Yeast

I am brewing coopers english bitter kit with LME, after 8 days fermenting at 15 degrees C , OG 1.040 became 1.012 for 2 days with kit provided yeast. I decided add 300 grm sugar with some LMe and refermenting, springkled half sachet safalle s-04. Any one could help me by giving information wether okay to mix 2 strain of yeast?
Any possibilities while brewing contaminated with any other stuff cause the wort being harmfull for health ? Thanks a lot for forward information

 

+1

Be a bit careful when adding sugar. You dont want more than 5% of your extract coming from sugar.
The 5% is just general, for an IPA you could have a bit more. Some beer styles could be ruined by adding to much sugar.

 

Using more than one strain is done for various effects--two strains with different fermentation profiles. However, they are either pitched together or occasionally one is used to clean up after another (like using a high alcohol tolerance yeast to knock of a few gravity points from final) or to add certain characteristics in secondary (as when using Brettanomyces in secondary).

It doesn't sound like you have any need for a second strain or will get much benefit out of it.

As for the added sugar, the only reason this would be done is to push up the gravity and, with it, the alcohol. However, doing so comes with a cost to other flavors, with the balance of the beer, and to mouthfeel. Why not enjoy the batch you have made, the way it turned out and if you want a bigger beer make one next time? If you feel you have to add something then consider something that will add some character to your beer and not just a bigger buzz?