Vanilla Irish stout

Firstly I searched around and couldn't quite find what I was looking for so sorry for the 1000th vanilla bean thread.
I brewed a brewers best Irish stout extract on friday, April 30 and i was thinking of adding some vanilla. My qeuestions are... How many beans should I use (5 gallon batch), will an Irish stout taste good with vanilla and the big one; I don't have a secondary so when should I add the beans and for how long should I let it set?

Vanilla beans are incredibly potent. I would suggest one and then monitor closely the next couple days. My experience comes from brewing a Chocolate stout. To turn down the bitter from the chocolate I was advised to add some vanilla bean. Beer turned out a little more vanilla than chocolate but it wasn't bad.

The taste of the vanilla will grow, like many other additions, for however long the beer sits on it. I think I let the stout sit for 7 days maybe longer and there was definitely a nice vanilla scent. No chocolate though

Cheers

Here's the thing, the beans I got were from my mom and they expired a year and a half ago they smell and look fine so I'm gonna use them. I just figure they may have lost some flavor so should I use one or two.

I've used vanilla beans often in my Imperial Stout, This is the way I do it:

The day I brew I cut 2 beans in slices and put them in a glass bottle with a shot of Bourbon (you can use vodka).

Every day I shake the bottle vigurously.

After two weeks of fermentation I open the lid of the bucket and simpli pour the content of the bottle inside.

Let it sit for two more weeks (since I use the "Four Weeks in Primary" metod.

I hope it's usefull fot your stout.