Stc-1000+

[Bigdaddyale]

I was successful purchasing 2 STC-1000 that were v1.0 from this Amazon seller on August 23rd (Seller is "City Digital" in case it doesn't carry through on the URL):
http://www.amazon.com/dp/B008KVCPH2/?tag=skimlinks_replacement-20

I don't know if it'll continue to work, but it was worth the risk for my needs, and it paid off.

I just received 2 more units today.total of 4 with ver 1.0

 

[wilconrad]

Hi,

just received the wrong version (from eBay seller mixtea). It is labelled 20140528 FR-4, micro controller is HOLTEK HT66F40, see attached photos.

Is this version compatible in any way?

Cheers.

Interesting. This is the first "unflashable" version I've seen with the power & sensor terminals close together. Looks like that check is no longer legit. Crazy how many versions of this thing we've come across so far!


Sent from my iPhone using Home Brew

 

[Spellman]

I'm kind of a novice at this, but I wounder if someone could point me in the right direction. I'm trying to change a few variables in some of the files, but don't know where to begin on how to make the new arduino files reflect any changes that I make. Reason is I'm trying to increase the hysteresis for my glycol chiller, and would like to try my hand at making the changes myself. Can anyone help me with the procedure or link appropriate websites?

On another note about the relays, any idea what the maximum current these will withstand in regards to inrush current? Reason I ask is my chiller uses a 5000 btu ac, with a current draw of something like 4-6 amps, but the start up has a spike of about 22 amps near as I can tell, my kill-a-watt isn't quite quick enough to register it, but from what I can find on the net this seems to be what they can draw when they fire up. Any idea on how this would affect the longevity of the internal relay? Just to be on the safe side I ordered a contactor to take the load, but I guess I'm still curious.

 

[Spellman]

hmm, finally looking through 1.06, am I reading this correctly that you have increased max f temp correction from 5* to 10*? And hysteresis to 10* as well? If I'm reading that right you have just made my day!

 

[alphaomega]

hmm, finally looking through 1.06, am I reading this correctly that you have increased max f temp correction from 5* to 10*? And hysteresis to 10* as well? If I'm reading that right you have just made my day!

Yes, that is correct.

If you are limited by the hysteresis or some other setting that is too restrictive, I'd be glad to make the change and incorporate it.

If you'd still like to get your hands dirty, then it is pretty easy to build your own firmware, as I include a build script that compiles the firmware and includes the hex data in the sketch. You need SDCC and GPUTILS and also make, sed, bash and perhaps some other unix commands as well for this. If you don't run Linux, then a virtual machine with Linux might be the way, but it could possibly be made to work with Cygwin or something similar.

Cheers!

 

[Spellman]

hmm, that sounds like a more trouble than I had originally thought! The 10* changes fit everything for me perfectly now. If someone else was to use a glycol chiller they may or may not desire a few more degrees for that, I'm not really sure as I haven't really used mine much yet. I have the coolant set to 25* with 10* hysteresis and that seems to be pretty close to what others are doing I think. I'll be testing out 1.06 soon, but I don't have a second probe yet, or even know what I would do with one in my setup. I could potentially need one to be placed on the side of my sanke fermenter to prevent undershooting temps. If you are taking requests... I would prefer to have a blank screen when they are soft off, but I remember why you did it and doesn't really affect usage. Would it be possible to have one of the dots on the lcd on if it is in soft off? That might help with people knowing it works and has power, and be a little sleeker than "off." Just a thought. Hard to believe how much smarter you have made these!

 

[fosaisu]

For those in the hunt for a cheap Arduino Uno, I just ordered this one which appears from the pics to be an authentic Arduino, $13.75 fulfilled by Amazon:
http://www.amazon.com/dp/B00MFL3GQW/?tag=skimlinks_replacement-20

 

[alphaomega]

Hi guys!
I'm been planning a few... let's call them changes, because I don't really know yet if you'd consider them improvements yet, for v1.07.

As orangehero mentioned in post #1235, he would like the option to show temperature in 'soft off' mode + he was annoyed at the filter resetting on power on again (due to an actual reset I might add).

