With most kits you use tap water, when making from grain you boil or at least take things to a high temperature likely to kill any bugs. So with a kit you need alcohol fast, then that alcohol kills the bugs. Kits do vary in temperature, but this is from a Coopers kit.
Important: If the wort is not at ideal temperature but within the range of 18ðC-32ðC (64ðF-90ðF) add the yeast. At this point the wort is vulnerable and prompt addition of yeast is more important than ideal temperature.
So with a kit you are aiming for a light beer taste rather than a true lager. It would be nice if you could read a review and work out which kit is the best. However when you read reviews 95% of them start with "I replaced the sugar with brew enhancer/sprayed malt/honey" or some other move away from the instructions. Nothing wrong with altering the kit, but it means the report is next to useless.
I have also found temperature changes what is a good kit to a poor kit and most people who are still using kits, either enhance them or have no temperature control. Myself included. So if I look at a kit I did two years ago it was done with simple sugar, but temperature could be anywhere. And look at kits done this year, only one with simple sugar and that was not lager.
So the only reason to look at yeast in early stages is when you can't maintain the temperature required for the yeast supplied. But the yeast does change the taste, so kit manufacturers match the wort to yeast supplied. So if you can maintain 20ðC go for an English kit, but if the temperature is likely to reach 25ðC then go for an Australian kit where they seem to include yeasts that need a higher temperature.
I tried brewing in an old fridge/freezer without using the motor, in the main because I had bought wrong temperature controller which would control heat or cool rather than heat and cool. Once the first 10 days are over the insulated box is good, and a simple heater will maintain temperature, it is rare for the ambient to rise to a point where it gets too hot. However in those first 10 days the heat from the fermentation means the ambient needs to be below 16ðC to maintain 20ðC in the fermentor in the fridge compartment. Even then you need to start at no more than 18ðC which is just on the limit for yeast to start. Better if ambient is less than 14ðC. OK today 11th August 0:02 am outside is 12ðC, but it is likely tomorrow will get hotter so you need to start brew with fridge door open and pray for first 5 days at least to be cool.
I also made a mistake measuring the fermentor temperature, I used a stick on strip, it had 16,18,20,22,24 etc marked, but it measured somewhere between fermentor temperature and ambient temperature because it was exposed to the air, when I started to use a temperature controller I found with a sensor under a sponge so insulated from air temperature and only measuring fermentor temperature the temperatures of the strip and controller did not match. The difference between to two varied first 5 days the sensor was recording up to 3ðC higher than the temperature strip, but as time went on the temperatures became closer. The bigger the difference between ambient and fermentor temperature the more out the strip is, so when my strip measured 26ðC likely the fermentor was really at 30ðC no wonder my early brews in summer were poor.
What I did was start mid September when forecast was cold for 5 days, and last brew started end of May weather permitting. I would use two fermentors so 40 pints every 10 days and I would try to build up a stock. But last March I was ill, so the brewing stopped, as a result I ran short on stock, so bought a STC-1000 and started using the freezer to brew in. So this year is first year I have brewed in the summer.
Having a stock of beer in the shed does however have an advantage, it is all well conditioned before drinking.
My lager attempt was with Geordie kits, I did two as lager taste, one at 20ðC the other with lager yeast at 12ðC the latter was a total failure, it was too long in the fermentor before any alcohol was produced and it was the only one of my beers to get spoilt by wild yeast or other unwanted bugs. Unless you boil all water before using do not try to lager a kit, learn from my error. The 20ðC kit was not too bad, but lager is not my thing. I used other lager kits instead of sugar in some of my brews, and they were very good, Morrisons sold off their beer kits cheap and only had lager kits left, so I bought a few at ã6.50 each which was about the same as buying dried malt.
