Fermenting in sanke with stem still in?

Going to do this next batch. Do you just pull out the gas check valve and plug the out port? once the coupler is engaged air is allowed out the gas in right? Going to put a cobra tap filled with sani on out port btw.

I have some reservations about this.
What you're describing seems like it could work, but the gap in the gas-in opening (your gas-out in this setup) is small, if that gets plugged, or the tap gets closed, this thing will go critical very fast.
The thought of an exploding sanke keg scares me, and there's really no reason to go this way. I'm sure you know about the kits that exist to ferment in a sanke, and orange carboy caps work fine to cover the top if you don't want that expense.

Good luck with however you go, and stay safe.

Pretty sure people do it. I've been using the carboy cap but using a coupler will make transfer much easier.

Why not just pull the stem and eliminate any real chance of having a problem?

I have 5 15.5 sankes that I ferment in and just pulled the stems on all of them. Size 11 drilled stopper and a regular airlock. Works like a charm.

You can transfer under pressure with one of those orange carboy caps. It even holds the racking cane very well. Just don't push with more then 5lbs of gas or it will blow the cap off.

Those work OK but the stainless caps from brewers hardware are sooooo much better. I have one and love it

BTW I don't think it's a great idea to leave the stem in. It might work but the orange cap is really cheap and works well.

What I would suggest is to just place the stem in the keg without the spiral ring for the active fermentation and cover w/ foil or cling wrap as the o-ring will seal with the weight of the stem hanging in the keg and actually makes a check valve of sorts. Once fermentation is complete, install the spiral ring and transfer away. I was offered a 1/2 keg at a local brewery that was somehow overpressurised as the bottom was stretched out like a balloon due to I'm guessing overpressure...wow?

Sometimes I secondary in a sanke and will just insert the stem and put a paper towel w/ star san over the neck of the keg...it's sealed pretty darn well.

OH edit, you want to do a blow-off...I would not try a blow off through the small opening in a sanke coupler....JMO.

I know all the options. I have sanke couplers and all sorts of attachment for them, so why not? Only disadvantage to the brew'shardware fermenter kit is that my racking cane/stem will not be adjustable. I've fermented in cornys with a qd connected to the gas in without clogging. Just pulled my stem out and connected a coupler and paid attention to how far it pushes the stem down to allow for air. It's much more space then is allowed out of a poppet valve. Also not scared of pressure build up with a cobra tap connected to liquid out. If something clogs the gas passage, the cobra tap will be forced open way before any dangerous pressures occur. Eventually want to connect a spunding valve, which I already used with my corny ferments, and ferment under pressure. Going to connect blowoff for first couple ferments with coupler.
Has anyone fermented with the stem in and had any problems?