First Lager - Slow Start

[HomeBrew Esquire]

Recipe: 5G all grain. 6lb 2-row, 3lb flaked rice, 1 oz hallertau. Omega yeast german lager I. Brew day went great. Mash temps were on point. OG 1.045.

I made a 1.2L starter. Stir plate. Set ambient temp to 60F. Pitched it after 24 hours.

Fermenter is set to 54F. Using a spike fermenter with a glycol chilling unit to control temp.

Used spikes O2 kit to force O2 into fermenter to oxygenate wort.

My yeast is admittedly old. Date on pack is May 21. So I’m using it approx 4 months later.

Have a hydrometer in the fermenter measuring gravity. Here are the results so far:

Day 1: 1.045
Day 2: 1.045
Day 3: 1.045
Day 4: 1.044
Day 5: 1.043
Day 6: 1.041

I’ve never brewed a lager before and I’ve never used oldish yeast. My ales usually hit FG within a 3-4 days. This seems awfully slow. Let it ride? Do something to fix?

Any advice is appreciated!

Thank you!

 

[VikeMan]

I think you underpitched, and would expect a slowish start.

For 5 gallons of of 1.045 wort, beginning with a 4 month old pack of Omega (200B cells when fresh) lager yeast, BrewCipher would recommend a 2.6 quart stirred starter.

Lagers need higher pitch rates than ales, in part because of the lower fermentation temps.

That said, I wouldn't expect this fermentation to really get "stuck." Have you measured gravity with a regular hydrometer?

 

[HomeBrew Esquire]

Thinking the same! I haven’t measured with a regular one, just using my tilt hydrometer. I can definitely use a regular one.

 

[user 341102]

+1 for underpitching. But, you have movement on the gravity, so it will likely ferment out

 

[HomeBrew Esquire]

I appreciate the responses!

Here is an update on the gravity movement:

Day 1: 1.045
Day 2: 1.045
Day 3: 1.045
Day 4: 1.044
Day 5: 1.043
Day 6: 1.041
Day 7: 1.038
Day 8: 1.035
Day 9: 1.032

Temp still floating between 53-54F

It’s moving VERY slowly. As a side, PSI is showing at 5 in my closed fermenter.

At this rate, if it doesn’t get stuck, it will take quite some time to reach FG!

 

[VikeMan]

It’s moving VERY slowly. As a side, PSI is showing at 5 in my closed fermenter.

You could speed it up a little if you reduced the pressure, assuming you're using an adjustable spunding valve.