Lager Fermentation

[Dave V]

hi Everyone - it's a sunny bank holiday here in the UK, hope everyone is staying safe and well wherever you are. I brewed a lager for the first time last week (Kingpin lager by Brewdog if you are interested, KINGPIN - BrewDog Recipes ) and pitched the yeast (White Labs WLP 840 Lager Yeast) at 10 degrees C (50 F) on Friday evening. It's now Monday afternoon and there's no krausnering at all - there appears to be a sediment at the bottom of the bucket and the gravity has dropped a few points (OG was 1.042ish, now about 1.038). Can I get some advice on what lager fermentation is supposed to look like and how long I need to ferment it in primary? All my ales have been foaming within 36 hours but I've read that lagers don't foam as much - I'd been planning on reracking after a week or so but I feel I may need to leave it longer. Any advice/pointers much appreciated! Cheers Dave

 

[Ralphie0523]

This does seem pretty sluggish. A few ideas:

1.Did you pitch enough yeast? Lagers tend to need a higher pitch rate. There are calculators that can help you figure this out.

2. Can you increase temp a few degrees?

3. Was your mash temp and length ok?

4. Did your recipe have plenty of base malt?

5. Are all temps confirmed with another thermometer?

More info would help narrow it down.

 

[Dave V]

This does seem pretty sluggish. A few ideas:

1.Did you pitch enough yeast? Lagers tend to need a higher pitch rate. There are calculators that can help you figure this out.

2. Can you increase temp a few degrees?

3. Was your mash temp and length ok?

4. Did your recipe have plenty of base malt?

5. Are all temps confirmed with another thermometer?

More info would help narrow it down.

Hi Ralphie,

Thanks for the reply. In answer to your questions...

1. I used one pack of WLP 840 - I'd (naively I think!) assumed one pack would be enough. I've had a look at a couple of calcs like you said which suggest I need nearer to 3...I've ordered a couple online this morning but I think they'll be a few days before arriving. Any thoughts on whether this would cause problems? i.e. pitching more yeast some time later on?

2. I've turned the fridge off and opened the door - will see if this helps!

3. Yep - 75 mins, it was slightly too hot to start with but I cooled it down with ice

4. Yep, about 9lbs

5. I've got 2 x thermometer strips on the primary fermenter plus a sensor in the fridge that agree with each other

Thanks for the pointers, I'll keep you posted!

Dave

 

[Ralphie0523]

1. I would wait and see, but since you have a few days this may work itself out with (2)

2. Hopefully a few degrees warmer helps. If it takes off be prepared to cool down.

3.What was your mash temp? Did you confirm with a second thermometer?

Other potentials seem to have been eliminated from what I can tell here.

 

[Dave V]

1. I would wait and see, but since you have a few days this may work itself out with (2)

2. Hopefully a few degrees warmer helps. If it takes off be prepared to cool down.

3.What was your mash temp? Did you confirm with a second thermometer?

Other potentials seem to have been eliminated from what I can tell here.

Hi Ralphie - pleased to report a light krausnering is now visible! It got up to about 18 C with the fridge door open so I've now panicked and turned the fridge back on to get it back to 10C.

Mash temp was 65C (although it started off about 72 - strike water was too hot but cooled it down quite quickly).

The gravity is now at 1.033ish - I guess i'm used to ales that drop massively very quickly - is that a feature of lagers? they creep down slowly?

thanks again for advice!

Dave

 

[VikeMan]

The gravity is now at 1.033ish - I guess i'm used to ales that drop massively very quickly - is that a feature of lagers? they creep down slowly?

Lager fermentations are usually slower than ale fermentations, especially so if under pitched.

 

[Ralphie0523]

Hi Ralphie - pleased to report a light krausnering is now visible! It got up to about 18 C with the fridge door open so I've now panicked and turned the fridge back on to get it back to 10C.

Mash temp was 65C (although it started off about 72 - strike water was too hot but cooled it down quite quickly).

The gravity is now at 1.033ish - I guess i'm used to ales that drop massively very quickly - is that a feature of lagers? they creep down slowly?

thanks again for advice!

Dave

Sounds like you had an under pitch plus lower end of the temp scale. Hopefully things are rocking now. Lagers are generally slower as VikeMan says. However I would say the results you had were much more indicative of an under pitch.

A pitch of a proper amount of yeast that is in good health isn’t foolproof but prevents a lot of issues. Best of luck on the lager!

 

[waldoar15]

I use 940 usually instead of 840 and pitch it to a 2L starter. It's still going to be slow at 50* compared to ales. I just give them a few weeks and they always finish fine.