-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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<SEC-DOCUMENT>0001140361-09-027393.txt : 20091124
<SEC-HEADER>0001140361-09-027393.hdr.sgml : 20091124
<ACCEPTANCE-DATETIME>20091124163102
ACCESSION NUMBER:		0001140361-09-027393
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20091123
FILED AS OF DATE:		20091124
DATE AS OF CHANGE:		20091124

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			KOCH C JAMES
		CENTRAL INDEX KEY:			0001008079

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-14092
		FILM NUMBER:		091205158

	MAIL ADDRESS:	
		STREET 1:		C/O THE BOSTON BEER COMPANY
		STREET 2:		75 ARLINGTON ST
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02116

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			BOSTON BEER CO INC
		CENTRAL INDEX KEY:			0000949870
		STANDARD INDUSTRIAL CLASSIFICATION:	MALT BEVERAGES [2082]
		IRS NUMBER:				043284048
		STATE OF INCORPORATION:			MA
		FISCAL YEAR END:			1226

	BUSINESS ADDRESS:	
		STREET 1:		ONE DESIGN CENTER PLACE
		STREET 2:		SUITE 850
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02210
		BUSINESS PHONE:		617-368-5061

	MAIL ADDRESS:	
		STREET 1:		ONE DESIGN CENTER PLACE
		STREET 2:		SUITE 850
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02210
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2009-11-23</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000949870</issuerCik>
        <issuerName>BOSTON BEER CO INC</issuerName>
        <issuerTradingSymbol>SAM</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001008079</rptOwnerCik>
            <rptOwnerName>KOCH C JAMES</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O THE BOSTON BEER COMPANY</rptOwnerStreet1>
            <rptOwnerStreet2>ONE DESIGN CENTER PLACE, SUITE 850</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02210</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chairman</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2009-11-23</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>G</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2400</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>388382</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2009-11-23</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>G</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>960</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>28102</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By trust</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">This transaction represents gifts by the Reporting Person to various trusts for the benefit of his children, two of whom share the Reporting Person's household.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Kathleen H. Wade under POA for the benefit of C. James Koch</signatureName>
        <signatureDate>2009-11-24</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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