What is a beer kit?
Beer kits from manufacturers typically contains liquid or dry malt extract which when diluted with water produces wort.
The extract is normally hopped, which removes the need for boiling it with hops.
Kits with lower malt content (usually up to 1.8kgs) require sugar addition.
The “all malt” style kits containing 3kg or more (to make 23 litres) normally need no sugar to be added. These kits will produce a higher quality beer.
Always check ingredients list though. It should say malt extract and nothing else (no sugar syrup, barley syrup or anything with sugar – in that case you have a cheaper beer kit dressed up as an exclusive one).