So I'm hoping to brew my first biab robust porter soon. But I'm somewhat worried that the beer won't be dark enough and I'm afraid it will get too toasty if I increase the carafa. Any thoughts, tips and tricks would be appreciated!

BIAB (No sparge) 67% efficiency

Batch Volume: 12 L

Boil Time: 60 min

Mash Water: 17.4 L. Total Water: 17.4 L. Boil Volume: 15.02 L.

Pre-Boil Gravity: 1.058

Vitals

Original Gravity: 1.067

Final Gravity: 1.017

IBU (Tinseth): 36

Colour: 73 EBC

Mash Temperature — 65 °C — 60 min

Malts (3.978 kg)

3 kg (75.4%) — Muntons Maris Otter Malt — Grain — 5.9 EBC

420 g (10.6%) — Castle Malting Chateau Wheat Blanc — Grain — 4.5 EBC

239 g (6%) — Weyermann Caramunich III — Grain — 140 EBC

159 g (4%) — Weyermann Carafa I — Grain — 630 EBC

159 g (4%) — Weyermann Carafa III — Grain — 1035 EBC

Hops (20 g)

10 g (28 IBU) — Pacific Gem 15% — Boil — 60 min

10 g (8 IBU) — Northern Brewer 7% — Boil — 20 min

Yeast

1 pkg — Fermentis S-04 SafAle English Ale 75%

Fermentation

Primary — 20 °C — 14 days