This tasting was organised by Boylen Publishing / Vinpac International and held at the Australian National Wine Centre on 22 January 2002.

Objective

To compare and contrast the attributes of 18 Riesling wines sealed with screwcaps and corks. Method

• 18 Riesling wines were assessed by a panel of 11 tasters.
• The panel was made up of winemakers (Tim James, Pam Dunsford, Oliver Crawford, Kerri Thompson, John Vickery, Peter Godden), winery technical staff (Russell Johnson, Martin Caloghiris), retail and wholesale wine trade members (Sarah Hutton, David Cole) and a consumer (Bill Hofmeyer).
• The tasting was planned and managed by Richard Gibson, ex General Manager - Technical Services of Southcorp Wines and now consulting to the industry through Scorpex Wine Services.
• Richard Gibson worked in consultation with Peter Godden (AWRI) and Russell Johnston (Beringer Blass) during the planning of the tasting.
• The wines were from the 1996 (1 wine), 1997 (1 wine), 1998 (2 wines), 1999 (3 wines), 2000 (4 wines) and 2001 (7 wines) vintages.
• 15 Australian wines (mainly Clare and Eden Valley) and 3 New Zealand wines were used in the tasting.
• 3 bottles of each wine were contributed by wineries.
• The three bottles of each wine were sealed with various combinations of screwcap or cork (ie 2 bottles with screwcap, 1 with cork/2 bottles with cork, 1 with screwcap/3 bottles with screwcap).
• All corks used in the cork sealed bottles were one piece natural cork closures. The length, grade and supplier of the corks varied.
• All screwcaps used on the screwcap sealed bottles contained a tin faced compressible wad.
• The bottles were received in good faith from wineries as consistent examples of the same wine, differing only in the closure used to seal the bottle. No information is available on filling, sealing and post-bottling storage conditions for the supplied bottles.
• Brackets of three glasses representing individual screwcap or cork sealed bottles of the 18 wines were presented to each taster under blind tasting conditions.
• The wines were presented to the panel as received. No pre-tasting culling of faulty bottles was carried out.
• Tasting samples for the bottles of one wine were duplicated during the tasting, meaning that each taster assessed 57 samples representing the 54 different bottles of wine.
• Each taster rated each glass on a scale from 0 (absent) to 9 (strongest imaginable) for the following characteristics:

• If a taint was found, the tasters were asked to identify it (if possible).
• Tasters were asked to make overall comments about each sample of wine.
• Tasters were asked to comment on each bracket of three wines.
• After the tasting, all members of the panel received a copy of the draft results for comment.
  Tasting Outcomes
  
  

  The following outcomes were derived from the panel's written comments, the post tasting discussion and a review of the numerical tasting data derived from taster ratings for the six listed attributes. Richard Gibson participated in the tasting, but his scores were not included in the tasting data for calculation of averages.

  • Aroma Intensity

    There was no consistent difference found by the panel in overall aroma intensity between cork and screwcap sealed bottles of the same wine.

  • Development

    Most of the screwcap sealed bottles of older wines showed attractive development with little oxidative influence. In contrast, many of the cork sealed bottles showed oxidative notes as well as developed fruit characteristics. The older screwcap bottles were not fresh young Rieslings 'locked in time' - they showed attractive fruit development on the nose and lively palates. In the brackets of older wines, the screwcap wines were generally preferred by the tasters. These conclusions are supported by the tasting data. There was little overall difference between the mean scores for fruit development between screwcap and cork sealed bottles.

  • Variation Between Bottles With The Same Seal

    Some variation was found between cork sealed bottles of the same wine, especially in the older brackets. The variation was principally due to the degree of oxidation and the presence of taints (see below). Three brackets contained more than one screwcap sealed bottle. In these brackets, the screwcap bottles were found to be quite consistent.

  • Reductive Notes

    In discussion after the tasting, the panel felt that screwcap sealed wines showed slightly more reductive/sulphidic notes than cork sealed wines. The tasting data, however, showed little difference in the overall average score for this character between the cork and screwcap sealed bottles.

  • Taint

    Three cork sealed bottles from the 32 bottles opened (9.4 per cent) were scored by the panel at an average for taint of 3 or above on the scale of 0 to 9. Tasters detecting taint in these bottles commented that the character was similar to that known to be induced by the presence of chloranisoles, especially TCA. No screw cap sealed bottle was scored by the panel at an average above 1 for taint.

  • Fruit Freshness

    The sensory characteristics of younger wines were found to show less difference with the different seals, but several 2001 wines showed retention of fresh Riesling aromatics under screwcap while cork sealed bottles of the same wines were showing more development.

