Suggestions for brewing in a cold shed (on a budget)

[Zephyr259]

Thanks for the info. Have to see what's happening this weekend as I'll only just be back home from the rig. How many folks attend on average and if bringing some homebrew for feedback how many bottles is a good idea?

Edit: The wife says that I'm free and i should go meet people. So looks like I'll be there on Sunday. :-)

 

[ericmark]

The problem I found was the insulation can be too good, to begin with I brewed in the kitchen, and I used body warmers, with the air lock sticking out of the neck, the temperature in kitchen was slightly too cold, so day one no insulation, then day two body warmer on.

However when the insulation failed on the family fridge/freezer failed I thought great move to garage and garage is rather cold so will only need a heater, wrong.

The insulation on the fridge section was too good, by 10 degs C ambient on starting a brew it would over shoot, I have to start the brews in the freezer section with the STP-1000 connected to both freezer and a pair of 8W bulbs. Once it has been going 2 days then I can transfer to fridge, but keeping it cool enough is the problem, not warming it up.

I did try starting with door open but then too cold, what it needed was to be in an ambient temperature of around 18 degs to start with and 20 degs latter on once the first rapid activity had slowed. The water bath is as much to absorb the start up heat as to keep hot latter. In fridge compartment with fridge switched off, with heater set to 19 deg C and ambient outside at 15 degs C in first day it would hit 24 to 25 degs C.

I considered a green house window opener on the door, however just too complex, motor still works, so start in the freezer compartment, normally transfer after 7 days to fridge as fridge is higher so can syphon out easy to bottle. What would work is first 2 days in kitchen then more to garage and fridge compartment, but whole idea was to get out of the kitchen.

 

[Bigcol49]

Hi!
When I first saw the title of this thread I thought, "Warm coat, scarf, a good cap and don't forget your long johns."

The insulation on the fridge section was too good, by 10 degs C ambient on starting a brew it would over shoot, I have to start the brews in the freezer section with the STP-1000 connected to both freezer and a pair of 8W bulbs. Once it has been going 2 days then I can transfer to fridge, but keeping it cool enough is the problem, not warming it up.

@ericmark
Where do you place your temperature probe when the brew's in the fridge section?
What heat source are you using for the fridge section?
Do you use a water bath in the fridge?
Why don't you leave the FV in the freezer section until fermentation is complete, lift it up into the fridge section, unheated, for a few days and then transfer as normal?

 

[ericmark]

I tested with probe both in the brew and held against the fermenter wall with a sponge over it to insulate from ambient air, difference less than 0.5°C so use the sponge method all the time now. In the fridge and freezer put in an extra sensor to monitor ambient air temperature, new brew little on warm side 22°C wanted 19°C the freezer kicked in and air temperature dropped to 8°C before it cut out, however the brew temperature did not go below 19°C by even 1°C the air temperature and fermenter temperature rose again and it cut in a second time within the hour to complete the cooling. Monitoring fridge when motor cuts in seems fridge is not cooled until freezer is down to temperature, so no cooling in fridge. There is a short draw in freezer where the motor is, in the short draw on a metal plate I have an ikea cupboard lamp with 2 x 8W CFL bulbs which is just enough in winter when not living in house, garage is integral not heated but clearly does get some heat from house, as when at home a single 8W CFL bulb is enough.

The fridge also sensor under sponge, the heater is a demo under floor heating tile which draws 18 watt, good in that it heats from bottom of fermenter, but really has too much mass, must weigh a kilo so has a tendency to over shoot, although hard to tell if due to fermenting or heating tile too heavy.

The reason for transfer is one, frees the freezer for next brew, two it gives a good head to syphon, so normal is around 7 days in freezer then one day in fridge to settle, then rack into clean fermenter and another 7 days in fridge before bottling, freezer normally set to 19°C and fridge to 23°C bottle into plastic bottles. This means if I make an error and bottle too early I can test without opening bottle, also quicker to fill 12 pop bottles than 40 one pint bottles.

Since the fridge/freezer is old, I know at some point it will need replacing, as a result kept an open mind to other methods, one point is freezer is frost free, which means when the motor is running there is a fan circulating the air, so cools the fermenter faster, and also there is no cold stored in the unit, so once it switches off temperature does start to rise. If I was using a chest freezer I would likely get different results.

So looked at the idea of either a Peltier unit, you can get them with pumps to circulate cold water, however the efficiency is very low, so it would need to be large and at 12 volt DC power supply is a problem, so then looked at the 32 litre freezer I have, remove door fit a tank with water and circulate that cold water, but then comes the question will tap water cool it enough, and answer is likely yes, so a tub with water and disinfectant mix and pump connected to thermostat seems likely the best option, you can drop in ice either direct or a frozen pop bottle to cool water cistern and because using a pump it will only use as and when required, that does seem the cheap option.

However that is a lot of messing around, so decided to wait until the fridge/freezer fails then select how to cool. But 24°C to 19°C was between 1/2 and 1 hour motor running, at 60W so looking at 0.045 kWh to cool to start with and around 0.1 kWh in total, sad me used a energy meter, 360 joules in a Wh so 36 joules, so a single 2 litre bottle of frozen water will likely keep it cool enough for day one.

Big question do we really need to control cooling, or would putting a frozen 2 litre bottle in with the fermenter on day one be good enough? i.e. just control heating and place a pop bottle in a towel to reduce transfer speed and cross fingers. I was all set to test, however moving away from home stopped it. I did however put some 2 litre pop bottles in freezer ready, it took days to freeze, so you would likely need to be freezing two or three bottles, by day three it really does not matter if temperature raises so it seems to be a reasonable method and cheap.

Although I have some remote temperature sensors which can be computer monitored so draw a graph to show the result, the fridge is an effective Faraday cage, so they will not work, so I need to visit once an hour and manually monitor.

So it again comes to is it worth it, or just get another brewing fridge?

 

[Bigcol49]

Hi!
1. Frost-free freezers have a heater that kicks in to warm the air to prevent frosting - not good for temperature control.
2. Isn't it defeating the object to have two sensors monitoring the same FV? Just one sensor on the FV is all I use and it works really well.
3. You are obviously far more advanced technically than I am, so sorry for wasting your time.

 

[rats_eyes]

Thanks for the info. Have to see what's happening this weekend as I'll only just be back home from the rig. How many folks attend on average and if bringing some homebrew for feedback how many bottles is a good idea?

Edit: The wife says that I'm free and i should go meet people. So looks like I'll be there on Sunday. :-)

There's usually between 5 and 15 people, so quite variable. I take along 660ml or a litre of a brew, this usually makes it all the way around the table. There can be a lot to go around some months, so small tasters are a wise choice! We usually have the double table in the middle of the bar these days, I look forward to seeing you there!
Paul