An easy festbier recipe:
50% pilsner malt, 5% Weyerman caramunich III, 5% Weyerman carared, 35% light munich malt, 3% acid malt, 2% Weyerman cara-aroma (added at mash out to reduce 'roasted' flavors). First-wort hop with 22 IBUs from noble hops-preferably Tettnang or Hallertau varieties. Single infusion mash at 152-usually 30 minutes or less, boil 90 minutes, O.G. 1.055
pH is very important for this style of beer, both in the mash, and sparge water. You will want a residual alkalinity as close to 0 as possible, and this can be easily achieved with gypsum and calcium chloride. The high enzyme content from the pils malt will reduce the mash time. This combined with the lower pH in the mash will leech fewer tannins from the barley hulls. Cara-aroma contains no enzyme, so adding it at mash out will extract color and aroma while minimizing roasted notes that would be out of character. First-wort hopping will enhance the 'noble hop' character.
Most german lager strains are acceptable as long as they accentuate the malt character. My fermentation profile may seem odd at first, but it has really worked well for me. I pitch at 45 F for the first 72 hours (after first signs of fermentation). Then raise to 48 for another 72 hours. after that, I raise the temp 1 degree per day until 58 F. Usually it only needs 1-2 days at 58 to finish fermentation. When fermentation has finished, I rack to the secondary vessel, and begin lowering the temperature over 72 hours. In the first 24 hours I drop it to 50 F, in the second, 40 F, the third day I drop it to the final lagering temperature of 28-29 F. Lager for 3-5 weeks depending on gravity of the beer. For high gravity lagers, I double the fermentation times below 50 F.
Decoction mashes can be fun if you want to brew old-school, but are generally unnecessary with modern malts, unless you have unusually low enzyme content in your mash. Heffeweizens can benefit from a single or double decoction because of the lower enzyme wheat malt as well as the high protein/glucan content that makes sparging an all-day event.