In Germany where they follow the RHG, these sulfites need to come from the yeast because they're not allowed to add SMB. Hence the preference for lager strains which produce sulfur during the ferment. However, both Narziss and Kunze state that it's commonplace in other countries for breweries to add SMB or KMB at packaging to hit the 10 ppm mark. This is especially common in cask ales in the UK, where the maximum allowed limit as actually 30 ppm.
When I and others have measured commercial German lagers from the bottle with sulfite test strips, we've measured them to typically be around 10 ppm, and sometimes as high as 20 ppm. Of course, the strips aren't the most accurate thing in the world, but I think that it at least does demonstrate that yes, the commercial examples have in the neighborhood of 10 ppm and it's by design.
I have seen some people report problems with too much excess sulfur, especially with ale yeast. Lager yeast seem to be much more effective at consuming excess sulfite left over post boil. However, other people have used 100 mg/l SMB in a no-sparge mash with no problems at all. The simple fact is that every system and process is different, and some brewers tend to get a lot more oxygen pickup when they brew - this is what makes a "one size fits all" guideline so difficult and why low oxygen brewing is all about fine tuning your individual system through trial, error, and measurement.
I've mentioned before and still believe that the ultimate goal of anyone interested in getting serious about low oxygen brewing should be to tighten up the system as much as possible so that they can get away with as small of a dose of SMB as possible. If you are brewing no-sparge with a pseudo-closed system (i.e. floating caps on the wort in the mash and lauter tuns like I use in my system), have zero leaks whatsoever in your pump lines, dough in with no aeration, and do nothing else at all which introduces a significant amount of oxygen into the wort, then you should be able to get away with 30-40 mg/l SMB, maybe even less.
IMO the goal should boil down to this: Get cold, un-oxidized wort in the fermenter with ~10 ppm or less residual sulfite. Pitch your yeast, aerate, and ferment. From the end of fermentation onwards, do everything humanly possible to avoid the slightest bit of contact with air.Statistics: Posted by Techbrau — Sun Oct 09, 2016 10:55 pm
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