Using a different "colder" yeast with a kit lager

[simonj12]

I'm contemplating starting my third brew to distract myself from tapping into the first batch which is barely a week into its conditioning or worse still diving into batch 2 which is only half way through primary fermentation :nono: I'm using the last bit of room temperature space for batch 2 so I'm limited to the fridge-like climate of the garage for batch 3's primary fermentation. I have a tin of Brewmaker Pilsner Lager (5 gallons). The instructions say 18-21C for primary, way above garage temp. So should I use saflager yeast instead of the kit yeast? If so what type? I hear s23 and w34/70 work well at lower temps. And how much? Also will this affect fermentation time and the gravity required before it goes into the barrel?
I thought lager was meant to be brewed at lower temperatures but the only lager kits I've seen say room temperature.

 

[Muddydisco]

The lager kits all say room temps as not all people will be able to keep the temps required for the Lager strain yeasts.

SAFLAGER W-34/70 DRY LAGER YEAST is a good starting point, pitch big if you can, I did 2 packets, but If you can pitch big, then start fermentation at the fermentation temperature. Mr Malty's pitching rates are a good place to start . . .but as the temperature drops then amounts to pitch increase dramatically.If pitching w34/70 into 25L of wort at 10C you'd would probably use 75g. . . . Pitching at 16C then 40g would be enough and pitching at 18-20C 20g is adequate.

If you don't want to pitch huge then you can pitch at 18-20C, and over the next 24hours gradually reduce the fermentation temperature down to the correct fermentation temp . . . you will need to do a Diacetyl rest at the end of fermentation (Raise temp to 18C for 36 Hours, then crash cool).

The Czech rule of thumb for fermentation and lagering is
One day of fermentation for every degree Plato (1 Plato = 4 gravity points)
One week of lagering (at close to 0C) for every degree Plato.

My ferment took 5 weeks

 

[simonj12]

Thanks for your advice. Without it I would have ended up with something weak and sickly sweet by the sounds of it. So I think I'll pitch high with w34/70 in the garage for the lager and I won't panic if it takes a while. Then I can keep the indoor space for another warmer brew.