I recently bought a small book about Belgian ales from NB. So far it seems that Belgium, rather than Germany, is beer heaven. Oud Bruin, Dubbel, Tripel, Saison, and Trappist beers.
Next weekend I will start Dubbel Bruin, 6 gallons:
4 lb Vienna malt (Briess)
4 lb Munich malt (Briess)
4 lb pale 2-row (Rahr)
1 lb honey malt (Gambrinus)
1/2 lb CaraPils (Briess)
1/2 lb Special B (imported from Belgium)
SO 4 will give you an English, not a Belgian character. You need to choose a liquid Belgian strain if you really want to make a dubbel. I am not familiar with Apollo hops, but you should use something that resembles continental hops like Hallertau, Saaz, Styrian Goldings, or something similar. Dubbel is a more malt accentuated beer so you probably just want to add 20 IBU or so of bitterness. Oud Bruin is a sour beer so it will also need low hops if that is the style you are trying to brew. Good luck with your brew.
I would try Wyeast 3522 Belgian Ardennes. It’s a fantastic Belgian yeast and my go to for most Belgians I brew. For this style, I’d ferment on the cooler side. Somewhere in the low 60’s.
And I’d agree with the above statements about your hop additions. Apollo are a big citrusy american hop. You want a more earthy or spicy noble hop. Maybe 15-20 IBU at 60min and a small dose later on somewhere around 15-20min. Or even just a 60min addition.
Because of the yeast choice, and the unconventional late addition of 18% AA hops, you won’t have a “Belgian!” but I am intrigued. Plus the equal parts Vienna, Munich, 2-row, then 1/2 lb special b (skip the carpils w/ that much munich and special b) – I am trying to taste this in my mindmouth but I can’t get it. the grain bill is not unlike a marzen I made, minus the special b. But the late addition apollo throws off me off the trail. If I had more time I would brew up stuff like this. It sounds good. Take dobe’s advice and put it on belgian ardennes. cut the munich to 3lbs or cut the special b by half. You don’t want it to be too cloying. make sure your late add Apollos will hold up to that malt bill.
the only belgian ingredient you have - is special B. Special B can be used in almost any ale without contributing a belgian flavor. For a true belgian you really need to be using a belgian yeast. Belgian yeast is where belgian ales derive a majority of their character. You will get some esters from S-04, but they wont be the same (there are several types of esters). I suspect you will end up with something closer to an undefined ale. It will be interesting, but probably wont taste much like a belgian