Here are the beer cellar reviews, listed according to their scores. Those graded with identical scores are listed together, without any significance to their internal order.
| Top Scoring | Alphabetical (by beer) | Alphabetical (by brewery) |
| Beer | Brewery | ABV (%) | Comments | Score:/10 |
|---|---|---|---|---|
| O'Kane Red | O'Kane? | 0.00 | Watery barley water, which has been shown a bottle of Ribena, once :( | 5.0 |
| O'Kane Stout | O'Kane | 0.00 | Watery, with nothing memorable. Thicker consistency when on draught. | 5.0 |
| Oatmeal Stout | Buntingford | 4.40 | Solid chocolate mild, with bitterness bite on back of palete. Solid taste. Slight coffee tang to it. | 7.5 |
| Okells Alt | Okells Brewery | 5.00 | Dark copper, cream head, and smooth. Not at 'alt' in the traditional sense. | 7.5 |
| Okocim Porter | Okocim (Carlseberg) | 8.30 | A touch of sweetness, and strong coffee bitterness throughout. Not strongly balanced, as hop is lost, and bitterness takes oer | 6.5 |
| Okocim Porter | Okocim (Carlseberg) | 8.30 | A touch of sweetness, and strong coffee bitterness throughout. Not strongly balanced, as hop is lost, and bitterness takes oer | 6.5 |
| Old Arthur | Big Lamp | 4.25 | Thin textured with cider flow,but with bitter head. Has notes of lime. | 7.0 |
| Old Bloomer | Concrete Cow | 4.70 | Light ruby in colour, and put under the 'best bitter' category. Overiding hazlenut flavours, and strong pungent aroma to match. Vibrant fizzy ale, which settles down in aftertaste. Slightly sharp. | 5.0 |
| Old Bob | Ridley's, through Greene King | 5.10 | Rounded, smooth, red bitter. Dark fruity aroma. Enjoyable direct mouthfeel. | 8.0 |
| Old Engine Oil | Harviestoun | 0.00 | Black, no head, molasses, touch of licorice without the aniseed bit (i.e. sugar cane syrup) but moderately thin on quaff, filling out on tonigue with mouthfeel. (Sim. Meantime porter, but better) | 7.0 |
| Old Growler | Nethergate Brewery | 5.50 | A true winter beer. Deep ruby colours, with smooth roast malts and fruit tangs. Touch of licorice. Better than Pied Boeuf. | 8.5 |
| Old Lager | Mutzig | 6.90 | Means "old lager", and stronger than the standard (4.5%). Standard clean French lager, transient after taste. Drink in glasses - not pints. | 7.0 |
| Old Monty Dry Cider | Montgomery Cidermakers | 6.00 | Golden haze, sour Welsh cider. A little rough, ends well with tight dryness | 7.5 |
| Old Moor Porter | Acorn | 4.60 | Creamy porter with burnt roasts which hold in the mouth. Some licorice flavours, but mostly overpowered by the roast aroma. Quite filling. | 7.0 |
| Old Slug | RCH Brewery | 4.50 | Coffee and chocolate focused porter. Notes of blackcurrant and black cherry. | 6.5 |
| Old Tom | Robinsons | 8.50 | Strong ale, good lasting head. Warm pepperish taste that's pure liquid licorice. A comfort beer, in every sense. | 9.0 |
| Old Trip | Hardy and Hansons | 4.70 | Fizzy head, thin but firm bitter taste. Really good bitter on aftertaste. | 7.0 |
| Old Wallop | Davy's | 4.80 | Malty, light co2, but rich beer similar to Directors or Speckled Hen | 7.5 |
| Oldfield SV Perry | Oliver's Orchards | 6.00 | Sharper and sweeter than the Hecks Blakeney. Still good. | 7.5 |
| Oliver's Downfall | Cromwell's | 6.50 | Slightly tart, medium sweet, cider. Matured in whisky casks, not that you'd tell | 7.0 |
| Op & Top | De Molen | 4.50 | Dutch hoppy beer. Trying to be too clever, and turns out like every other hoppy 'artisan' beer | 7.5 |
| Organic Blonde | Hepworth | 5.00 | Clean golden colour and strong floral aroma. Similar to Asahi. Touch fizzy on start, settles to easy malt base. Lack of real a/t (but unlike Asahi, still strong on palete) | 7.5 |
| Organic Dark | Freedom | 4.70 | Not dark, but dark golden/ruby with a soft cream and light bitterness. The bitterness re-touches the palate in the aftertaste. Touch of sweetness | 8.0 |
| Original Sin Pear Cider | Original Sin | 6.00 | Drinkable but so non-descript, I didn't bother making notes. | 6.0 |
| Orkney Blast | Highland | 6.00 | Golden fullsome mouthfeel to remind you it's light , but strong biscuit malt a/t ultimately sits heavier on pallet. Woody aroma. | 7.5 |
| Oscar Wilde | Mighty Oak | 3.50 | A good mild with hints of chocolate, malt, and coffee. | 8.0 |
| Otley Garden | Otley Brewing | 5.40 | Honey touches throughout beer - mouthfeel, taste and follow-through. Light, murky (but pleasant) visually, with light co2. | 8.0 |
| Oude de Geuze | Chapeau De Troch | 6.00 | Very sour, straight apple fruit hit. Slightly cloudy with a golden haze. | 7.0 |