v3.26.1
Cover - shares
6 Months Ended
Jun. 30, 2026
Aug. 13, 2026
Cover [Abstract]    
Entity Registrant Name BIRCHTECH CORP.  
Entity Central Index Key 0000728385  
Document Type 10-Q  
Amendment Flag false  
Current Fiscal Year End Date --12-31  
Entity Small Business true  
Entity Shell Company false  
Entity Emerging Growth Company false  
Entity Current Reporting Status Yes  
Document Period End Date Jun. 30, 2026  
Entity Filer Category Non-accelerated Filer  
Document Fiscal Period Focus Q2  
Document Fiscal Year Focus 2026  
Entity Common Stock Shares Outstanding   26,305,966
Document Quarterly Report true  
Document Transition Report false  
Entity File Number 000-33067  
Entity Incorporation State Country Code DE  
Entity Tax Identification Number 87-0398271  
Entity Address Address Line 1 1810 Jester Drive  
Entity Address City Or Town Corsicana  
Entity Address State Or Province TX  
Entity Address Postal Zip Code 75109  
City Area Code 614  
Local Phone Number 505-6115  
Security 12b Title Common Stock, par value $0.001  
Trading Symbol BCHT  
Security Exchange Name NYSE  
Entity Interactive Data Current Yes