the yeast is from previous brew that was saf s23 and was taken from 2 stubbies and made into a starter but used dextrose and some nutrient this yeast then did not ferment out stopped at 1016 its now in 8 x 3 L fruit juice containers in fridge as this is the only way to fit 2 brews in fridge.Another brew was then put onto yeast cake but only 17 L of water no dextrose which is now fermenting the question is what happens if you put the 1 kg dextrose and 5 L at a later stage will it ferment better as the dextrose will be last to ferment out .In wine making if you want high alcahol content they recommend adding sugar in stages .The second question is when making yeast starter from brewed beer can you ruin yeast by feeding dextrose .
Mate, really think you may need to have a look at some of the standards used in making a yeast starter.
Dextrose is no good . Re-hydrating and building starters are different things, as is growing yeast from bottle yeast .
.If you want to build a starter..that is make alot of HEALTHY yeast then you need to use malt extract . This is a simple wort . You need to boil it. Cool it. Then pitch your yeast .The let it start to grow . Have a look at some of the wiki and or search functions to learn more.
If your beer has finished fermenting , IMO adding more water and sugar will not kick it off again . I would not add more water and sugar .I would also suggest becuase your OG may be higher ,your FG may not be as low as you would expect . I would try giving your fermenter a gentle swirl to rouse the yeast and see if that helps .
I am still unsure what you mean by ferment better...do you mean quicker ? lower FG ?
Adding more sugar will only ( in my opinion) lead to it tasting bad.
Beer making and wine making are different in alot of ways . Some practices do not transpose.
I cannot stress enough that it sounds like you really need to do some more research on good brewing practices .
Another thing..PUNCTUATION .
It is very hard to read your posts when you fail to use full stops and are not overtly clear on what your problem is and what your questions are. Be concise in what your methods are too...this can help others ( inc me ) help you .
Lastly...your brews are in 8 x 3 litre juice containers ?????? How sanitary are they ? Do they seal properly ??? Maybe get some long necks from the scouts/buy and drnik some/whatever...they don't all have to be in the fridge once you bottle...in fact they may benefit from some conditioning to help your carbonation .
Anyway...this is just my 2c....
Lets hope we have no-more exploding heads....
Ferg