Will my jailbreak lose after downgrade?

1.Im planning to downgrade my Iphone 3gs to IOS 5.1.1 to IOS 4.1… Do i need to jailbreak again after downgrading it? Or Will i lose my jailbreak after downgrading?

2. After downgrading to IOS 4.1 when i jailbreak using redsn0w is jailbreaking using redsnow tethered or untethered?

1. After downgrading, you will lose all user data, and the jailbreak and its tweaks will also be lost. So after the jailbreak, you will need to rejailbreak.

2. The jailbreak will be UNTETHERED. You can use the latest version of redsn0w, or use greenpoison too. But this site i found will tell you which tool you need and which version (and download link is there too) after you enter your model and iOS version. It says for an iPhone 3gs on ios 4.1, to use Greenpois0n RC6.1 or redsn0w 0.9.6b2. But here is the link for the site. Just skip baseband, as unlock doesn't matter (put in iphone, 3gs, and ios 4.1) :)
http://www.jailbreak-me.info/jailbreak-wizard.html

Hope this was a perfect answer.
My channel:
www.youtube.com/tylerschoulte