First-time lager yeast, possible mishaps

[Sisyphus]

Hello, I've often used this forum to read the various how-tos people have posted, but today I figured I needed to post a question for myself. Friday night was my first time brewing with a lager yeast (and admittedly my second brew ever), and the particular strain, the man at the brew shop told me, ferments at 50-55 degrees. I was supposed to have a small wine refrigerator that I could have set to 53 degrees exactly, but the damn thing decided not to work, so I had to improvise quickly with a refrigerator. The refrigerator, however, has a temperature knob; the second-hottest setting generally settles at 40-45 (maybe a little higher on a hot day), and the warmest generally settles around 60-65. Not knowing which notch to settle on, I let it go for about 24 hours on the 60-65 notch, then let it gradually walk down to 45-ish (for some reason it's 50 right now, but I'm sure it was cooler last night and yesterday).

When I checked the brew upon coming back from an unexpected trip (my friend and fellow brewer was the one to walk down the temperature; I'm only just now seeing this thing), and there's a krausen at the top, which to me signifies fermentation, but there's no apparent air activity coming out of the blowoff hose. Also, there's an alarming amount of sediment at the bottom, which I always thought in the previous ales I had brewed was the yeats that had settled once it died. My conjecture is that fermentation began at the higher temperature, but the colder one killed the yeast. Is this correct? I have some pictures for reference:

My appallingly low krausen level

Krausen close-up

That change of color at the bottom is the sediment. Is this dead yeast?

 

[wonderbread23]

Lager yeast is a bottom fermenter. They do their thing from the bottom if the vessel.

 

[Sisyphus]

Ah, you're right. I completely forgot about that!

Should I still be unconcerned about the low krausen and no bubbling after over 72 hours? Also, which temperature would be better, the 40-45 range or the 60-65 range?

 

[integrator]

I had no more than 1/2" of Krausen on my Helles. And I've yet to seen much bubbling but it finished. A hydrometer test will tell you more but it looks fine.

And if it's at 50, leave it there. Yeast likes to stay at a constant temp.

Next time, cool down to 45 or so, pitch, then walk it up to 50 and leave it there. If you underpitched, you could do a rest, or do one anyways to be safe.

 

[kgraber]

Looks like my lager I'm doing right now that has been sitting at 50 degrees. I think you are good to go. One thing I highly recommend for lagers is to get a Johnson Temp controller. I'm using one on my older fridge and have it set to 50. It's been great to be able to just set it and not worry about it.

 

[Sisyphus]

Also, in the settled yeast, there are small but deeply blue spots, almost purple. Is this normal?