  • Oxidation

    In the post-tasting discussion, the panel observed that cork sealed bottles tended to show more oxidation than the stelvin sealed equivalents. This observation was reinforced by the higher average oxidation score that the panel gave to the cork sealed bottles. 4 bottles of the 32 cork sealed bottles opened (12.5 per cent) were scored by the panel at an average for oxidation of 3 or above on the scale of 0-9. No screwcap sealed bottle was given an average score by the panel above 3.

  • Other Sensory Factors

    Wines generally lacking in fruit lift and freshness or showing strong non-fruit characters eg volatile acidity or botrytis appeared to be less influenced by the different seals. As one taster put it - 'good wines appear to be enhanced by the use of screwcap while poor wines do not show the same contrasts'.

  • Other Discussion

    Part of the post-tasting discussion covered technical factors other than the closures that panellists speculated may have contributed to or accentuated the contrasts found in this tasting. These included:

    • Dissolved oxygen levels in the wine and headspace volume/composition at bottling
    • Levels of antioxidants in the wines
    • Storage temperature and orientation of the bottles post-filling
    • Bottling date
    • Extent of retained sulphide or fermentation characters in the wine at bottling
    • Carbon dioxide content at bottling

    No data on these points is available from the wineries that supplied the wines, preventing comment on the influences that these factors may have had on the differences found in the tasting.

  Wine List
  
  

Aroma intensity Fruit freshness Fruit development

Oxidation Taint Reduced/sulphidic notes

Our thanks to Richard Gibson (rgibson@scorpex.net) of Scorpex Wine Services and Ian Walsh of Boylen Publishing for their kind permission to reproduce this report.

7 March 2002

Bracket	Vintage	Wine	Cork#1	Cork#2	Cork#3	Stel#1	Stel#2	Stel#3
1	1996	Henschke Julius Eden Valley Riesling	763	492		103
2	1997	Pewsey Vale Eden Valley Riesling	437	923		609
3	1998	Richmond Grove Barossa Riesling	892	604		289
4	1998	Richmond Grove Watervale Riesling	190	519		117
5	1999	Leasingham Clare Valley Bin 7 Riesling	776	824		299
6	1999	Richmond Grove Barossa Riesling	896	507		642
7	1999	Richmond Grove Watervale Riesling	194	732		876
8	2000	Knappstein Clare Valley Riesling	327	334		457
9	2000	The Wilson Vineyard Gallery Series Riesling	697	186		935
10	2000	Richmond Grove Limited Release Barossa Riesling		845		163	505
11	2000	Jim Barry Watervale Riesling	128	858		944
12	2000	Knappstein Clare Valley Riesling	958	438		176
13	2001	Skillogalee Clare Valley Riesling				976	703	431
14	2001	Petaluma Riesling	389	698		307
15	2001	Kim Crawford Marlborough Dry Riesling	524	224		109
16	2001	Henschke Julius Eden Valley Riesling	678			765	904
17	2001	Framingham Classic Riesling	455	356		551
18	2001	Wolf Blass Gold Label Eden Valley - Clare Valley Riesling	768	580		156
19	2001	Neudorf Moutere Riesling	696	347		458

Our thanks to Richard Gibson (rgibson@scorpex.net) of Scorpex Wine Services and Ian Walsh of Boylen Publishing for their kind permission to reproduce this report.

7 March 2002

Bracket	Vintage	Wine	Cork#1	Cork#2	Cork#3	Stel#1	Stel#2	Stel#3
1	1996	Henschke Julius Eden Valley Riesling	763	492		103
2	1997	Pewsey Vale Eden Valley Riesling	437	923		609
3	1998	Richmond Grove Barossa Riesling	892	604		289
4	1998	Richmond Grove Watervale Riesling	190	519		117
5	1999	Leasingham Clare Valley Bin 7 Riesling	776	824		299
6	1999	Richmond Grove Barossa Riesling	896	507		642
7	1999	Richmond Grove Watervale Riesling	194	732		876
8	2000	Knappstein Clare Valley Riesling	327	334		457
9	2000	The Wilson Vineyard Gallery Series Riesling	697	186		935
10	2000	Richmond Grove Limited Release Barossa Riesling		845		163	505
11	2000	Jim Barry Watervale Riesling	128	858		944
12	2000	Knappstein Clare Valley Riesling	958	438		176
13	2001	Skillogalee Clare Valley Riesling				976	703	431
14	2001	Petaluma Riesling	389	698		307
15	2001	Kim Crawford Marlborough Dry Riesling	524	224		109
16	2001	Henschke Julius Eden Valley Riesling	678			765	904
17	2001	Framingham Classic Riesling	455	356		551
18	2001	Wolf Blass Gold Label Eden Valley - Clare Valley Riesling	768	580		156
19	2001	Neudorf Moutere Riesling	696	347		458

