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DiBosco

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I've recently bought a new, bigger kettle so I could boil more beer at a time. Seemed like very little effort for twice as much beer. Gone from the Peco 23litre to a 56 litre stainless steel kettle.

I still used the Peco for HLT as it's nice that you can set a temperature and it will keep it there. I assume this uses a relay or a TRIAC in a very basic way as when it gets to temperature it just seems to switch the power off and on completely.

This new kettle has no temperature control. It just boils away while it's powered up.

I used to Peco to give me 23l for the original mash and another 23l for the sparge and used twice as much grain as I usually do.

I ended up with about the same amount of beer as I have done with the half sized kettle. So, I'm wondering whether the very aggressive boil with the new kettle has lost me a whole pile of beer. Is that possible?

I'm an electronics engineer and I could knock up a system, I think, that would, once up to temperature, reduce the current going through the element which would keep the temperature at a steady 100 degrees, rather than the 104 ish that it went to while boiling with this new kettle. (Assuming I could find a temperature sensor it was safe to drop in the beer! :D) Is this a good idea? Has anyone else done something similar or know of it as being a normal way of controlling boils?

Many thanks!
 
A hard boil is a good thing because it increases the chance reactions happening in your kettle as the wort boils (the science is out there). You will, of course, lose more water through evaporation. Your choices are to work out how much, and start with the extra; top up with kettles of boiling water as you go; top up with boiled and cooled (even frozen) water afterwards.
This evaporation is useful if you want to make high-gravity, barley wine type beer.
Something to consider- if the chance collisions are happening more frequently because you're moving the wort around faster, it could be that you need shorter boils. Once you achieve "hot break" its possible that further boiling might start breaking up the clumps of protein that you wanted to create.
Having said that, if I were you (I'd have the skills then :???: ), I'd rig up the thermostat to save electricity. You'd probably need to make or find some kind of thermowell (thermopocket?), either poking through the side of your vessel or through the lid, insert the probe into that.
 
I think the thing that makes me think it would be a good idea is possibly losing a whole load less beer at the end of the boil. When I've used the Peco the quality of the beer produced as been excellent and that seems to switch off for 30s-1minute once it's hit boiling, then switches back on again. If I can control the TRIAC so the element is still on, but just at a lower level, I reckon that should be even better. In theory!

Plus, as Rob says, I could save some electricity! I wouldn't be surprised if the big brewers are very keen on that, the scale they go at!

Thanks to all!
 
@Twostage The controlling device you're looking for, I think, is a TRIAC based controller - which is like a transistor for switching on and off ac (rather than dc). If you want to reduce the effective current going through the element, you can use the TRIAC to only apply power for part of each cycle of mains. Mains goes at 50Hz passing through 0V and up/down to +/-340V or so in a sine wave pattern. You can detect when the voltage goes through 0V and then switch on the TRIAC some time after it goes through 0V. You switch it on by applying a momentary voltage to the TRIAC's gate then the current is passed through the TRIAC and to the element until it passes through 0V again.

The longer you wait after it has passed through 0V before switching the TRIAC on, the lower the average current going through the element, the less power you're putting into the element and therefore into the beer. It's what's used, essentially, in old fashioned tungsten filament light dimmers in homes.

What I intend to do is use a microcontroller to monitor the temperature and when it hits 100 degrees, reduce the power so I get a less agressive boil, but it is always boiling (simmering?) away. (Unlike the Peco which seems to actually switch the element off altogether). I think this should work well and I'd be surprised if that's not what breweries do (only on a much bigger scale).

@DoctorMick Goodness knows. I hadn't thought it was *that* much, but my 60 litre fementing vessels looks sadly not-very-full right now! I lost 5 over litres in the bottom of the kettle that wouldn't come out of the tap so must have lost an imperial s**t load in the boil! :-P I don't remember seeing a small lake on my kitchen floor. :-D
 

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