Lager fermentation

Hi Folks,
I have just made a Mexican Cervasa. Used American lager Yyeast 2035 pitched at 21C and allowed to begin fermentation (bubbles).
Transferred to the fridge where it is held at a constant 12C. How long should this be in the fridge at this temperature? There are no real signs of fermentation activity?
Thanks

Many years ago homebrewers were often told to start lager fermentation high, then cool to lager fermentation temps, usually specified as 50F. I tried that a few times and the fermentation always stopped for two or three days when I dropped the temp. Yeast cells seem to take offence to being chilled suddenly.

Contemporary guidance is:
Chill the wort into the 40s.
Oxygenate/aerate.
Pitch a large, healthy starter (use the pitch calculator in Beersmith to determine how large a starter you need).
Don't worry about over-pitching. Using half (or all) the slurry left from a previous batch works exceptionally well and saves money.
Set the fermenter temp (not the temp of the air in the fermentation chamber) between 50 and 55F.
Be patient.

Keep the beer in the fridge until at least two gravity reading, taken three days apart, are the same. Then, warm the beer five to ten degrees to ensure it has finished and to let it finish cleaning up the undesirable stuff the yeast created in their youthful exuberance. Be patient! Depending on airlock activity can result in bottle bombs and trips to the ER. Yes, I did. Yes, they exploded. Yes, I went to the ER and got two sutures in the back of my arm.

Thanks for that.
In short do you think I should simply leave the current batch (17L) sitting in the fridge at 12C (53.5 F)? It has been in there for 5 days now and for how long?

Greetings,

My experience had been that lagers tend to take weeks sometimes to fully ferment.  So I would agree with durrettd, when the SG readings are the same when taken twice with about two to three days in between readings, allow the beer to come to room temperature for a few days for the diacetyl rest, then rack to bottles or the secondary as required.

Thanks again,

I'll do what you suggest and see how it turns out. I dont mind waiting.
I'm beginning to think that this lager making may turn out to be more bother than it is worth.
I may stick to Ales in the future.

I wouldn't get discouraged. You know what they say - good things come to those who wait! Lagers offer a wonderful experience in the beer world, both in taste and in creating.  Yes, they can be a pain. But that pain goes away as soon as you pour your first glass.  By your 5th glass, you'll be planning another batch.

Thanks for that.
I had to smile reading your reply. I'm sure you are right, the problem is I am like Methuselah and can wait for ages, which is more than I can say for my friends. Bugger them I say I'm gonna go for it and they can have the IPA ;D