• 18 Riesling wines were assessed by a panel of 11 tasters.
• The panel was made up of winemakers (Tim James, Pam Dunsford, Oliver Crawford, Kerri Thompson, John Vickery, Peter Godden), winery technical staff (Russell Johnson, Martin Caloghiris), retail and wholesale wine trade members (Sarah Hutton, David Cole) and a consumer (Bill Hofmeyer).
• The tasting was planned and managed by Richard Gibson, ex General Manager - Technical Services of Southcorp Wines and now consulting to the industry through Scorpex Wine Services.
• Richard Gibson worked in consultation with Peter Godden (AWRI) and Russell Johnston (Beringer Blass) during the planning of the tasting.
• The wines were from the 1996 (1 wine), 1997 (1 wine), 1998 (2 wines), 1999 (3 wines), 2000 (4 wines) and 2001 (7 wines) vintages.
• 15 Australian wines (mainly Clare and Eden Valley) and 3 New Zealand wines were used in the tasting.
• 3 bottles of each wine were contributed by wineries.
• The three bottles of each wine were sealed with various combinations of screwcap or cork (ie 2 bottles with screwcap, 1 with cork/2 bottles with cork, 1 with screwcap/3 bottles with screwcap).
• All corks used in the cork sealed bottles were one piece natural cork closures. The length, grade and supplier of the corks varied.
• All screwcaps used on the screwcap sealed bottles contained a tin faced compressible wad.
• The bottles were received in good faith from wineries as consistent examples of the same wine, differing only in the closure used to seal the bottle. No information is available on filling, sealing and post-bottling storage conditions for the supplied bottles.
• Brackets of three glasses representing individual screwcap or cork sealed bottles of the 18 wines were presented to each taster under blind tasting conditions.
• The wines were presented to the panel as received. No pre-tasting culling of faulty bottles was carried out.
• Tasting samples for the bottles of one wine were duplicated during the tasting, meaning that each taster assessed 57 samples representing the 54 different bottles of wine.
• Each taster rated each glass on a scale from 0 (absent) to 9 (strongest imaginable) for the following characteristics:

• If a taint was found, the tasters were asked to identify it (if possible).
• Tasters were asked to make overall comments about each sample of wine.
• Tasters were asked to comment on each bracket of three wines.
• After the tasting, all members of the panel received a copy of the draft results for comment.
  Tasting Outcomes
  
  

  The following outcomes were derived from the panel's written comments, the post tasting discussion and a review of the numerical tasting data derived from taster ratings for the six listed attributes. Richard Gibson participated in the tasting, but his scores were not included in the tasting data for calculation of averages.

  • Aroma Intensity

    There was no consistent difference found by the panel in overall aroma intensity between cork and screwcap sealed bottles of the same wine.

  • Development

    Most of the screwcap sealed bottles of older wines showed attractive development with little oxidative influence. In contrast, many of the cork sealed bottles showed oxidative notes as well as developed fruit characteristics. The older screwcap bottles were not fresh young Rieslings 'locked in time' - they showed attractive fruit development on the nose and lively palates. In the brackets of older wines, the screwcap wines were generally preferred by the tasters. These conclusions are supported by the tasting data. There was little overall difference between the mean scores for fruit development between screwcap and cork sealed bottles.

  • Variation Between Bottles With The Same Seal

    Some variation was found between cork sealed bottles of the same wine, especially in the older brackets. The variation was principally due to the degree of oxidation and the presence of taints (see below). Three brackets contained more than one screwcap sealed bottle. In these brackets, the screwcap bottles were found to be quite consistent.

  • Reductive Notes

    In discussion after the tasting, the panel felt that screwcap sealed wines showed slightly more reductive/sulphidic notes than cork sealed wines. The tasting data, however, showed little difference in the overall average score for this character between the cork and screwcap sealed bottles.

  • Taint

    Three cork sealed bottles from the 32 bottles opened (9.4 per cent) were scored by the panel at an average for taint of 3 or above on the scale of 0 to 9. Tasters detecting taint in these bottles commented that the character was similar to that known to be induced by the presence of chloranisoles, especially TCA. No screw cap sealed bottle was scored by the panel at an average above 1 for taint.

  • Fruit Freshness

    The sensory characteristics of younger wines were found to show less difference with the different seals, but several 2001 wines showed retention of fresh Riesling aromatics under screwcap while cork sealed bottles of the same wines were showing more development.

