Nowadays, in this experiment, It is virtually impossible to utilize berries from cluster thinning, as their quality and maturity are insufficient for vinification. In contrast, whole clusters removed during thinning could potentially be used, but the cost of harvesting and processing them would likely exceed the value of the resulting product. An alternative approach would be to delay cluster thinning, allowing the grapes to reach an alcohol potential of 10–11%, which could make them suitable for producing a base wine for sparkling wine or for acidifying other wines. This possibility could be explored in future experimental trials.

 

Line 131 At what temperature?

Response: During pressing, wine musts typically reach temperatures between 26°C and 28°C. Maintaining this thermal range is critical, as lower temperatures can impede the completion of alcoholic fermentation and inhibit the onset of malolactic fermentation, both essential processes for wine stability and sensory development. The process was carried out within the winery, utilizing the facility’s controlled temperature system to ensure optimal conditions for fermentation.

 

In my opinion, the fact that you did not control the alcoholic fermentation by inoculating with the same yeast may be a weak point of your experiment. Depending on the yeast that managed to develop in each fermentation variant, the aromatic profile and general physico-chemical features of wines may differ significantly.

The wine was fermented with wild yeast. Our experiments are always conducted using wild yeast. All treatments were carried out in the same vineyard plot under identical conditions, so the yeast population should be consistent across samples. That said, we agree with your point: if selected yeast strains had been used, we could be 100% certain that this part of the process was identical. However, such yeasts are not used in this winegrowing region.

 

Please specify if maceration was done and for how long. It should also be mentioned that “no other treatment was applied to the experimental wines”.

Done as suggested. We have added the following text to section 2.2 Winemaking: The wines were produced under identical conditions and using the same fermentation protocol and temperature (12 days at 26 ± 2 ºC). Please, see lines 149-150.

 

Results

Table 1. The standard deviation (±) must be presented in the table for each characteristic. Applies to all tables.

Response: In our humble opinion, the tables in the article are very large and contain a lot of information. Adding the standard deviation would make it difficult to read, as we would have to reduce the size significantly to fit all the information. Since the tables already show an ANOVA and a Tukey's multiple range test, the authors believe that, for the purpose of the study, which is to determine whether or not there are differences, these analyses capture these differences more accurately and reliably than the standard deviation.

 

Changes in the chromatic parameters would also have been of interest.

Response: Reviewer is fully right. It would have been interesting to monitor color changes through colorimetric analysis. However, we reserved all samples for sensory evaluation and ultimately focused the study on sensory perception, which led us to discard this measurement. In retrospect, we agree with your observation it was a mistake not to assess color using spectrocolorimetry, as it could have helped us better understand the perceived changes.

 

The discussion section is simply presented. Exploratory data analysis (principal component analysis, for grouping compounds or samples) is practically missing.

Response: This experiment shows results from two sampling periods, each analyzing three factors. We believe these data are insufficient to perform a principal components analysis that would summarize the results with statistical certainty, given the small number of factors. This test would only slightly help summarize the results but would not contribute anything new. For this reason, the authors believe it would be inappropriate to perform it.

 

Conclusions. For such a "bold" conclusion, multi-year studies are needed, perhaps on several varieties, as well as stricter control of experimental parameters (maceration, alcoholic and malolactic fermentations).

Response: The reviewer is right. The conclusions were left very open. We've rewritten the section, emphasizing that the results were obtained using Monastrell grapes and under the conditions studied.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

This study provides important evidence for organic winemaking and is worthy of publication.

Reviewer 2 Report

Comments and Suggestions for Authors

The requested changes have been made. As a suggestion, in the Conclusions section, please use the standard phrase "Further studies are necessary in order to..... (for lines 408-411).