The problem you have by adding grains to kits that are already made up of that grain or similar grans is you throw the balance out or completly screw up the profile as pointed out by josh.
Personally when i did kits/extract + steeped grains i would always start with a bog standard light coloured kit. A Bitter, Draught, Lager, Pilsner, Pale ale Etc and work it up from there. The benifit of doing this is YOU build the grain flavour profile (ignoring the base malt) yourself and dont rely on whats been crammed into the tin. You can pretty much add the equivilant weights of specialty grain which is usually added to an all grain batch. This on its own will improve your beer 10 fold w/respect to the malt flavour profile.
Another benifit of doing this is you can closer copy peoples AG recipes that are known winners by only having to sub out the base malt w/ a kit or extract.
I just liked the idea of being able to build my own kit/extract beer from the ground up.
Below is my sweet stouts specialty grain addditions that got 3rd @ Stout extravaganza lastyear if you want to take this approach as noted above. I wouldnt recommend adding these to a stout kit however. Unless you want a RIS/Export stout flavour profile
0.40 kg Roasted Barley (Joe White) (413.0 SRM) Grain 7.2 %
0.25 kg Crystal, Dark (Joe White) (86.7 SRM) Grain 4.5 %
0.20 kg Carafa Special III (Weyermann) (470.0 SRM) Grain 3.6 %
0.20 kg Caramalt (Joe White) (17.3 SRM) Grain 3.6 %
0.50 kg Milk Sugar (Lactose) (0.0 SRM) Sugar 9.0 %
Cheers! :icon_cheers:
