Pectic enzyme
pectinase
Breaks down pectin to clear haze and free juice and colour.
Typical dose
Per the product sheet, a fraction of a gram per litre of must.
When to add it
Into the cold must, twelve hours before pitching. Heat destroys it.
In practice
Fruit pectin sets a permanent haze that no settling clears and holds juice inside the pulp. The enzyme breaks it down, clarifying the wine and lifting both yield and, in reds, colour. It must go into cool must and be given time; a must heated to help extraction has already denatured the enzyme, which is why it goes in before any heating and never after.
Linked faults are the ones this addition either treats or, used wrongly, causes. The fault page says which, and whether it can be undone.
Others in nutrients and enzymes
Diammonium phosphate
Inorganic nitrogen for the yeast, the direct fix for a starved ferment.
Complex yeast nutrient
Nitrogen plus the amino acids, vitamins and sterols the yeast also needs.
Rehydration nutrient
Primes dry yeast with micronutrients before it is pitched.
Thiamine
A micronutrient that helps a ferment finish and lowers SO2 binding.
Yeast hulls
Detoxify a stuck ferment and give the yeast a surface to work from.
Glucanase
Breaks down Botrytis glucans and speeds lees ageing and filtration.
Beta-glucosidase
Frees the bound aroma compounds locked up in aromatic white grapes.