Third Mild Kit success....ish

[ni9e]

This time I tried a youngs mild kit and woohoo it has turned out ok ish I used 1Kg Brewers sugar instead of Beer enhancer and also used safale 04 instead of suplied yeast.

Been in the keg 3 weeks but has a homebrew twang and is very thin hoping it improves over time but no infection this time

I am ordering a Brewers Choice Stout kit next is there any way I can improve this beer i'm thinking of using 1Kg of medium spraymalt coz if this kit tastes like homebrew then I'm going All Grain

[ni9e]

So light spraymalt is what I'll use would it be best to use to use all spraymalt or with a mixture of brewers sugar.
If I use 1Kg of spraymalt will this affect the FG if so what reading should I be expected to be reading?