So to be fair, I did. No where in the instructions, after the 4-6 days, which at the making of this post was, does it tell you to put the Spraymalt, DME whatever the heck this stuff is, in before going into the carboy for second fermentation, or conditioning.
Spraymalt is just the traditional British name for dry malt extract (DME), because it's spray-dried. Think of it as beer-flavoured sugar. So if you add 2+lb of it (before pitching the yeast, as one of the main fermentables), it's going to have a noticeable effect on the final flavour compared to using ordinary white table sugar. But that final 3oz of sugar is just to give the yeast a bit of food to turn into carbon dioxide in the bottle, to make it fizzy. 3oz is not going to have a meaningful effect on flavour, so you might as well just use ordinary sugar.
So normally the only time you would add DME would be before pitching the yeast. From your original post before you edited it, it seemed you were talking about this point in the process, hence the reference to this part of the instructions :
We would encourage you to consider using spraymalt in place of some of the brewing sugar, which will increase the final body of your beer...start boiling 3.5 litres (6 UK pints) of water. Open the can and pour the contents into your cleaned and sterilised fermenter.• Add the boiling water to the fermenter and 1kg (2.2lbs) of sugar (preferably brewing sugar).• Thoroughly mix the contents of the fermenter to dissolve the sugar and malt extract.• Add 17.5 litres (31 pints) of cold water to bring thevolume up to 23 litres and stir well.• Sprinkle the yeast supplied onto the surface of the beer (no need to stir).• Cover the fermenter, place in a warm area at 18-21°C (65-70°F) and leave to ferment
But if you're talking about adding the 3oz of sugar at the end of the primary fermentation to create the fizz, then you **must** do this, per bullet point 10 of the instructions :
Siphon the beer into strong bottles or a pressure barrel.
Notice the emphasis on "
strong" bottles or a "
pressure" barrel. Creating the fizz creates gas pressure, which an ordinary glass carboy cannot hold - in fact doing a secondary fermentation in a sealed glass carboy turns it into a bomb capable of throwing shards of glass at high speed into your face.
This is incredibly dangerous - if you have a gas-tight seal on the carboy (eg a bung) and not eg an airlock then you need to release the pressure
as soon as possible.
The other reason for moving the beer into another vessel is that the carbon dioxide gas that gets released in any fermentation can stay dissolved and the wort can become super-saturated with CO2. As you have found, adding nucleation points in the form of sugar crystals allows the excess gas to come out of solution violently, in the form of a geyser.
The act of transferring the beer to another vessel knocks the excess gas out of solution, "defusing" the potential geyser.
But if it is really at 1.030 (have you
temperature-compensated your hydrometer reading? Or are you using a refractometer?) then yes, you've not finished fermentation and it just needs more time (and/or a higher temperature) before you even think about packaging it.