Hello to everyone I'm new here and doesn't got the best english, already saying sorry for my errors.

Coming back to what I'm curious about, I got a stif levain got from my work and now I'm making artisan bread at home but I store my levain in the fridge and some times some breads doesn't come with any sour, it rise preatty well.
I feed him just 1 time per week almost, some times more whem I'm going to make bread.

cold fermetation for levain make it less sour?