Investigating the Influence of Vessel Shape on Spontaneous Fermentation in Winemaking

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

In the article “Unveiling the Potential of Prehistoric Winemaking: The Effect  of Vessel Shape on the Performance of Spontaneous Fermentation Phenomena” authors aim to investigate the impact of to discover whether the shape of the vessels could influence the performance of spontaneous fermentation.

The topic in interesting, and the manuscript has enough quality to be published. But after the reading, this reviewer considers that two items should be deepen:

1) The authors used glass containers to perform their experiments. Fermentations in the AShSh and BB cultures were carried out in ceramic containers, with more porous surfaces. Authors should include a discussion of this in section 4 (Limitations).

2)      An interesting question is whether there is archaeological record of the microorganism present in spontaneous fermentations in the AShSh and BB cultures was Saccharomyces cerevisiae or whether there were other non-saccharomyces yeasts. If this record exists, it would be interesting to include it in the introduction. 

Author Response

1. The authors used glass containers to perform their experiments. Fermentations in the AShSh and BB cultures were carried out in ceramic containers, with more porous surfaces. Authors should include a discussion of this in section 4 (Limitations).

The justification is related to the minimization of the influencing factors other than the vessel shape. Glass containers were sterilized and so the effect of any microbiota residing within the clay was avoided. Text added in section 4 (Limitations), lines 709-713.

2. An interesting question is whether there is archaeological record of the microorganism present in spontaneous fermentations in the AShSh and BB cultures was Saccharomyces cerevisiae or whether there were other non-Saccharomyces yeasts. If this record exists, it would be interesting to include it in the introduction.

Unfortunately, there are no records of the microorganism present in spontaneous fermentations in the AShSh and BB cultures. As far as we know, the oldest evidence of wine S. cerevisiae recovered from clay vessels was reported by Cavalieri et al. (2003) in Egypt at least 3150 BC. This comment was added in lines 103-104.

Cavalieri, D., McGovern, P. E., Hartl, D. L., Mortimer, R., & Polsinelli, M. (2003). Evidence for S. cerevisiae fermentation in ancient wine. Journal of Molecular Evolution, 57, S226-S232.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript entitled Unveiling the Potential of Prehistoric Winemaking: The Effect of Vessel Shape on the Performance of Spontaneous Fermentation Phenomena, presents information related to the development of fermentation process using different bioreactors geometries. The authors evaluated different oenological parameters. However, the manuscript has several issues that the authors must attend to. Below are the comments.

-The title of the manuscript must be improved. Did the authors really unveil the prehistoric winemaking?

-The abstract does not summarize the methods and results obtained.

-Lines 48-80. What is the rationale for describing all the history of vessels used for the production of wine? What was the effect of vessels on wine's characteristics or production? Are there updated information related to the use of different vessel's shapes in the production of wine?

-Introduction section. Since the manuscript is an original article, the authors must provide a solid background of previous works related to the effect of vessel/bioreactor shape on the production of wine. The information presented does not justify the development of the work.

-Line 134. Provide details for local companies.

-Section 2.2. What was the rationale for using cylindrical/conical/spherical vessels? This information must be depicted in introduction section. What is the background related to the shape of bioreactors on the production of wine or fermented beverages?

-Section 2.4. Provide details of the methods used for the quantification of phenol index and anthocyanin content. Didi the authors used standard solutions for the quantification? Didi authors carried out colorimetric reactions? 

-Section 2.5. Provide details related to the elution method used for GC-FID.

- Section 2.6. Deposit DNA sequences of microbial isolates into a database such as GenBank and provide the accession numbers. 

Comments on the Quality of English Language

No comments.

Author Response

1. The title of the manuscript must be improved. Did the authors really unveil prehistoric winemaking?

The title was too optimistic. Indeed, there is much to be unveiled to understand pre-historic winemaking. Our work is a contribution to the debate based on our [winemaking and microbial background]. We have changed the title accordingly with two examples:

1. In the Mists of Prehistoric Winemaking: The Effect of Vessel Shapes on the Performance of Spontaneous Fermentation Phenomena.
2. Prehistoric Winemaking: The Effect of Vessel Shapes on the Performance of Spontaneous Fermentation Phenomena.

Both options are correct, depending on the reviewer’s opinion.

2. The abstract does not summarize the methods and results obtained.

Changes were made in the Abstract to meet this question, by adding method information and the most relevant results.

3. Lines 48-80. What is the rationale for describing all the history of vessels used for the production of wine? What was the effect of vessels on wine's characteristics or production? Is there updated information related to the use of different vessel shapes in the production of wine?

The mention of the history of the vessels was shortened since this was not the core of the article. There are mentions to the influence of the shape on the quality of wines in other contexts that were added to the text. As far as we are aware this is the first article that tests the effect of shape on spontaneous fermentations. We improved the text to explain the rationale of our hypothesis.

4. Introduction section. Since the manuscript is an original article, the authors must provide a solid background of previous works related to the effect of vessel/bioreactor shape on the production of wine. The information presented does not justify the development of the work.

We added a few information related to the shape of the vessel in lines 123-145.

5. Line 134. Provide details for local companies.

Lines 162-164. Added accordingly.

Line 822. Also, in the Acknowledgments part.

6. Section 2.2. What was the rationale for using cylindrical/conical/spherical vessels? This information must be depicted in the introduction section. What is the background related to the shape of bioreactors in the production of wine or fermented beverages?

This issue is described in lines 65-66.

7. Section 2.4. Provide details of the methods used for the quantification of phenol index and anthocyanin content. Did the authors use standard solutions for the quantification? Did authors carry out colorimetric reactions?

The methods are more thoroughly described along with references in lines 217-230.

8. Section 2.5. Provide details related to the elution method used for GC-FID.

The method was described more thoroughly in lines 235-240.

9. Section 2.6. Deposit DNA sequences of microbial isolates into a database such as GenBank and provide the accession numbers.

We are waiting for the deposit DNA sequences. I will immediately give you an update once the results are ready. Thank you for your patience and understanding. 

Author Response File: Author Response.pdf