Slow or stuck fermentation?

[NathanYearout]

Hello, this is my first time going for a pilsner and I've never done a cool fermentation before in a fridge.
Chose a popular Urquell clone on Brewfather and made the wort like usual and nearly everything went according to plan, it took a a while to chill the wort but nothing major. Hit starting gravity and everything was looking good.
I pitched one package of WY2007, it said to use one pack in 5 gallons of wort but I think it might be an underpitch still, we had a little over five gallons and I think I'd need a bit more.
It's been 3.5 days of fermenting at 51° and although I saw the airlock bubble once or twice it's incredibly slow and my tilt hydrometer has showed it staying at 1.067 without changing. I'm aware lagers are bottom fermenting though, could my tilt just not be showing the correct gravity because it floats? The homebrew shop near me doesn't open till Wednesday so I can't get more of that exact yeast. What should I try next? Wait it out or go into resuscitation mode?

 

[hottpeper13]

I've always thought that the lager yeast packs should have twice the amount since the ale and lager say one is enough for 5 gal when it's barely enough for an ale. Always ,always make a starter of some kind when using liquid yeast.
for now if you see a krausen ring of any kind I would give it a gentle swirl and see if the air lok blows. I think 51* is good.

 

[jdauria]

One pack of yeast in a lager is no way enough even if it were a 1.050 beer, but at 1.067, you are severely underpitched and are experiencing lag time as the yeast tries to grow, but there is more sugar than the yeast can handle. Wyeast and White Labs are notorious for their packaging saying "1 pack for beer up to X gravity", but it's not really true.

Using Brewer's Friend yeast calculator, 5 gallon batch of 1.067 lager at the minimum lager pitch rate needs about 465 billion cells, a Wyeast Smack pack would have close to 100 billion depending on how fresh it was. So you only pitched at the max 25% of the needed yeast. Now 4-5 packs of yeast can get expensive, so this is where yeast starters for lagers can really help a lot. 2 packs of the yeast in a 2.4 liter starter would have given you a proper level of cells unless the yeast was real old.

I would say just get 2 packs of dry yeast, something like 34/70 and toss it in.

 

[Steveruch]

It's been 3.5 days of fermenting at 51° and although I saw the airlock bubble once or twice it's incredibly slow and my tilt hydrometer has showed it staying at 1.067 without changing. I'm aware lagers are bottom fermenting though, could my tilt just not be showing the correct gravity because it floats?

Fermentation takes place in the body of the wort so the answer to that is no.