I use it all the time for my lagers and in a pinch, in my ales too as base malt. As far as "undermodified", read this as "less modified" than their 2-Row Brewers Malt. As a comparison, Briess's reports "Typical Analysis" for these 2 malts as follows;
Pilsen 2R Brewers
Extract FGDB 80.5 80.5
Extract CGDB 78.5 79.5
F/C 2 1
S/T 42 37
Alpha Amylase 45 50
DP 130 140
Color 1.0 1.8
Keep in mind this is typical analyses and not real analyses batch to batch. For all malt brewers like us homebrewers where the base malt is 50 -60 % or better of the mash bill, these 2 malts have sufficient modification for brewing. Note the low color on the Pilsen for nice light colored lagers.
Give it a try in your lighter colored beers!
Dr Malt
