Guidelines for Doctoring Beers

Recommended amounts of several substances are listed in the table below. The base beer should be a clean light lager with a crown (non-twist-off) cap so that it can be resealed after doctoring. The amounts in the table below are given for both 12 oz. (355 ml) samples and for 1 liter samples, but may be scaled to other volumes. Note that spices and other solids are extracted in liquids, since the addition of dry substances to a carbonated beer will cause gushing. For the same reason, the beers and adulterants should also be chilled to the same temperature before combining.

Flavor	Sensory Profile	Adulterant	Amount for 12 oz.	Amount for 1L.
Acidic – lactic	Clean,sharp sourness. Acidic	USP lactic acid	Make a solution of one part 88% lactic acid and four parts water. Use ½ tsp of the diluted solution.	Add 7.5 ml of the solution.
Acidic – acetic	Vinegar	White wine vinegar	3/4 tsp	10.5 ml.
Alcohol	Warming, hot	Ethanol	2 tsp straight ethanol or 5 tsp of 80 proof (40%) vodka may also be used to increase the alcohol by 2.7%.	25 ml of straight ethanol or 62.4 ml of 80 proof (40%) vodka will increase the alcohol by 2.5%.
Astringency	Dryness, harsh graininess, huskiness	Grape or wine tannin	Dissolve one part (by volume) powdered tannin in 120 parts of water. Use ½ tsp of the solution.	Use 7.5 ml of the solution.
Bitterness	Harsh bitterness	iso-hop extract	1 or 2 drops, to taste	3 to 6 drops to taste.
Clove-like	Phenolic, spicy	Clove solution	Make solution of 8 cloves soaked in 3 oz. (90 ml) of beer and add liquid to taste, about 4 tsp.	Make a solution of 24 cloves is 250 ml of beer and add some of the liquid to taste, about 55 ml.
Diacetyl		Butter extract	4-5 drops	11 – 14 drops
Estery		Banana extract	6-7 drops	17 – 20 drops
Lightstruck		N/A	Expose commercial beer in green bottles to sunlight for 1-3 days[2]	Same.
Metallic	Metal, tin-like, blood	Steel nails	mmerse four 1 inch finishing nails in the sample for 30 minutes prior to serving	Use 12 finishing nails for the same time period.
Nutty	Marzipan, almonds	Almond extract	Make a solution of one part almond extract and five parts water. Add ¼ tsp of the solution to the sample.	Use 3.75 ml of the solution.
Papery oxidation		N/A	Open bottles to air, reseal, and keep at 100 °F (40 °C) or warmer for several days	Same.
Phenolic	Medicinal, chlorospectic	Green Chloroseptic	Make a solution of one part Chloroseptic and two parts waters. Add ½ tsp of the solution to the sample.	7.5 ml of the solution.
Sherry Oxidation	Sherry-like	Dry sherry	3/4 tsp	10.5 ml.
Sulfitic		Potassium metabisulfite[1]	Make solution of one Campden tablet dissolved in 3 oz. (90 ml) of beer and add to taste (about 1/2 tsp)	Make a solution of two Campden tablets dissolved in 200 ml of beer and add to taste, about 7 ml.
Sweet	Excessive sweetness, cloying	Corn sugar	Dissolve 2 tsp sugar in 1 Tbsp water then add to the sample.	Dissolve 28 ml of sugar in 42 ml water then add the solution to the sample.
Vanilla	Custard powder, vanilla essense	Vanilla extract	Make a solution of one part vanilla extract to five parts water. Add ¼ tsp to the sample.	Add 3.75 ml of the solution.
Winey		White wine	2 Tbsp	85 ml
[1] Should not be tasted by persons with asthma or sulfite allergies.
[2] While lightstruck commercial examples can be readily found, lightstruck homebrew is extremely rare in competition settings.