Hey NewtoBrew...
I'll elaborate a bit more on what I said. Usually kits say in the instructions to add your kilo of fermentables (sugar or malt or brew enhancers etc), the kit contents and 2L of boiling water to your fermenter. They then usually say swirl or mix the ingredients together and top up with cold water. This works okay for some, but I suspect that most sugars (particularly dried ones) are a potential source of infection if they are not fully sterilised by boiling first. I always boil my primimg sugar in a equal quantity of water too before adding to my brew for bottling. (For example, 3/4 dex in 3/4 water to prime a 23L batch).
So, what I do is usually pour 1.5 - 2L of boiling water into a big pot (=a brew kettle), add my 1kg of fermentables and boil it for about 5 minutes. I then turn off the heat and mix through the kit contents (I clean out the tin with about 250mls of boiling water). Adding the kit drops the temperature of the kettle's contents probably by around 30 degrees C. So were not dealing here with boiling liquid anymore. If you are worried about though what you can do is add some of your cold water total to the brew kettle to cool it down a little before pouring it into your fermenter. You''l probably need to add some cold anyway to clean every last vestige of beer concentrate out of the kettle.
With regards to hops additions, all you do is bring the 2L hot to a rolling boil with your kilo of fermentables and then add your hops additions. I usually just do flavour and aroma additions with kit and kilo recipes so the most I boil for is 40 minutes (with the lid on to reduce evaporation). Most of the time I only boil aroma additions for 5 minutes and then I alllow it to cool for a few minutes. I then strain into the fermenter through a sanatised sieve. In this case, I would usually have just poured the kit contents into the fermenter already. I then mix it all up and top up with cold water.
Another thing I do is use specialty grains like chocolate and crystal malts. In this case I steep the cracked grains (usually around 200g of crystal or 50 - 100g of chocolate) in 2L of 66 - 70C water for 30 minutes to 1 hour. This temperature releases the grain's voodo without realeasing the astringent flavoured tannins in the husks which can ruin your beer. I then strain the specialty malt steep liquid through a sieve and rinse the grains a little with hot water to get out the last bits of flavour. I then use the resulting liquid just like I describe above with a regular 2L boil with my kilo of fermentables. The rest of the steps are the same.
Some people recommend boiling the kit contents too and I used to do this, but I don't think it's really necassary sanatation wise and it may boil off some of hop aromas from the kit.
I hope this helps.
Great , Thanks Wildschwein
