I haven't pored over every post here so I may be duplicating some info.
For all intents and purposes, the only thing that separates ales and lagers stylistically is flavor and, to some extent clarity. Brewing process is essentially the same but fermentation regimen is usually somewhat different. Precise temp control is the key difference. If you have that, you can produce a nice lager.
Technically speaking, the difference is in the yeast used is a different species and acts at a different temperature range. All yeasts will metabolize sugars and produce alcohol over a range from as low as 50 to as high as 90. They have a distinct preference for a particular portion of that range in terms of the esters and phenols they produce (or don't produce). Low temp fermentation with most yeasts, ale or lager, produces diacetyl and sulfur compounds. You don't want either of those. The sulfur will dissipate (more on that later) the diacetyl has to be metabolized by active yeast late in the fermentation.
Kegging is easier but you can absolutely bottle-condition lagers.
Here's a procedure that should work for you...
- Mash and boil as usual with a grist of Pilsner malt - Vienna or Munich malt is not out of place as an addition or a large portion of the fermentables.
A step-temp mash will help express malty character (I'm not sure you mentioned, but I'm assuming that you're brewing all-grain). A long rest at 148F and a longer one at 158F with a water addition will get you a lot of highly fermentable sugars plus some dextrins for body. A mash-out and slow sparge will help as well.
- One hour boil with bittering hops and a small late addition of hops for flavor -nobel hops usually preferred. Definitely use Whirl Floc or similar.
- Cool wort to 65F. Add oxygen by any means available. Sloshing/rocking will help a lot but actual O2 through a carbonating stone is best.
- Pitch a forgiving lager yeast at double the amount that you usually use for ales. Dry yeasts like Fermentis S-23 or 34-70 are excellent.
- Hold the temp very steady at 65 degrees through a few days or up to a week of fermentation until you're confident that about 80 percent of attenuation has occurred but definitely not to full attenuation.
- Raise temp to 69 F, maybe 70F and allow to ferment for several days until all activity is stopped and the yeast has started to drop on it's own. This stage could go on for a week or 10 days with no ill effect. You will smell sulfur...don't worry
-When you're very confident of full attenuation ( sulfur smell should be diminished) , bring the temperature down hard and fast to as near 32F as you can. Lager yeasts do not flocculate very well and the cold temps are necessary to clear the beer. This is the lagering phase. There's a lot of confusion, but "lager" simply refers to storage, which traditionally happened in very cold caves. There's no further significant fermentation at this stage. That can be confirmed by precise gravity readings. After a period of at least a week but not more than 4 weeks or so, you should have very, very clear beer. If you keg, you can transfer, force carb and enjoy.
- Bottling a lager is the same as an ale but you have to consider that most of the yeast may be gone so it's not a terrible idea to add a small quantity of yeast back in when the cleared beer is transferred to a bottling vessel. If you're transferring directly from fermenter to bottles, each bottle can be inoculated with a drop of hydrated dry yeast along with the priming sugar. Carbonate as usual at high fermentation temp - 72F should do. Allow plenty of time for the carbonation to happen.
- Since refermentation has occurred, the beer has become slightly cloudy with yeast. A second lagering period is necessary. Stored at near freezing for 2 to 4 weeks, the bottles should be crystal clear.
All that being said, you can just brew
like simple ale with light malt for grist and simple hops for bittering, ferment with Fermentis S-04 at 65F, bottle condition as usual and allow bottles to sit for 3 -4 weeks in the fridge. The beer will be clear and clean and very reminiscent of a lager at that point.
