kill lager yeast before pitching ale yeast?

So I've got a classic american pilsner that's been sitting for about 84 hours now with no signs of fermenting. No bubbles in the air lock, no krausen. It was aerated with an aeration stone, and I cold pitched (50 degrees) two packs of wyeast pilsen lager yeast. This morning I took a hydro reading. The reading said I had dropped .002. So I guess it has done something, but a lot less than I would hope after almost 4 days. This morning I gave it another 30 minutes of aeration and am warming it up from 50 to 60ish. If I don't see anything more happen soon I think I'm going to pitch a packet of S-05. This was a really awesome all-grain wort that I spent a lot of time on and I'd rather turn it into an ale than have it spoil by sitting around for a few more days.

My worry is that whatever remaining lager yeast there is will make some funky flavors at the ale temperature. Should I attempt to kill them off with some campden tablets before warming up and pitching the ale yeast?

Thanks for your ideas.

You under pitched without a starter, I expect it will eventually take off. I wouldn't be aerating and when it does start to go active a bit more I'd slowly ramp the temp back down. I wouldn't use an ale yeast at this point as you are going to have an issue with the lager yeast. More than likely you are going to need a long lagering period on this one.

Before you pitch us05 put the beer in a room temp for a day. If it doesn't work then pitch us05, but I wouldn' try to kill the lager yeast.

I agree with the others. I think just raising the temp a little will get them working and let them get off to a decent start as you drop temp slowly.

thanks for the replies everyone. Samc, are you thinking that the aeration was a bad idea because there would have already been some alcohol produced and therefore I may have caused some oxidization that will negatively affect the beer?

Aeration is bad after the first few hours (12 I've seen as the number), with certain exceptions with higher alcohol beers. I wouldn't worry about that at this point, focus more on bringing down the temps when things get going. My first few Lagers suffered from too little yeast and bad temperature control, they did improve with long lagering times but were never great beers. If you follow the process outlined in Brewing Classic Styles along with Mr Malty pitching rates you will have great Lagers.

An easy way to brew w lager yeast is to use Diacetyl Rests.
First, after pitching yeast keep the beer in ale temps untill you see some signs of activity (or 24 hours). This will insure a good start for the yeast.
Later, after the primary (~2 weeks) move the beer again to ale temps for ~24h. This will insure a low finish, so you won't get a over-sweet beer or even worst: bottle-bombs.

thanks for the ideas everyone. at this point it sounds like i've made a few mistakes with the under pitching and late aeration.

the beer is now at 60 and doesn't look any closer to doing anything. I still have my hydro sample from this morning in a test jar. It is probably at 68 and there isn't a sign of anything about to happen. No little co2 bubbles or anything. The surface looks as flat as a glass of water.

I'm starting to wonder about the viability of the yeast, which I had shipped last week when it was really cold around here (6-8 degrees).

If I don't see anything in another 24 hours I am wondering about leaving it at 58-60 degrees and pitching a packet of Notty. Hopefully at that temp the Notty can turn this stuff into beer and any existing lager yeast won't throw too many funky tastes.

I know everyone is advising me to wait for the lager yeast to start, but at what point would I just want to throw the Notty. We're going on 5 days now. Opinions?

Hey Alsace,

I am in the same boat with you right now man. 192 hours in and no fermenter activity. I took a sample of the wort and have had it at room temperature and it has just started going. I am hoping that the fermenter will follow suit shortly. I had the same thought of making it an ale, but like you, feared the nasty flavors of the lager yeast at ale temperature. Take a look at the thread I posted, it is almost identical to what you are going through. Maybe we will both see some significant changes in the next couple days.

Fermenter was bubbling away last night. Not sure what is going on, but you might not want to give up just yet. Best of luck man.