Cover Page - shares	3 Months Ended
	Mar. 27, 2021	Apr. 16, 2021
Document Information [Line Items]
Document Transition Report	false
Document Quarterly Report	true
Document Type	10-Q
Document Period End Date	Mar. 27, 2021
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Registrant Name	THE BOSTON BEER COMPANY, INC.
Entity Interactive Data Current	Yes
Entity Shell Company	false
Entity Small Business	false
Entity Emerging Growth Company	false
Entity File Number	1-14092
Entity Incorporation, State or Country Code	MA
Entity Tax Identification Number	04-3284048
Entity Address, Address Line One	One Design Center Place, Suite 850
Entity Address, City or Town	Boston
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02210
City Area Code	617
Local Phone Number	368-5000
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Entity Central Index Key	0000949870
Current Fiscal Year End Date	--12-26
Trading Symbol	SAM
Security Exchange Name	NYSE
Title of 12(b) Security	Class A Common Stock
Common Class A
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		10,108,792
Common Class B
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		2,177,983