This got me thinking yet again about the 'soft off mode' (that I still don't really like, but is a whole lot better now at least). What I am thinking is, that what is the point of the 'off mode'? Well, you want to disengage the output relays (and alarms and what not). I really don't see any reason the temperature couldn't be shown. After all if you want the unit really off, then cut the power. What I am proposing is remove the the 'soft off' junk and instead have an 'off' run mode. That is, the power button will no longer turn off at all, but you'd need to go to 'Set' - 'rn' and select 'off'. This also means you can't do an 'off' then continue to run the profile, you'd need start the profile and jump to where you want to continue from in that case.In this new 'run mode off', temperatures will show as usual, only without thermostat action (relays disengaged). I'm thinking the LED to indicate profile running, could change to on in thermostat mode, flashing in profile mode and off in off mode.

Also, there is no room for any more settings, so I'm thinking of dropping a profile (from 6 to 5).

So far, I guess this does not seem like much improvement at all, but here is the thing. I'm thinking of adding a parameter to the end of each profile, that would dictate the run mode to switch to when the profile ends. I think this could be a really cool thing. That means you could run any profile once this one is done (i.e. loop the profile, or link profiles, or link and loop) or switch to thermostat mode (as is forced now) or switch 'off'.
This makes the firmware a LOT more versatile. And then it can be used outside brewing also. I might even use one to control my electric car engine heater (turn on on weekday mornings, but not on weekends and even have it not turning on if weather is 'warmish').

What do you guys think?

 

[HansEinar]

Great! Even when I thought there was no room for projection you find the road. Soon this gadget can fly us to the moon

 

[alphaomega]

Great! Even when I thought there was no room for projection you find the road. Soon this gadget can fly us to the moon

Had to look it up, but I would say from my quick read that the specs of the AGC is comparable to the the MCU in the STC
Edit: That is, in the same order of magnitude of complexity, clock frequency et.c....

 

[barrooze]

LOVE the new proposals! Can't wait to upgrade to 1.07! Dropping a profile to add the flexibility of linking profiles is awesome. I think the options are awesome. You could have more ramps during ferment for either ale or lager and then just link them to a standard crash cool profile. 2 different ale profiles and 2 different lager profiles with 1 crash cool... I need to add a terminal mount to my box so I can upgrade without opening it up!

 

[adam01]

Regarding removal of the soft off...

What I do with my current thermostat is that before I open the chamber door, I turn off the thermostat (turns off fan, heater, whatever.) After I'm done, I turn it back on. I don't want
the ambient air being pulled into the cabinet while I'm working in there.

Thus, having soft off would be nice. Having to pull the plug is not necessarily easy. Its in back, there are multiple controllers, etc. Pushing the power button is very nice.

Like the chaining of profiles. Power user feature for sure.

 

[fosaisu]

This makes the firmware a LOT more versatile. And then it can be used outside brewing also. I might even use one to control my electric car engine heater (turn on on weekday mornings, but not on weekends and even have it not turning on if weather is 'warmish').

Love it! I'll be waiting for the version where you're running an STC-1000 coffee machine with hot or iced beverages ready in the morning depending on the outside temp.

 

[ClunkClunk]

Speaking of STC-1000+ with other things:

Does the 99 °C maximum temperature still apply? I'd love to use one to control my electric meat smoker's electric heating element, trying to target temps around 225F/107C.

Also, as anyone ever seen a sharp probe sensor for sticking in meat that would work with the STC-1000? I could set a target meat temp as an alternate.

 

[Bigdaddyale]

https://www.homebrewtalk.com/f51/probes-stc-1000-a-337938/
Looks like it would be easy enough to make your own probe

 

[orangehero]

As orangehero mentioned in post #1235, he would like the option to show temperature in 'soft off' mode + he was annoyed at the filter resetting on power on again (due to an actual reset I might add).

The filter reset isn't really an issue, just something I noticed and wasn't sure about. I actually thought something major was wrong at first since the temp display defaults to sensor 2 when you come out of soft off.

