<PAGE>

                                                                     EXHIBIT 4.6


                                                                [Execution Copy]

     SUPPLEMENTAL INDENTURE NO. 6 (this "Supplement"), dated as of August 21,
2001, is entered into by and among CONSTELLATION BRANDS, INC. (formerly known as
Canandaigua Brands, Inc.), a Delaware corporation (the "Company"), RAVENSWOOD
WINERY, INC., a California corporation and an indirect wholly-owned subsidiary
of the Company (the "New Guarantor"), and BNY MIDWEST TRUST COMPANY (successor
trustee to Harris Trust and Savings Bank and The Bank of New York, as
applicable), as trustee (the "Trustee").


                 RECITALS OF THE COMPANY AND THE NEW GUARANTOR

     WHEREAS, the Company, the Guarantors and the Trustee have executed and
delivered an Indenture, dated as of February 25, 1999 (the "Base Indenture");  a
Supplemental Indenture No. 1, dated as of February 25, 1999 with respect to the
issuance by the Company of its 8 1/2% Senior Subordinated Notes due 2009 in the
aggregate principal amount of $200,000,000 (the "First Supplemental Indenture");
a Supplemental Indenture No. 2 dated as of August 4, 1999 with respect to the
issuance by the Company of its 8 5/8% Senior Notes due 2006 in the aggregate
principal amount of $200,000,000 (the "Second Supplemental Indenture"); a
Supplemental Indenture No. 3 dated as of August 6, 1999 with respect to the
guarantee of the Indenture Obligations by new Subsidiaries of the Company (the
"Third Supplemental Indenture"); a Supplemental Indenture No. 4 dated as of May
15, 2000 with respect to the issuance by the Company of its 8 1/2% Series C
Senior Notes due 2009 in the aggregate principal amount of (Pounds)154,000,000
(the "Fourth Supplemental Indenture"); and a Supplemental Indenture No. 5 dated
as of September 14, 2000 providing for certain amendments to the Fourth
Supplemental Indenture (the "Fifth Supplemental Indenture" and together with the
Base Indenture, the First Supplemental Indenture, the Second Supplemental
Indenture, the Third Supplemental Indenture and the Fourth Supplemental
Indenture, collectively, the "Indenture");

     WHEREAS, the Guarantors guarantee, jointly and severally, the full and
punctual payment and performance when due of all Indenture Obligations;

     WHEREAS, pursuant to (i) Section 3.10 of the First Supplemental Indenture;
(ii) Section 3.9 of the Second Supplemental Indenture; and (iii) Section 4.15 of
the Fourth Supplemental Indenture, the New Guarantor is obligated to enter into
this Supplement thereby guaranteeing the punctual payment and performance when
due of all Indenture Obligations;

     WHEREAS, pursuant to (i) Section 11.1 of the First Supplemental Indenture;
(ii) Section 9.1 of the Second Supplemental Indenture; and (iii) Section 8.01 of
the Fourth Supplemental Indenture, the Company, the New Guarantor and the
Trustee may enter into this Supplement without the consent of any Holder;

     WHEREAS, the execution and delivery of this Supplement have been duly
authorized by a Board Resolution of the respective Boards of Directors of the
Company and the New Guarantor; and
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                                      -2-

     WHEREAS, all conditions and requirements necessary to make the Supplement
valid and binding upon the Company and the New Guarantor, and enforceable
against the Company and the New Guarantor in accordance with its terms, have
been performed and fulfilled.

     NOW, THEREFORE, in consideration of the above premises, each of the parties
hereto agrees, for the benefit of the others and for the equal and proportionate
benefit of the Holders of the Securities, as follows:


                                  ARTICLE ONE
                               THE NEW GUARANTEE

     Section 1.01.  For value received, the New Guarantor hereby absolutely,
unconditionally and irrevocably guarantees (the "New Guarantee"), jointly and
severally among itself and the Guarantors, to the Trustee and the Holders, as if
the New Guarantor was the principal debtor, the punctual payment and performance
when due of all Indenture Obligations (which for purposes of the New Guarantee
shall also be deemed to include all commissions, fees, charges, costs and other
expenses (including reasonable legal fees and disbursements of one counsel)
arising out of or incurred by the Trustee or the Holders in connection with the
enforcement of this New Guarantee).  The agreements made and obligations assumed
hereunder by the New Guarantor shall constitute and shall be deemed to
constitute a Guarantee under the Indenture and for all purposes of the
Indenture, and the New Guarantor shall be considered a Guarantor for all
purposes of the Indenture as if the New Guarantor was originally named therein
as a Guarantor.

     Section 1.02.  The New Guarantee shall be released upon the occurrence of
the events as provided in the Indenture.

     Section 1.03.  The New Guarantor hereby waives, and will not in any manner
whatsoever claim or take the benefit or advantage of, any rights of
reimbursement, indemnity or subrogation or any other rights against the Company
or any other Subsidiary as a result of any payment by the New Guarantor under
its Guarantee under the Indenture.


                                  ARTICLE TWO
                               SUCCESSOR TRUSTEE

     Section 2.01.  The Trustee hereby confirms that it is the successor in
interest to The Bank of New York as trustee under the Fifth Supplemental
Indenture, and has succeeded The Bank of New York as trustee pursuant to a
transaction contemplated by Section 11.8 of the Base Indenture.
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                                      -3-

                                 ARTICLE THREE
                                 MISCELLANEOUS

     Section 3.01.  Except as otherwise expressly provided or unless the context
otherwise requires, all terms used herein which are defined in the Indenture
shall have the meanings assigned to them in the Indenture.  Except as
supplemented hereby, the Indenture (including the Guarantees incorporated
therein) and the notes issued pursuant thereto are in all respects ratified and
confirmed and all the terms and provisions thereof shall remain in full force
and effect.

     Section 3.02.  This Supplement shall be effective as of the close of
business on July 2, 2001.

     Section 3.03.  The recitals contained herein shall be taken as the
statements of the Company and the New Guarantor, and the Trustee assumes no
responsibility for their correctness.  The Trustee makes no representations as
to the validity or sufficiency of this Supplement.

     Section 3.04.  This Supplement shall be governed by and construed in
accordance with the laws of the jurisdiction which governs the Indenture and its
construction.

     Section 3.05.  This Supplement may be executed in any number of
counterparts each of which shall be an original, but such counterparts shall
together constitute but one and the same instrument.
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                                      -4-


     IN WITNESS WHEREOF, the parties hereto have caused this Supplement to be
duly executed and attested all as of the day and year first above written.

                                    CONSTELLATION BRANDS, INC.


                                    By: /s/ Thomas S. Summer
                                        -------------------
                                      Name:   Thomas S. Summer
                                      Title:  Executive Vice President & Chief
                                              Financial Officer
Attest:


/s/ David S. Sorce
-----------------------
Title:

                                    RAVENSWOOD WINERY, INC.


                                    By: /s/ Thomas S. Summer
                                        --------------------
                                      Name:  Thomas S. Summer
                                      Title:  Vice President & Treasurer
Attest:


/s/ David S. Sorce
-----------------------
Title:

                                    BNY MIDWEST TRUST COMPANY

                                    By: /s/ J. Bartolini
                                       --------------------------
                                      Name: J. Bartolini
                                      Title: Vice President
Attest:


/s/ Signature illegible
-----------------------
Title: Assistant Secretary