The beer probably had the following characteristics:
- 2.8% to 3.2% alcohol by volume
- Color of SRM 2.24 to 3.98 degrees Plato
- Bitterness in the 9.9 to 16 IBU range
Considering that it may have taken on water and that hops bitterness degrades over time, it's probably fair to bump all those numbers up a little. Maybe a good approximation of the fresh beer before sinking into the ocean was:
- ABV: 4-5%
- SRM: 4-6
- IBU: 16-22
That would put it in the ballpark of a Blonde Ale, which is in the 15-28 IBU range, with a color in the 3-6 SRM range, and relatively low alcohol content.
Blonde Ales typically are all-malt beers, but some use wheat malt or sugar. To get that Apple-flavored variant, maybe you'd add some apple juice before bottling. For the rose-flavored one, I might drop rose petals or rose hips in during the last few minutes of the boil.
The following recipe reportedly makes a blonde ale that's in the range we're looking for:
- 9.5 pounds of 2-row Pale Malt
- 1 pound of Munich Malt
- 1 pound of Carapils or Carafoam
- 1.25 ounces of Hallertau (4.8%, 60 min.)
- 1 ounce Saaz (4%, 5 minutes)
- White Labs WLP001, Wyeast 1056, Safale S-05, or White Labs WLP029 with a two liter starter
Mash at 154 degrees Fahrenheit for 30 minutes. Sparge the grain. Boil for 60 minutes. Cool and ferment at 67%.
I might consider toasting some of the pale malt (not more than a half-pound) to replicate that "brewed over an open fire" element of the flavor... but I'd probably only do that after trying it without.
In the case of the rose-flavored beer, I would probably add about two ounces of rose petals (sterilized) into the fermenter near the end of fermentation (and of course remove before bottling). The Hallertau and Saaz in the recipe are described as having floral characteristics and might be a good match.
For the apple-flavored one, I might add 2-4 ounces of LD Carlson's Apple Extract. Apple juice or fresh apples would give it a tart, cider-like flavor. If I used fresh apples I might swap a pound of the Pale Malt for another pound of Munich to offset the tartness with some sweetness.
If you try it, let me know how it turns out...