I usually do ales without any problems. But this time, I brewed a light lager (75% 2-row + 25% flaked corn, 12 IBU hallertau at 60 minutes). Fermented at 50F for 3 weeks with WLP-940 Mexican lager, no starter 1 vial for 2 gallons of beer. It tasted really nice before bottling (I was planning to do the lagering in bottles). I did not add new yeast prior bottling.
After 1 week of bottle condition (at 66F), not a lot of carbonation, sulfur taste (the fermentation wasn't complete).
After 2 weeks in bottles (at 66F), good carbonation but a strange green/herbal taste at the end. Is it acetaldehyde?
I have never had this problem with my ales in 10 years. Is it specific to lager yeast?
For now, I stated the lagering phase with some bottles (35F) and the other bottles are kept at room temperature (66F).
Is it possible to do a good bottle carbonated lager?