Assuming the Traditional Dark DME and LME have the same grain bill, composition for Traditional Dark LME is currently in the product information PDF: “a blend of 54% Bonlander® Munich Malt 10L, 30% Base malt, 13% Caramel Malt 60L, 3% Black Malt, and water”.
I just brewed with only Briess Traditional Dark LME, going for a Munich Dunkel. It isn’t ready yet, but I drank the gravity sample when I bottled it. Obviously too soon for a final judgement, but it seemed to be about like Modelo Negra, which is a Munich Dunkel as I understand it.
I went ahead and did a batch with 100% Briess Traditional Dark DME. Currently fermenting like crazy with some Lallemand Voss. I’ll report back. Getting some interesting banana aroma from the Voss
At day 10 in the keg, it’s a nice dark ale … somewhere between a brown ale and a porter to my palate. Mouthfeel is a little thin but the head is dense & creamy.
The final beer didn’t taste like Modelo Negra - it has some roasty flavor. For some reason I didn’t pick it up in the gravity sample. Maybe because attenuation was low - 1.016 FG. I usually get much better attenuation with S-189.
It’s allowable by BJCP (“Light to moderate roasted malt flavors can give a bitter chocolate palate that is never burnt.”) and present in the US versions I’ve had, but, yes, the one actual German example I’ve had was pretty devoid of roast character.