Somewhat inspired by the flavour Dean got out of his S-23 (it reminded me of anchor steam), I'm going to deliberately abuse the yeast for a steam beer. Don't have any Northern Brewer so I'm using Nugget instead. The recipe is incredibly simple.
11lbs 2-row
0.5lbs Cara-Munich 2
0.5lbs Carafoam
0.5oz Nugget 12% @ 60
0.5oz Nugget 12% @ 15
0.5oz Nugget 12% @ 0
Whirlfloc @ 0 (whirlpool before CFC)
4 gallons mash @ 148F, 4 gallons sparge @ 168F.
Safale S-23 - Ferment at 16C, leave at same temperature for a few weeks, cold crash, keg, serve.
The S-23 goes through a phase fermenting at 16C where it absolutely _reeks_ of rotten eggs - must be the DMS. I blamed it on our dog until I tracked it back to the source - stink bomb material for sure. Smelled fine when I took a wiff this morning, so I'm not concerned about any residual stank in the beer.
I was going to try an experimental warm brewed lager at 20C, but that might be way out of S-23's range. How are you controlling fermentation temp? I also heard the same thing about Kolsch yeast, they throw off a tonne of sulfur during primary fermentation and take an additional few weeks to clean themselfs up when brewing at higher temps. How long are you planning to primary?
Primary for a week or two after visible fermentation has stopped, transfer to secondary, lager for a month depending on how samples taste, carb, serve.
The packet lists up to 24C but lists 12-15 as optimal; this being a steam beer I've obviously overshot that. Temperature is just as-is within my brew-room, which I've seen floating between 15C and 17C (night/day) in the last couple of weeks - I figured I'd just let it roll on ambient and see what happens.