Ideas to control beer temperature please.

[Nozzle]

help reflect heat into the brew

Only if your heat source happens to be hot enough to be radiating light/infra-red. Otherwise, (what with aluminium being a reasonably good conductor) your strip of foil is probably doing the opposite of what you think it is.

Nozzle

 

[ericmark]

I seem to remember light has a detrimental effect on beer, not cider and other drink, it is just beer it is called "skunked" the light interacts with the beverage' s hop-derived compounds and forms a chemical often compared to the odour of a skunk' s spray. So in real terms I should not use a bulb to heat it, however I have never noticed the smell myself, so not really worried about it, however @Nozzle is correct anything covering the beer should in theory be black on the inside to absorb light and turn it into heat.

@Munroist point about time heat belt is required I know from the past in an insulated box (freezer not turned on) a single 8W bulb was enough to keep it warm, idea is a constant temperature so heater should be just big enough, or a hysteresis will start, and 40 pints takes a lot of heating and cooling, so with 0.5°C slewing my simple bulb is running for around 50% of the time, and there is two cycles per day approx, the fish tank heater monitors within the test tube so cycling is rather rapid, but designed to heat an uninsulated tank, fish tanks are not normally double glazed, and we want to see the fish, however a brew belt "The heat belt is permanently on and has no thermostat, heat can be regulated by moving the Brew Belt higher or lower on the vessel - move it lower for more heat, or higher for less heat." who are they kidding, once the circulation has started it will heat the whole fermentor to same temperature at bottom or top as long as the other side of the fermentor has liquid touching the plastic walls, and 25 watt would likely heat brew to 20°C plus even in an unheated garage.

I tried the manual switch on/off method before, and the heater was just 15 watt not 25 watt, and I was using a stick on temperature strip, lucky I did not kill the yeast when it hit 32°C and the beer was very bitter as a result of the over temperature.

This transformed my beer making, today you can buy Inkbird 308 ready made version, but then the STC-1000 was the main unit used, less than £10 but it needed boxing and by time I had bought the grid sockets etc it likely cost more than the Inkbird. I did all sorts of experiments, and found putting sensor against formentor under a sponge and buggy cord was close enough there was no more than 1°C measured in different places in the brew, there was good natural circulation.

My problem was I had left the heater behind, and was trying to think of another way until travel restrictions lifted and I could collect rest of my stuff. Seems my son has loaded a trailer it is all ready to simply hitch up and go, but North Wales police are stopping travellers and my car now registered in Mid Wales.

And if I am honest I don't need the stuff left behind in old house, it can stay there a year if needed. Although I would prefer to sell the house, but that is not going to happen yet.