  • Oxidation

    In the post-tasting discussion, the panel observed that cork sealed bottles tended to show more oxidation than the stelvin sealed equivalents. This observation was reinforced by the higher average oxidation score that the panel gave to the cork sealed bottles. 4 bottles of the 32 cork sealed bottles opened (12.5 per cent) were scored by the panel at an average for oxidation of 3 or above on the scale of 0-9. No screwcap sealed bottle was given an average score by the panel above 3.

  • Other Sensory Factors

    Wines generally lacking in fruit lift and freshness or showing strong non-fruit characters eg volatile acidity or botrytis appeared to be less influenced by the different seals. As one taster put it - 'good wines appear to be enhanced by the use of screwcap while poor wines do not show the same contrasts'.

  • Other Discussion

    Part of the post-tasting discussion covered technical factors other than the closures that panellists speculated may have contributed to or accentuated the contrasts found in this tasting. These included:

    • Dissolved oxygen levels in the wine and headspace volume/composition at bottling
    • Levels of antioxidants in the wines
    • Storage temperature and orientation of the bottles post-filling
    • Bottling date
    • Extent of retained sulphide or fermentation characters in the wine at bottling
    • Carbon dioxide content at bottling

    No data on these points is available from the wineries that supplied the wines, preventing comment on the influences that these factors may have had on the differences found in the tasting.

  Wine List
  
  

Aroma intensity Fruit freshness Fruit development

Oxidation Taint Reduced/sulphidic notes

Our thanks to Richard Gibson (rgibson@scorpex.net) of Scorpex Wine Services and Ian Walsh of Boylen Publishing for their kind permission to reproduce this report.

7 March 2002

Bracket	Vintage	Wine	Cork#1	Cork#2	Cork#3	Stel#1	Stel#2	Stel#3
1	1996	Henschke Julius Eden Valley Riesling	763	492		103
2	1997	Pewsey Vale Eden Valley Riesling	437	923		609
3	1998	Richmond Grove Barossa Riesling	892	604		289
4	1998	Richmond Grove Watervale Riesling	190	519		117
5	1999	Leasingham Clare Valley Bin 7 Riesling	776	824		299
6	1999	Richmond Grove Barossa Riesling	896	507		642
7	1999	Richmond Grove Watervale Riesling	194	732		876
8	2000	Knappstein Clare Valley Riesling	327	334		457
9	2000	The Wilson Vineyard Gallery Series Riesling	697	186		935
10	2000	Richmond Grove Limited Release Barossa Riesling		845		163	505
11	2000	Jim Barry Watervale Riesling	128	858		944
12	2000	Knappstein Clare Valley Riesling	958	438		176
13	2001	Skillogalee Clare Valley Riesling				976	703	431
14	2001	Petaluma Riesling	389	698		307
15	2001	Kim Crawford Marlborough Dry Riesling	524	224		109
16	2001	Henschke Julius Eden Valley Riesling	678			765	904
17	2001	Framingham Classic Riesling	455	356		551
18	2001	Wolf Blass Gold Label Eden Valley - Clare Valley Riesling	768	580		156
19	2001	Neudorf Moutere Riesling	696	347		458

Our thanks to Richard Gibson (rgibson@scorpex.net) of Scorpex Wine Services and Ian Walsh of Boylen Publishing for their kind permission to reproduce this report.

7 March 2002

Bracket	Vintage	Wine	Cork#1	Cork#2	Cork#3	Stel#1	Stel#2	Stel#3
1	1996	Henschke Julius Eden Valley Riesling	763	492		103
2	1997	Pewsey Vale Eden Valley Riesling	437	923		609
3	1998	Richmond Grove Barossa Riesling	892	604		289
4	1998	Richmond Grove Watervale Riesling	190	519		117
5	1999	Leasingham Clare Valley Bin 7 Riesling	776	824		299
6	1999	Richmond Grove Barossa Riesling	896	507		642
7	1999	Richmond Grove Watervale Riesling	194	732		876
8	2000	Knappstein Clare Valley Riesling	327	334		457
9	2000	The Wilson Vineyard Gallery Series Riesling	697	186		935
10	2000	Richmond Grove Limited Release Barossa Riesling		845		163	505
11	2000	Jim Barry Watervale Riesling	128	858		944
12	2000	Knappstein Clare Valley Riesling	958	438		176
13	2001	Skillogalee Clare Valley Riesling				976	703	431
14	2001	Petaluma Riesling	389	698		307
15	2001	Kim Crawford Marlborough Dry Riesling	524	224		109
16	2001	Henschke Julius Eden Valley Riesling	678			765	904
17	2001	Framingham Classic Riesling	455	356		551
18	2001	Wolf Blass Gold Label Eden Valley - Clare Valley Riesling	768	580		156
19	2001	Neudorf Moutere Riesling	696	347		458