Originally Posted by brian320fo
Needless to say it was a difficult transfer because it was highly carbonated due to the fact the CO2 had not been escaping.
Clearly you used a lager (pilsner) yeast strain (which is a good thing when making real lagers). Lager yeast strains develop a lot of sulfur (especially the first few days of fermentation), it will smell really bad rotting eggs. Most frequent mistake when making a lager (and I think this is what happened here) is cold crashing or contitionning the beer too soon once the fermentation appears to have stopped. I made quite a lot of lagers and the "trick" is to raise the temperature to ale temp fermentation for few days to a week only once the FG is attained (that is usually after 3 weeks but it depends at wich temp your were fermenting). Because even if FG is attained and you see no fermentation activity, the yeasts continue to eat up sulfur that was created at the beginning of fermentation (that is why you need some yeast in your secondary too). If you try to conditioned the beer too soon after reaching FG, the sulfur will stay in the beer. And it really will smell and taste bad. The fact that you had CO2 in your carboy says that fermentation was not even finished. And the fact that the airlock was plugged up prevented Co2 and sulfur to escape also. No wonder you got a lot of sulfur. Another good trick (the best I think) is to taste the beer before you try to conditioned it. That way you make sure that sulfur is gone.
Now, can you save your batch? There is 2 ways you can try to save your batch (in fact 3 ways but one, given the probable size of your batch, is more expensive than starting new again). You can try to flush the sulfur by adding co2 then flush it then put some back then flushing again and repeat that until sulfur is gone (but sometimes it doesn't work). The second method is to add some sugar and repitch with new yeast (that will eventually eat the sulfur). But my experience says that it is much more work than starting over a new batch. If you follow these fermentation temp, you will not miss. 1st week around 10°C, second week raise to 12°, third week raise to 14°, fourth week raise to 18°C and even if fermentation appears to have stopped, wait until your beer does not taste sulfur before conditionning it. Because you used lager yeasts at low temp the first 3 weeks you beer will have the character of a real lager not of an ale.