Pale ale of a sort one tucked into on Friday? (9)

'friday?' is the definition.
I know nothing about this answer so I can't tell whether it can be defined by this definition.

'pale ale of a sort one tucked into' is the wordplay.
'pale' becomes 'white' (pale in colour).
'ale of a sort' becomes 'bss' (I can't explain this - if you can you should believe this answer much more).
'one' becomes 'a' (a thing is one thing).
'tucked into' means one lot of letters goes inside another (I've seen this in other clues).
'bss' going around 'a' is 'bass'.
'white'+'bass'='WHITEBASS'

'on' acts as a link.

Can you help me to learn more?