Using 3 year old unopened Wood Stain

Hi

I live in Winnipeg, Manitoba and about 4 years ago after researching your site, I bought a 5 gallon pail of Armstrong Clark Wood Stain - Sierra Redwood colour to stain my PT wood deck. I ran into some health issues and am only now ready to get to work! I cleaned and pressure washed the deck, sanded off the fuzzy bits but am wondering if the stain will still be good after all that time? It's still in the sealed original container and has been kept inside during that time. 

Thanks for your advice in advance

Steve