Adapted from "First steps in winemaking" by C J J Berry

Chamber of Horrors!!!

Click on the symptom...

Acetification:  ... or formation of vinegar.  Caused by poor storage and presence of air.  Remedy:  Always keep fermenters full.  If detected early it can be halted by adding 1 campden tablet per 5 litres.  Later development reduces the wine to vinegar and can only be tossed down the sink or used for cooking.

Acetone: ... or nail polish.  Caused by not plunging the cap (the fruit solids that rise in the primary fermenter).  Whilst the fruit is in contact with the must it needs to be plunged 3 times a day.  Theis also stops the cap from going mouldy.
 

Over-sweetness:  Caused by too much sugar for particular yeast or low nutrient or cold temperatures.  Remedy:  Blend with a dry wine.  Finish the ferment by adding a stuck yeast and more yeast nutrient.

Dull:  Flat or insipid wine, caused by lack of tannin.  Remedy:  Add grape tannin or soak an apple peel or oak leaves in wine or a tablespoon of strong tea per 5 litres.

Too harsh:  Add a teaspoon of glycerine per 5 litres or use gelatine finings (1 teaspoon in a little warm water per 5 litres) allow a couple of days with stirring.

Too much acidity: Sourness caused by under-ripe fruit.  Remedy:  Mask with a teaspoon glycerine, or sugar (5g/L) if only slight.  If extreme, reduce with potassium carbonate or calcium carbonate.

Too little acidity:  Flabby wine that falls off the tongue.  Remedy:  Add citric or tartaric acid to taste.  Usually 7g per 5 litres raises acidity by 1 ppt.

Not enough body: Remedy:  Add 250g raisins per 5 litres or add glycerine or juice of 2 bananas or make a note to use more fruit next time.

Too spiritous:  Caused by too much sugar/fruit ratio in original gravity.  By using more fruit per 5 litres you can drop the amount of added sugar for a wine.  Remedy:  Add water to initial must to get the gravity lower..

Low alcohol content: Usually allied to over-sweetness.  If it is the result of a incomplete ferment, pitch a stuck yeast with some more yeast nutrient.  Can be due to under ripe fruit - bulk out the wine with 250g raisins/5l.  Make a note to increase fruit/sugar ratio next time.

Poor bouquet:  Usually caused by high ferment temperatures resulting in a rapid ferment or poor ingredients or too much nutrient.  Remedy:  Keep up the acid level by using citric, malic or tartaric acid.  Use rose petals, elderflowers or raspberries in the recipe next time.

Slightly off smells:  Caused by bacteria, poor fruit, bad cask cleaning or proximity of wine to strong smells.  Remedy:  Use a tablespoon of treatment carbon per 5 litres, stir regularly in the first 24 hours.  Allow to settle.  Leave for a further day , then rack and filter to remove the particles of carbon.

Too much colour:  Caused by bacteria, tainted plastic buckets or poor fruit.  Remedy:  Use a tablespoon of filter carbon per 5 litres, stir regularly in the first 24 hours.  Allow to settle.  Leave for a further day , then rack and filter to remove the particles of carbon.

Poor colour extraction:  Caused by low ferment temperature or under-ripe fruit.  Remedy:  Wine can be blended with 250ml elderberry wine or the tip of a teaspoon of salt per 5 litres will help fix the colour of a red wine.

Pinking of white wine:  Wine looks oxidised but the pinking obscures the greenness and brightness of the wine with no alteration to taste or smell.  Remedy:  Use 2 tablespoons of dried milk (casein) per 5 litres, rack two days later.

Oxidation:  Wine changes colour, brown at the edges or browning of wine, the taste and smell changes to something like banana skins.  Remedy:  Blend with strongly fermenting wine or use 2 campden tablets per 5 litres, allow to settle and rack.  Always keep your fermentation vessels full - make up any lost volumes from racking with sterilised marbles or sterilised bottles filled with water.  Ideally fill the receiving vessel with a CO2 blanket and fill to the bottom of the vessel to avoid splashing.

Hazes:  Pectin, smokey haze - test wine with equal quantities of methylated spirits, if a sediment forms treat wine with more pectic enzyme.  Starch - test with iodine, if positive treat wine with amylozyme.  Protein - bottled wine develops this haze over time, treat wine with bentonite or chitin, filter if necessary.  Coloured hazes caused by metallic contamination by copper, zinc or iron.  Treat with a little citric acid.  Use only inert metals or glass equipment in future.

Mousey wine:  The horrible odour of mice is instantly detected if a drop of wine is dropped on the palm of the hand and smelt.  Caused by acetimide produced by spoilage bacteria.  Remedy:  You can try reflux carbon or the sink.  Make sure to bleach all your equipment.

Flowers of wine: Powdery, whitish flecks appear on the surface of the wine and if left unchallenged will rapidly increase and will turn the wine first to carbon dioxide and vinegar then to water.  Caused by an aerobic bacterium and too much air in the vessel.  Remedy:  Early detection - filter through coffee filter paper add 1 campden tablet per 5 litres.  Late detection - wine is ruined, no remedy.

Ropiness:  The wine takes on a repellent, oily appearance, and pours very slowly like honey, the taste is not affected.  Caused by lactic acid bacterium.  Remedy:  Whip the wine into a froth in a bucket, add 2 crushed campden tablets per 5 litres and filter.

Too dry:  Use potassium sorbate and one crushed campden tablet per 5 litres, sweeten to taste.  Usually 5 - 10g per litre is enough to lift a dry wine to medium sweet.

Medicinal flavour:  Like bandaids, caused by insufficient acid in must.  Add tartaric or citric acid, 1 teaspoon per 5 litres.

Mustiness:  Caused by prolonged lees contact or dirty casks.  No great remedies.  Sharpen up your skills next time.

Failure to clear:  See also hazes.  Usually caused by incomplete ferment and early racking, subsequently leaving remaining yeast in high alcohol solution with little oxygen, low nutrient and high carbon dioxide.  The yeast remains in solution trying to complete the ferment but struggles.  Looks like a particle haze not a smokey haze.  Always make sure your first racking is NOT until all the sugar has gone - hydrometer reading of 990.  Remedy:  Restart the ferment and ferment to dryness.