For steeped grains plus malt extract:
JCP 2021 description: "Pale ale, amber, or crystal malts. May use a touch of dark malt for color adjustment. May use sugar adjuncts, corn, or wheat. English finishing hops are most traditional, but any hops are fair game; if American hops are used, a light touch is required. Characterful British yeast.
Vital Statistics: OG: 1.030 – 1.039, IBUs: 25 – 35, FG: 1.007 – 1.011, SRM: 8 – 14 ABV: 3.2 – 3.8%
Bitters should have a British pale ale base malt base. Medium to dark crystal malts compose up to 10% of the grain bill, but 4 to 7% is more typical. Specialty grains that promote bready and nut-like character are possibilities. Small amounts (2% or less) of roasted malts can be used for darker color. Torrified wheat is a possibility for up to 10% of the grist.
Sugars and invert sugars are possibilities for British beer styles, up to about 10%. This may be counterproductive though in a low gravity beer.
Use British hops: Kent Goldings, Fuggle, Challenger, etc. Most recipes have late hop additions that add up to about 25% of the hops. The BJCP style guidelines state that emphasis should be on the bitter hop addition rather than late hops. Hop flavor is described as "moderate to low." A BU/GU of .79 is a goal to aim for.
Dry hopping is possible, as in English cask conditioning. Use restaint because bittering is the primary hop quality.
British ale yeasts should be used. Posibilities are Wyeast 1968 (london esb), White Labs wlp0002 (English Ale), Wyeast 1335 (British ale II), and similar ale strains. For dry yeast, try Fermentis S04, Lalbrew Nottingham, or Lalbrew London ESB.
Beer-analytics.com ordinary bitter
Strong, G. (2017, September). British bitter: A proper pint. Brew Your Own, 28 - 32.
Zainasheff, J. (2007, March-April). Ordinary bitter: It's not so ordinary after all. Brew Your Own, 19 - 22.