Fermenting temperature

[MarkF_2703]

Hi all,

I have just picked up a Courage Best Bitter kit, I tried this one in the Winter, but wasn't very impressed, but now I have a fermenting fridge I thought I would give it another go as I have more control over the temperature, also first time I used Sainsbury's Highland bottled water which is quite soft I believe.

Living only a few miles away from the site of the old Courage brewery, and sparked up reading water quality discussions on various forums, I thought it cannot be a bad idea to use my tap water, surely that's got to be a similar mineral make up as the original Courage Best bitter which was drawn from a bore hole on site I believe, in any case my water is very hard. Half a crushed campden tablet sat in 20 litres of tap water over night.

I digress, so the instructions on the kit stipulate 18-20 degrees room temperature, which got me over thinking again, my inkbird thermometer is in a bubble wrap pocket on the side of the fermenter to measure the wort temp rather than fridge temp. If the instructions state room temp should I just measure the temp of the air in the fridge? Also which is best 18 or 20 degrees or just plump for 19?

Told you I was over thinking it, but I would love to get a good brew this time, it was the beer I was brought up

[McMullan]

Try to keep the wort at 18-20*C during active fermentation. Ignore ambient temperature. The fermenting wort will be way above that.

[Fil]

aye yer overthinking it.. generally as a rule of thumb its expedient to ferment at the lower end of any range provided for a strain of yeast.
18-20 however is quite a narrow range.. so i would suggest if in any doubt start with a target of 18 and see how it goes. there should also be some setting relevant to how far off the target either input will be switched.. If maintaining a stable temp its ok to set this quite narrow, but if changing the bulk temp significantly set it wider to avoid the 2 inputs chasing each other..

For the water i would try tap water (treated with a campden tab) 1st off then if not quite right perhaps a mix with tap and bottled 75:25 or 60:40 perhaps? again generally a harder water is better suited to a bitter or darker heavier beer and softer water for the lighter beers..

brew, taste, and refine

[MarkF_2703]

Thank you, will control the wort temp rather than the air temp, I was just considering that the suppliers had taken into account the rise in wort temp due to fermentation, but I guess at 18 degrees it will get done, eventually.

I have been doing kits with bottled water for a couple of years now, but I keep adding equipment so that is having more of an effect than the water ATM just wanted to try Courage bitter brewed with Reading water Planning on AG later this year, now after three years I know I can keep at it and its not just "another" hobby, garage is full of them.

[Mr Squiffy]

You don't need to worry about your water with a kit, the mash is where water treatment maybe necessary. With a kit the mash process has already been done.
Use a Camden tablet and that's all you'll need, just crush and add to your tap water.

[HTH1975]

I know that the general consensus is that water isn't as important with a kit brew. I'm not so sure myself - water certainly has its own taste when comparing different sources (try out your own comparisons, I did).

The mineral content of the water will still affect the fermentation process, so my view is that water treatment is still important for kit/extract brews.

[MTW]

I agree to keep it at the low end of the range given, at least for the first three days or so.

You're doing the right things adding campden and using the bubble wrap to the side of the fv.

Water does have it's own taste/qualities, but as long as there's enough calcium in it for a good fermentation, I wouldn't worry personally after that for a kit brew. As for the calcium, I certainly want a bare minimum of 50ppm, ideally 100 or so. I certainly wouldn't start diluting with soft bottled water to a level that reduced it below that, in the search for any particular profile, with a kit.

Edit... Just to say that we don't know what minerals we are getting in the kit anyway, at least not in any I ever saw.

[MarkF_2703]

Good stuff, thanks all, my water report for 2016 gives a Hardness (Total) as CaCO3 of 293 mg/l

[McMullan]

What you might want to consider at some point is fitting a thermowell to your FV. Then the temperature sensor detects wort temperature. Until then, I'd recommend setting the fridge temp to about 16*C during active primary fermentation, typically days 2 to 3.

[MTW]

In a simple fermenting fridge set up, I wouldn't ignore the ambient (fridge) temperature. You are using the air to cool/heat the wort, and it takes a while for that to transfer to the whole mass, in each particular heating/cooling phase. Measuring only the temperature deep inside the wort may be useful in a multi sensor setup and in any situation where there will be less lag in the method of heating/cooling. I have found a couple of layers of bubble wrap over the probe halfway up the wort on a plastic FV to be pretty damn accurate, allowing muted contact with both the air and the wort. Certainly accurate enough not to be shooting 2C lower IMHO, though I would concur that I'd rather be slightly under than over, with many yeast strains, if there's any doubt.

[McMullan]

I used to think that too, MTW. The yeast (CO2 they produce mainly) seem to mix the wort sufficiently during active primary to keep the wort temperature fairly evenly distributed. It's incredible how much heat gets generated by vigorous primary fermentation. Plastic (all my FVs are thick plastic) is a poor conductor of heat. If using fridge 'ambient' or outer wall of an FV, I'd recommend monitoring wort temperature to get an idea how much higher the temperature can be inside the FV.

[MTW]

I do, with a thermapen, and it's always within 0.5C at the top centre, however vigorous. I appreciate there will be a slight vertical gradient. I find it works well for me, but everyone's setup will vary and I would agree to edge on the low side if in doubt.

[MarkF_2703]

Thanks all, one thing I have found reading the forums is that there is more than one way to brew Cwtch kegged and Courage BB in the fermenter and fridge cooling from the 28 degree wort mix prior to a thoroughly good stir and pitching, I will go for the bubble wrap approach for now, got to be better than the last time which was in the fermenter in the back room at the mercy of the central heating.

[MarkF_2703]

Oh boy, still cooling, but opened the fridge and the malty waft is just the same smell as I remember from the brewery in the 80's when the wind was in the right direction at work.

[Kev888]

A bit late to the party, but FWIW: As mentioned above, it is the fermenting beer that needs to be kept at the desired temperature, not the surrounding air. For many/most people, this means that a probe measuring the wort via a thermowell or heavily insulated contact with the FV wall is the best choice.

However, in some cases there are practical reasons for not completely ignoring fridge temperature, depending on how things are set up. For example, with a big batch the fridge can run for too long, overheating the compressor as the wort sluggishly changes, or if the heater is unnecessarily powerful then the fridge may get dangerously hot before the probe in the wort notices. If these are of concern then a compromise (such as the bubble-wrap) may be worthwhile for safety reasons.

If your controller is low resolution, that too could possibly favour measuring the air. This will result in much smaller temperature swings (so better stability) of the fermenting beer, BUT absolute accuracy would also be reduced so you'd have to adjust manually to compensate for the slower changes due to the fermentation self heating. Or again, compromise with a bubble-wrap like approach. However, most modern electronic controllers don't fall into this category.

Good luck with it, temperature control is a very worthwhile thing.