Homebrew

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gregorach

Bushcrafter (boy, I've got a lot to say!)
Sep 15, 2005
3,723
28
50
Edinburgh
For fermentation? I'd tend to disagree. +/-1 is pretty good Don't be chumped by any of those controller's claims of +/-0.2 in practice they will never achieve anything approaching this.
By the way, before I was selling bushcraft gear I had a firm making temperature sensing probes so I know there's an industry wide fog regarding temperature accuracy of systems.

Well, there's accuracy and there's accuracy... I certainly don't imagine that any of my thermometers are particularly accurate in the absolute sense (my best instrument in that regard would be my ETI Thermo 20, which is calibrated to UKAS standards and claims an absolute accuracy of +/- 0.4 deg C - it's slightly overdue for recalibration though) but they mostly seem to have pretty good repeatability, which is what really matters. And I also don't imagine that the entire vessel is at exactly the same temperature... I'd settle for +/- 0.5 degrees. Mind you, I'm a bit obsessive...

Just out of interest, what is the optimum temperature for a good ferment?

Depends a great deal on the yeast strain and beer style.
 

Lurch

Native
Aug 9, 2004
1,879
8
52
Cumberland
www.lakelandbushcraft.co.uk
Generally speaking to get anywhere near that kind of accuracy/stability at close to ambient (as most ferments tend to be) you need a stirred vessel and a cooler as well as a heater. Without those two extras you'll be doing well to acheive +/- 1 never mind 1/2
A lot of temperature control instruments are damped so you don't see the full extent of the temperature fluctuations. Cheating a bit you might say.
 

gregorach

Bushcrafter (boy, I've got a lot to say!)
Sep 15, 2005
3,723
28
50
Edinburgh
Well, I do have a cooler - chilled water recirculated through a coil on the outside of the fermentor. But yeah, stratification is still likely to be a bit of an issue (although it's only 25L, so less so that in a larger, more vertical fermentor). Still, switching to a controller with a tighter range should mean that the heater / cooler runs more often, which should at least drive some convection currents. I'm currently thinking about the Forttex TC-10, which I've heard pretty good reports about.
 

gregorach

Bushcrafter (boy, I've got a lot to say!)
Sep 15, 2005
3,723
28
50
Edinburgh
That unit will just give you regular over/under run if you try to set it too tight.

Yup - by about 0.2 degrees according to my ACT800. So no point trying to get it down to any less than that... Which is why I say I'll settle for +/- 0.5.

Why not go for a PID?

'Cos I just haven't gotten that sophisticated yet. It's probably coming though, sooner or later... The current project is oxygenation with bottled O2 (just waiting on a flowmeter), then the counterflow chiller (which will involve getting a bit creative with the plumbing due to space restrictions), and after that it's probably the shiny mash tun and switching to fly-sparging rather than batch-sparging. You know how things stack up... ;)
 

Samon

Bushcrafter (boy, I've got a lot to say!)
Mar 24, 2011
3,970
44
Britannia!
yo guys! right, i made a **** easy batch of ginger beer the other week, tasted lush and im guessing was about 4-5%.
Ok, i've brewed wine in the past and was never fond of the outcome or fermentation time..so i gave beers a go and found sweet/fruity beers the best for quick and satisfying results.4 litres of Ginger beer and instructions are as follows!.....

1.hand sized lump of fresh ginger.
2.2 cups of white sugar.
3.2 lemons.
4.1 teaspoon of champagne yeast.
5.4 tablespoons of honey.
6.2..2litre bottles (sterilised)

start off with grating the ginger witha cheese grater and stuffing it in your bottles equally, then pour your 2 cups of sugar between thbe two bottles. cut and squeeze hlaf a lemon in each bottle. add your two table spoons of honey to each bottle(hot water and funnel help alot) then add half a teaspoon of your yeast and top off about 4 inches under the cap with warm water then shake. remember, leave the cap on! and in two days your ginger brew will be ready, but...make sure to release the pressure every 4 hours or so as it really does brew fast, even leae the caps a tad loose to release the massive pressure naturally. if you do this youll end up with a lovely and fizzy brew. even after a good filtering the fizz will come back as some yeast remains. drink within about a week or itll taste like special brew ;)

i hope someone appreciates this. thanks guys!
 

gregorach

Bushcrafter (boy, I've got a lot to say!)
Sep 15, 2005
3,723
28
50
Edinburgh
<sigh>
I give up.
I'll say this one last time, as a former industry professional in the field of temperature control:
No
No
No
It
Doesn't
That setup is utterly utterly incapable of that kind of stability.

I do hear what you're saying - hence "according to my ACT800". I have no freakin' idea what the reality is. I suppose I could do some sums on the back of an envelop based on the heat input, the thermal mass of the beer and its specific heat capacity... (Although determining the metabolic heat output of the fermentation isn't trivial.) I find it hard to believe that the temperature of 20L of beer is vacillating a huge amount, given the inputs. But hey, I'm more than willing to listen if you're prepared to offer some constructive advice.
 

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