... I think Manticle's insights and my high-gravity boil post decoction may be largely responsible for the flavour I get, although I still don't understand why floor malting creates the precursors all other things being equal.
Ok Nick .... since you asked so nicely, I would like to help you but you need to give up on the abuse and start to help us to help you. You claim that you know how to brew lagers, but I cannot see anywhere that you have actually described how you brew lagers !
As you say, the standard Weyermann pils malt gives you a good tasting beer, but you are unhappy with the result when using the premium pils. So far there has been information supplied about non-enzymatic browning, hetero-cyclic suphur compounds and reductones. I must admit that I have not read all of your posts here as I find your abusive, abrasive posts unpleasant, but I can say that I have no idea what your current brewing practices are and hence I too, find it difficult to suggest what you could change.
This all assumes that you want to change - you responded with a smiley-face when someone else suggested that one option was to just accept that this grain is not for you and stick with something that does work. Hopefully you won't start to underline me !
If you consult the spec sheets that Mark posted
previously, you can see that the Premium is less modified (Hartong index of 34-39) when compared to the standard Bohemian Pilsener malt (38-44 Hartong). The Hartong index represents the ratio of soluable nitrogen to total nitrogen in the malt, which gives an indication of how much protein has been broken down during malting. Mark has suggested that you look at your mashing schedule, but I am not sure if you read it as it wasn't underlined.
Avoiding oxidation of the mash by spashing and stiring is also critical.
One worthwhile avenue for you to explore would be to consider if this reduced level of soluable nitrogen has an effect on the Amino Acid level of the wort and if this could be influencing the Maillard pathways dominant. The maillard compounds are formed during malt kilning and mashing, but the boil is the final determinant of their character. George Fix discusses these compounds in Analysis of Brewing Techniques (Table 1.26 p53 Sulphur-Bearing Heterocyclic Compounds) and considers that 'extreme thermal loading of wort appears to be the most likely mechanism for their creation". The percentage evaporation loss is a very usefull control parameter. The optimum rate of around 10% is sufficient for extracting hop constituents and controlling DMS and is achieved by using a 90 minute boil.
FWIW my standard procedure is to ensure an extended dough-in so that the malt spends around 30 mins going from room temp to 50c and then jumps up to 65 (avoiding spending much time at 50 as this kills the head retention), 90 minute mash with 10% evaporation during a 90 minute boil and do not experiece the character that you complain about.
Before anyone can help you further you will need to tell us the specifics of your mashing and boiling procedures as I beleive that this is where the solution lies.
HTH,
David
