ericmark
Regular.
Since starting to brew some 3 years ago my methods have changed. The first method was to watch the air lock, this caused problems as the air lock leaked and temperature also affects rate of fermentation, however I stopped the air lock leaking by using a stuffing gland. And although the hydrometer was used to confirm what the air lock showed, it was the primary quick check.
Then I moved into a fridge, could not see air lock without opening the door and as a result it was not really any easier watching an air lock as to use hydrometer, plus now near ever brew took same time, using Youngs Harvest Scottish Heavy kit nearly every brew and set at 19ðC I could happily just leave for 10 days, swap to clean fermentor leave another 10 days and bottle. Yes I did check with hydrometer but don't know why, the reading was same every time.
However now moving into summer months I have noticed another indicator as to brew progress, and that is the freezer air temperature, I have always measured fermentor temperature to control so with controller set to 18.5 ~ 18.8ðC I have noted the freezer air temperature starts at around 16ðC once settled down, and slowly climbs as the brew progresses, once the major part of fermenting has completed the air temperature equals the fermentor temperature.
As to this being of any use I don't know? When heat is required then there is always a gap between freezer air temperature and fermentor temperature, only when cooling do it seem to show how it has progressed. Since I will still leave 10 + 10 days it does not really alter what I do. Other than confirm fermentation is actually taking place.
During the winter months heating the brew had no real surprises, it did as expected, I used an energy meter to work out average power used and even in heart of winter in my freezer in integral unheated garage 5W was maximum average power used, an 8W bulb was ample to maintain the 19ðC I had selected. I found brewing in the fridge my 18W under floor heating tile was too big, it would over shoot, specially as the winter was left behind and I realised I would need to reduce the output of the tile.
Summer however has not been the same, once cooling was required, I found my fridge/freezer sent hardly any cooling to fridge so no option but used freezer compartment, I expected a large over shoot using a simple controller with sensor on the fermentor, I was wrong, it did not even over shoot by 0.1ðC even when on first switch on the freezer air went down to 5.6ðC. I found setting at 0.1ðC differential was not required 0.3ðC was ample, even with sensor on the fermentor in fact if it had been in the air it would have needed to be much larger a differential set, as it is the freezer does not run for very long each time it switches on, total power used over 4 days set to 18.5ðC is just 0.49 kWh even when ambient in garage is over 20ðC most of the day.
I had expected to be forced to measure freezer air temperature for the controller, I was completely wrong. This does not seem to line up with comments on the forums where prior to doing it myself, I was told how I would get a yo-yo effect as both heating and cooling over shoot. Heating yes I had to use a far smaller heater than I expected to stop over shoot, but cooling it has been spot on. One fact maybe which has a bearing on this is with a frost free freezer and with an upright freezer one can only use a frost free as other wise the evaporator is in the way, there is a built in fan, that's how it works, the evaporator is behind a shield kept away from food, and at a set time a heater melts off any ice formed on the evaporator with the fan not running so only the evaporator is heated, but on the cool cycle the fan circulates the air. As my temperature controller switches on I hear the fan start, the freezer does some self checking and the freezer motor starts some 3 minutes after the fan. On first switch on it took some 40 minutes for the fermentor to cool from 20.4ðC to the set 18.5ðC and in that time the freezer air went down to 5.8ðC. On the controller switching off there was a rapid warming of the freezer air to 9.2ðC before the fermentor warmed to 19ðC switching the controller on again, (there was a 15 minute delay set) and hit 11.5ðC before the freezer motor started, that was just 18 minutes of freezer motor not running for temperature to go from 5.8 to 11.5ðC the reverse is not true, when the heater over shot to 22ðC when set at 19ðC it took a couple of days to cool down again even with ambient in garage at 16ðC.
I have really been surprised at cooling, it was not anywhere as hard as I had been lead to believe. Plus it also seems to show how fermentation is progressing.
Then I moved into a fridge, could not see air lock without opening the door and as a result it was not really any easier watching an air lock as to use hydrometer, plus now near ever brew took same time, using Youngs Harvest Scottish Heavy kit nearly every brew and set at 19ðC I could happily just leave for 10 days, swap to clean fermentor leave another 10 days and bottle. Yes I did check with hydrometer but don't know why, the reading was same every time.
However now moving into summer months I have noticed another indicator as to brew progress, and that is the freezer air temperature, I have always measured fermentor temperature to control so with controller set to 18.5 ~ 18.8ðC I have noted the freezer air temperature starts at around 16ðC once settled down, and slowly climbs as the brew progresses, once the major part of fermenting has completed the air temperature equals the fermentor temperature.
As to this being of any use I don't know? When heat is required then there is always a gap between freezer air temperature and fermentor temperature, only when cooling do it seem to show how it has progressed. Since I will still leave 10 + 10 days it does not really alter what I do. Other than confirm fermentation is actually taking place.
During the winter months heating the brew had no real surprises, it did as expected, I used an energy meter to work out average power used and even in heart of winter in my freezer in integral unheated garage 5W was maximum average power used, an 8W bulb was ample to maintain the 19ðC I had selected. I found brewing in the fridge my 18W under floor heating tile was too big, it would over shoot, specially as the winter was left behind and I realised I would need to reduce the output of the tile.
Summer however has not been the same, once cooling was required, I found my fridge/freezer sent hardly any cooling to fridge so no option but used freezer compartment, I expected a large over shoot using a simple controller with sensor on the fermentor, I was wrong, it did not even over shoot by 0.1ðC even when on first switch on the freezer air went down to 5.6ðC. I found setting at 0.1ðC differential was not required 0.3ðC was ample, even with sensor on the fermentor in fact if it had been in the air it would have needed to be much larger a differential set, as it is the freezer does not run for very long each time it switches on, total power used over 4 days set to 18.5ðC is just 0.49 kWh even when ambient in garage is over 20ðC most of the day.
I had expected to be forced to measure freezer air temperature for the controller, I was completely wrong. This does not seem to line up with comments on the forums where prior to doing it myself, I was told how I would get a yo-yo effect as both heating and cooling over shoot. Heating yes I had to use a far smaller heater than I expected to stop over shoot, but cooling it has been spot on. One fact maybe which has a bearing on this is with a frost free freezer and with an upright freezer one can only use a frost free as other wise the evaporator is in the way, there is a built in fan, that's how it works, the evaporator is behind a shield kept away from food, and at a set time a heater melts off any ice formed on the evaporator with the fan not running so only the evaporator is heated, but on the cool cycle the fan circulates the air. As my temperature controller switches on I hear the fan start, the freezer does some self checking and the freezer motor starts some 3 minutes after the fan. On first switch on it took some 40 minutes for the fermentor to cool from 20.4ðC to the set 18.5ðC and in that time the freezer air went down to 5.8ðC. On the controller switching off there was a rapid warming of the freezer air to 9.2ðC before the fermentor warmed to 19ðC switching the controller on again, (there was a 15 minute delay set) and hit 11.5ðC before the freezer motor started, that was just 18 minutes of freezer motor not running for temperature to go from 5.8 to 11.5ðC the reverse is not true, when the heater over shot to 22ðC when set at 19ðC it took a couple of days to cool down again even with ambient in garage at 16ðC.
I have really been surprised at cooling, it was not anywhere as hard as I had been lead to believe. Plus it also seems to show how fermentation is progressing.
