I have just had some nasty black paint sand blasted off my 500 year old oak beams. They are now a nice light colour - what do I put on them to retain the light colour rather than making them too dark again.
The best finish I've used in terms of not darkening the wood is Osmo Top Oil, which is designed for treating wooden worktops. Of course, there is some darkening effect, but less than with many oil / wax products. Brushes on easily, and dries to a dead matt finish.
I have just used oak beams to create a curved wall , i used Linseed oil it gives a lovely light slightly golden colour. Several coats are required. I got the idea of Grand designs , when a architect used it to protect the whole of his wooden house.
Beeswax and turps,
Teak oil and turps,
Boiled linseed oil and turps,
Take your choice, but please not Danish oil.
Perhaps you should try all three on some offcuts and see which you like best.
Try to limit the use of sand blasting and historic fabric, if they were 500 year old beams sensitively stripped they could have shown a 500 year old decorative paint scheme upon them.