First Lager - probably beginner mistake

[pvanessen]

Hey guys,

I started with DME, then went all-grain. Moved from cooler mash tun up to a grainfather. Did a Kölsch and an IPA in the GF. Came out well.

Then, I did my first lager. With the experience above, I am pretty sure I didn't do anything stupid until into the carboy.

Not sure if I am not patient enough or if I seriously underpitched the W34/70 (1 pkg only b/c the guy in the homebrew store said so. Made no starter b/c I was unaware that lagers need it).

Original Gravity:13.10 °P, 1.053
Measured Gravity after 11 days at 12C/54F: 5.58 °P, 1.022

It still bubbles every 2-3 seconds. But shouldn't it be closer to 1.011 by now?

So, here are my questions:
1. If I underpitched, is there anything I can/should do after 11 days into the primary? If yes, what?
2. Should I get it out of the carboy soon and do secondary until it reaches 1.011? Or transfer into keg and cool now and lager it for 3-4 weeks?

The sample tastes okay. No major off-flavors as far as I am concerned.

Thanks for your suggestions.
-Phil

 

[Gavin C]

Yes you under pitched

No there is nothing to do at this stage.

Let it finish. It's not at terminal gravity and still fermenting . The yeast doesn't know it was supposed to be finished by day 11. Sounds like things are chugging along nicely despite the under-pitch.

When it's 1-2 plato above terminal gravity you could raise the temperature to ~68F to ensure complete attenuation and carry out a diacetyl rest.

I usually do this when krausen has dropped and the SG is at my desired 1-2 plato above expected FG. In your example I would be looking for about 1.015-1.020 but it doesn't need to be that precise.

Once that's done and FG is reached and is stable, keg it up carb it and lager it at as close to 32F as you want. I lager at ~35F as that is what my keezer is set at.

NB: With the lagering phase there may still be a tiny bit more of a drop in gravity ~1-2% which is likely negligible if you have done everything else right.

But overall sounds like things are on track. Just a bit more time and things are likely to finish out nicely. Dry yeast-packs have a very wide range of estimated cell-counts so you may well not have under-pitched by much. The lager's flavor may indicate differently.

I would not transfer to a secondary. Despite the labels in the profile below I never use one. The timings listed are only estimates from the planning phase. Actual changes to temp is dictated by gravity readings and visual clues.

This is an example of the fermentation profile I use for my lagers with WLP833

Hope it turns out well for you.

 

[kh54s10]

I agree with Gavin C. Lager yeast do their thing a lot slower than Ale yeasts do. It probably didn't start as soon as it would have if more yeast was pitched so a couple of days longer than normal the at the cold temperatures it will be a few days longer than with Ales. Do the diacetyl rest suggested then lager at about 32-35 for a couple weeks to a month or so.

 

[pvanessen]

Thanks guys. Will let it bubble for another day or two, then do a diacetyl rest for two days. Then transfer into a keg.

I guess my question is, if the yeast will keep fermenting even if I cool it down to 35F?!

Can I still expect the FG to go down to 1.011 (or so) ?

 

[Gavin C]

Let it ferment to completion at the diacetyl rest temperature once you decide to ramp it up. Once you know it's completed fermenting, crash cool, (+/- finings), keg and carb. Lager in the keg.

I think based on what you're describing it will likely get down to ~1.011