This article is from the WineMaking FAQ, by malak@CAM.ORG (Don Buchan) with numerous contributions by others.
Hydrometer: A glass bulb with a weight in the bulb, a narrow stick like
end with a scale inside it that is used to measure properties such as
liquid density, and in the case of fermentation, usually other scales
such as Brix, Balling and potential alcohol (based on the liquid
Kit: A package containing juice concentrate and other ingredients used
to make wine. Add water and follow the instructions. Formats will
vary: Some are a can of concentrate (add your own sugar, yeast, some
other ingredients); some are 5kg to 7kg (11 lbs to 15.4 lbs) of
concentrate in a bag, complete with everything needed either in the
concentrate or seperately in the box, except water; others are 15
litres (3.33 imp. gal.; 4 USG) of concentrated juice you bring up to
23 litres (5 imp. gal.; 6 USG). There are even packets of dehydrated
juice crystals in which you add all the water and sugar. Often the
concentrate is actually a hybrid containing juices of more than one
kind of grape (California requires at 51% of a given grape to be
present to call it that variety, for instance. Other areas require
75%.) Quality is discussed in section G10. KITS VS. GRAPES OR FRUIT.
Lees: The solids that have fallen to the bottom of your fermentation
vessel. Among much else, they contain live and dead yeast.
Mead: An alcoholic beverage made by the fermentation of honey and
water. Many ingredients can be added to the basic recipe.
Melomel: A mead with fruit and/or fruit juices added.
Metheglin: A mead with herbs and/or spices added.
Must: Unfermented wine (ie. grape juice).
Pectins: Large protein molecules that don't clear properly. They're
important in jam making, but annoying and undesireable in winemaking.
Pectic Enzyme: Pectic enzymes break up pectin to make smaller molecules
that clear more easily.
Pitching: The act of adding yeast to a must. Often yeast may be added
directly to the must while still dry, but the yeast is more likely to
work if rehydrated in a cup of water first, particularly if the must is
NOT from a concentrate.
Primary Fermentation: The stage during which most fermentation takes
place, usually in a covered widemouthed vessel.
Pyment: Honey and grape juice fermented together. This can be either a
fermented combination (as a melomel) or grape wine to which honey is
added after it is finished.
Racking: Transferring wine by siphoning clear wine from one vessel into
another closed vessel without transferring the lees at the bottom of
the first vessel.
Reverse Osmosis: A method of separating various dissolved substances,
similar to what cells do, only backwards. High pressures force a liquid
through a membrane with very fine pores. Typically we are interested in
city water being forced through an RO filter to produce an ulra-pure
water for the purpose of either reconstituting concentrated juice or as
part of a fruit wine recipe so as to avoid off flavours or other
undesired dissolved solids.
Riddler: Two planks with a hinge holding them together end to end, holes
along their length wide enough to hold the necks of champagne bottles,
and a chain or rope on each side that are used to adjust the distance of
the bases of the boards, and therefore the angle at which the boards are
to horizontal. See section G18. SPARKLING YOUR WINE.