How did this turn out? Was 7%CaraBoho on point? she a dark one!
Brewing one of these today with this recipe (6 gallons):
Czech Yourself; Wreck Yourself
49% Viking Pils
31.5% Bohemian Dark Malt
7% Carafa Special II (at sparge)
2% Melanoidin Malt
.5 oz Sterling 8.6%AA FWH (90 mins)
.75 oz Sterling 8.6%AA 30 mins
154F 60 min mash, batch sparge. Balanced Chloride/Sulfate ratio with just enough CaCl2 and gypsum added to RO to get 40 PPM of Calcium.
MJ Bohemian Lager Yeast
Shooting for 1.055, though most I had in Prague were assuredly 1.050 or under (12º).
It's been a while now, but I recall the efficiency was higher than expected (1.058) and it was slightly maltier than I wanted. If I brewed it again, I would probably drop the melanoidin and carared, as I don't know they added anything. It tasted more like getting a dark lager from an American craft brewery than the real deal in a Prague tavern -- which my previous version nailed pretty perfectly. I think the key to the balance of this style is that it is not too big, not too malty and not too roasty. There is a prominent caramel element, but since it is sufficiently dry, that element should not make the beer cloying or "portery."
It's a balance as a homebrewer who brews for himself and his wife primarily, as to how close to attempt to approximate classic styles. On one hand, my wife generally wants stronger, drier beers (dark and balanced or pale and hoppy) and I generally want smaller beers of a wider variety. Often that means I end up brewing bigger versions of classic styles, like a 1.060 "pilsner" or a 6.5% ABV "Belgian Single." Essentially, I tend to err on the side of too big and I think that is the wrong way to do this style of beer.
Of the major famous ones, I have to say that I preferred Kozel Cerny (where my avatar comes from) over U Fleku. But there were lots of different versions ranging from very dry and clean to more malty and robust. They were usually pretty small beers, though (10-12 degrees P). I am not convinced that Saaz is strictly necessary, as it seemed to me that not every brewery used Saaz in Czechia since several who did seemed to advertise "Zatec" prominently. It's conjecture, but I think Saaz is really expensive and sorta eaten up by the wealthiest breweries the way Amarillo and Simcoe were in the US a few years back.
FWIW, U Fleku tasted small and caramelly with very little roast. I couldn't have told you what hops were used or the hop schedule, and I assumed it was only hopped once. My mouth would have guessed it was 1.044 down to 1.010 and probably 25 IBUs. It was nearly black, but barely roasty at all (despite very dark foam). AI suspect it was even smaller than that and that the high amount of caramel malt tricks the palate into thinking it is a bigger beer.
If trying to do this style right, consider brewing one under 1.050. I believe a lot of the concern over the high percentage of cara malt used is because people are imagining that at a different scale. Of course, for competition, bigger often wins, but then maybe "more authentic" isn't really the point at that level.
Another point I want to make is that these aren't really "red beers," they are "nearly black beers." In the glass they look black in Prague (albeit using dimpled .5L mugs most of the time). Czech breweries often have a separate "red beer" that is like ~14 SRM in addition to their pilsner and "cerny" (dark beer). I would really start around 20 SRM for a Czech Dark Lager, personally, and I think ~30 SRM is probably pretty common.