Lager fermentation problems

[visser Junior Member Find all posts View Profile Close visser]

I made a Vienna lager over the weekend and pitched a Saflager W-34/70 two liter starter on Sunday.

I put the carbouy in my fermentation chamber at 10 °C, but there are still no signs of fermentation.

Any suggestions what I should do now?

Should I raise the temperature to about 12 °C or take it out completely to get fermentation starting?

[Brennen Senior Member Find all posts View Profile Close Brennen]

You may have underpitched with the Saflager W-34/70 yeast. At temperatures below 12°C you should increase pitching rate (straight from http://www.fermentis.com/wp-content/...SFG_W34pdf.pdf).
I'll give it some time to populate the wort. If you are still worried, I'd repitch another 2L. But this will only be a hassle if you need to go and buy more yeast, rather leave it and let the yeast populate.
My suggestions:
For a 5 galUS batch: 2 packs or 4 l starter (rather use 2 packs to get 4 l starter)
For a 10 galUS batch: 4 packs and a huge starter

Your lager fermentation process will only take a lot longer with the underpitched batch.

[Brennen Senior Member Find all posts View Profile Close Brennen]

PS. The suggestions are based on lager fermentation. Ale yeast pitching requirements are less than that of lagers.

[SimonB Administrator Find all posts View Profile Close SimonB]

10 degrees is way too low to get that fermentation going nicely IMO. I normally start that yeast about 18 degrees, and then as soon as there is sign of activity it goes down to 12 degrees.

Also are you sure the carboy bung is properly sealed?

[visser Junior Member Find all posts View Profile Close visser]

10 degrees is way too low to get that fermentation going nicely IMO. I normally start that yeast about 18 degrees, and then as soon as there is sign of activity it goes down to 12 degrees.

Also are you sure the carboy bung is properly sealed?

Yes. I am sure the bung is properly sealed.

The problem is, I will only be back home on Saturday.

Will it be safe to wait till Saturday to add more yeast or raise the temperature, or should I rather give instructions now to switch off the freezer and let the temperature rise slowly on its own?

[Brennen Senior Member Find all posts View Profile Close Brennen]

It'll be easier to give instruction to switch the freezer off. But home brewing is all about learning.
If it was me, I'll leave it be and see what happens. Then next time I will manage appropriately.
But, I will suggest that next time you use double the starter size (with double the yeast count).