The phrase "although hitherto" is correct and usable in written English.
It can be used to introduce a contrast or exception regarding something that has been true up to the present moment.
Example: "Although hitherto we have seen little progress, we remain hopeful for future developments."
Alternatives: "even though until now" or "despite the fact that up to this point".
There has been constant criticism throughout his tenure that Cook does not appear to be the one with complete authority, although hitherto his record had been first-rate.
In reality, a significant (although hitherto unknown) amount is simply funds being routed via nostro bank accounts from the Middle East, which hosts over 2.5 million Filipinos.
In the case of apples, the popular belief is that apples ripen first at the stem end, although hitherto this has not been validated.
She had her cover, a typical American family clustered around their traditional — although hitherto unknown — Christmas tree.
Although hitherto virtually unpublicized outside academic circles, the program has now established "partnerships" with more than 90 American universities.
Although hitherto known larval Tabanomorpha are mainly predators, some larvae suck the body fluids of vertebrates such as anurans (Jackman et al., 1983).
Unfortunately, due to ice conditions and uncertain navigation, it was not possible to exactly confirm the locations of the holes, and nothing was found although hitherto-unknown depths were found at the locations that were consistent with Inuit testimony of the wreck.
The current coach, Huh Jung-moo, is an underwhelming choice in the eyes of many South Koreans, although a hitherto sceptical public were encouraged by a 2-0 defeat of Ivory Coast in March.
The orchestra played for other managements, and managed to survive, although the hitherto remunerative work for regional choral societies dwindled to almost nothing.
Hitherto, although there have been reports of troops moving northward and of concentrations of Black Shirts, no additional classes have been called up.
Although India has hitherto been one of Iran's main suppliers of refined gasoline and diesel, the difficulty in getting letters of credit recently forced Iran to find supplies through Singapore.
