Select All Records From Table That Do Not Exist In Secondary Table
Using NOT EXISTS

Select DISTINCT
    bm.Location
    ,bm.[Beer (Upcoming Menu)]
FROM 
    ___SampleRequired bm
WHERE NOT EXISTS 
   (SELECT 1 
    FROM ___Sample td 
    WHERE LTRIM(RTRIM(bm.[Beer (Upcoming Menu)])) = LTRIM(RTRIM(td.Beer_name)))
AND bm.Type LIKE '%Mandate%'
AND bm.Location = 'StapleChase'


Also, Max Vernon has a nice answer comparing LEFT JOIN vs NOT EXIST It's also more common to see this in the wild versus the LEFT JOIN method where you also need to add table.key IS NULL in the WHERE clause. i.e td.Beer_name IS NULL

And, Martin Smith comparing NOT IN vs NOT EXIST.