Putting standard beer on nitro

[MatIPluto]

So I recently set my kegerator up for nitro mix with a stout faucet and all that. I’m looking to at some point put a sixtel of founders breakfast stout on the nitro tap. If I buy a standard sixtel meant to run off CO2, would I need to decarbonate the beer before hand? If so, does anyone have a good method & would that have any negative effect on the beer?

 

[Qhrumphf]

Yes, you need to decarb and yes, it'll negatively impact the beer.

If you drive off carb you'll be driving off volatiles (ie aroma) with it.

The simplest solution is to vent the pressure almost entirely off the keg (like to just a couple PSI), let it reestablish equilibrium, and repeat. If the keg is already cold, you're looking for barely any equilibrium pressure (like 1 PSI at 38F) for a good nitro pour.

If you can hook up a spunding valve, set it to the right pressure and walk away.

 

[odie]

you could just turn the CO2 down to a couple PSI and tap a few beers until the carbonation comes down into range and then switch to nitro...get to sample both ways.

 

[Vale71]

A spunding valve would be best as it would allow you to set pressure and forget about it for a few days. If you don't want to invest in one you'll have to repeatedly pull the PRV until enough CO2 has been vented. Problem is without a manometer there's really no way of telling when you've vented enough CO2, there's really no way to just eyeball it.
As with carbonation to de-carbonete as fast as possible the beer should be at room temp and not cooled.