vivarium heat mat

[stevander74]

I have been having trouble with my beer fermentation. The last 3 beer kits Ive done have not fermented as they should. I havent changed my routine or technique with the simple process of kit brewing and i use a good yeast but lately things just arent working properly. Despite living in a centrally heated house i think fluctuating temperatures are whats causing the problem, i think the temps dropping too low at night.
I need a way to regulate the temperature of the wort to allow good fermentation. Heat belts can be expensive and although fish tank immersion heaters can be very effective, being that they can go straight into the wort and are thermostatically controlled, I dont have one. But what i do have is a vivarium heat mat. This is used to give a constant low level heat into a vivarium tank from below for spiders (Im not sure if its the same type used for lizards) so in theory it should do the same for the wort. The problem is it may heat the wort to much so Im running a test to see what happens.
The heat mat i have is 11"x11"(280mmx280mm) and 12watts. I have filled a 5gal FV with water and sat it on top of the heat mat and wrapped it with an old 3.5tog quilt to insulate it.
Does anyone else use anything like this?

Here are the results so far.
The temperature is taken from the middle of the water in the FV.
Started 08/02/11 @ 8.30pm temp 22c. 09/02/11 @ 8am temp 24c. 4hrs later 12pm 25c. 4hrs later 4pm 25c

 

[Sean_Mc]

Last winter I built a fermentation cupboard and heated it with a vivarium heat mat connected to to a bog standard central heating thermostat.
It worked okay, but I hung the mat from a side wall, I didn't like the idea of the weight of an FV on the mat or risk any vigorous liquid coming in contact with it

 

[BigYin]

the advice I've seen elsewhere involves putting a decent layer of playsand over the heat mat, with wood used to create a stable base for the FV - and the sand allows the heat to spread evenly and avoids hot spots.

I think any heater should be controlled by a thermostat, or at a push, even a timer.

 

[Dunfie]

Here are the results so far.
The temperature is taken from the middle of the water in the FV.
Started 08/02/11 @ 8.30pm temp 22c. 09/02/11 @ 8am temp 24c. 4hrs later 12pm 25c. 4hrs later 4pm 25c

Remember that those temps will be exagerated when the yeast kick off their aerobic respiration. Mike is right in that you need to be able to control the fermentation temperature to get the best out of the yeast.

 

[Deadmonty]

I use a 100 W tropical fish tank heater - a glass tube with a heater and adjustable thermostat. Completely waterproof and easy to sterilise. Cost £9 from Ebay.

 

[vanish]

I use a heatmat and controll it with a TC-10. These are currently housed in a insulated cupboard with the heat pad atteched to the rear wall. I tape the temp probe to the front side of the Fv's so that it's not directly affected by the heat source. This works perfectly.
I have used this set-up in a fridge during the summer, which is also absolutely spot on.
At the moment I am crrently on the hunt for a sutable freezer to put my FV's in, as now that I have moved up to 10 gal' brews the fridge isn't big enough and the insulated cupboard wont do in the summer.
You can get both TC-10 and heat pads from http://www.forttex.com

 

[stevander74]

quick update.
after a couple of days the temp of the water has risen to 28c.
its constantly rising at a rate of 1 degree a day and i dont know where its going to stop. once you take Dunfies advice about busy yeasties into account id say it gets too hot to keep on full time. Maybe just put it on at night to stop it dropping.

 

[timbim]

Get one of these, it will only turn the heater on when the temp drops below the target. Can always use it with a fridge at some point in the future.