This got me thinking yet again about the 'soft off mode' (that I still don't really like, but is a whole lot better now at least). What I am thinking is, that what is the point of the 'off mode'? Well, you want to disengage the output relays (and alarms and what not). I really don't see any reason the temperature couldn't be shown. After all if you want the unit really off, then cut the power. What I am proposing is remove the the 'soft off' junk and instead have an 'off' run mode. That is, the power button will no longer turn off at all, but you'd need to go to 'Set' - 'rn' and select 'off'. This also means you can't do an 'off' then continue to run the profile, you'd need start the profile and jump to where you want to continue from in that case.In this new 'run mode off', temperatures will show as usual, only without thermostat action (relays disengaged). I'm thinking the LED to indicate profile running, could change to on in thermostat mode, flashing in profile mode and off in off mode.

Also, there is no room for any more settings, so I'm thinking of dropping a profile (from 6 to 5).

Can you keep soft off as well as adding SET->RN->OFF? How about my original suggestion of alternate temp display for soft off? For example press POWER quickly to toggle temp display in both on mode and soft off and hold POWER to go between on and soft off.

I would have no problems with one less profile. Even 4 profiles would be sufficient, it's not that difficult to change a profile and takes me less than a minute.

LOVE the new proposals! Can't wait to upgrade to 1.07! Dropping a profile to add the flexibility of linking profiles is awesome. I think the options are awesome. You could have more ramps during ferment for either ale or lager and then just link them to a standard crash cool profile. 2 different ale profiles and 2 different lager profiles with 1 crash cool... I need to add a terminal mount to my box so I can upgrade without opening it up!

What kind of crash cool profile do you use? I just set it to thermostat mode and chill down to 1°C as fast as the fridge can go and keep the fermentor in there until time to transfer. Or you can just add one more step to the profile to crash cool. 9 setpoints per profile is more than enough for me. I don't crash cool by a set schedule though, I go by when the beer is at the proper level of attenuation.

 

[alphaomega]

The filter reset isn't really an issue, just something I noticed and wasn't sure about. I actually thought something major was wrong at first since the temp display defaults to sensor 2 when you come out of soft off.

I'm gonna try and fix both of the issues for v1.07.

Can you keep soft off as well as adding SET->RN->OFF? How about my original suggestion of alternate temp display for soft off? For example press POWER quickly to toggle temp display in both on mode and soft off and hold POWER to go between on and soft off.

The 'soft off' and 'run mode off' are conceptually different. But since the 'soft off' seems to really be something ppl want, I'm gonna try and keep it. It might be confusing to have two off modes, but that is the way it has to be if 'soft off' is going to stay. During soft off temperature cannot be displayed (I looked in to it) as the timer for handling temp and temp control is turned off. During run mode off, it will be displayed though.
I'd like to avoid confusion between the off modes if possible. So I'm thinking maybe changing the names? I like run mode 'off' since it prints nicely on the 7-segment display and says pretty much what it does. Maybe changing the name of soft 'off' to something else? Instead of showing 'off' on the display, I could consider turning display off and only have a LED flash to indicate it's in standby. Hmm... Standby, that could work as a new name? Couldn't it? Any other ideas?

I would have no problems with one less profile. Even 4 profiles would be sufficient, it's not that difficult to change a profile and takes me less than a minute.

I'm considering making the profiles shorter now instead. Having 8 setpoints and 7 durations + next run mode setting. That would even allow for 7 profiles currently (but wont add much extra space for new parameters), if more parameters are needed later on then a profile could be dropped then. As you said, 10 setpoints are more than enough in most cases anyway. With linking profiles, then you can overcome the limit of shorter profiles if needed anyway.

All opinions are welcome.

 

[des]

FWIW flashing leds are usually annoying, so I'd stay away from them
Regarding the new-off mode, wouldn't it just be a termometer mode?

What about:
1 power button click -> termometer mode (aka: disengage relays)
1 power button hold -> current soft-mode (I like it better with no off word, but can live with)

Love the chaining, don't mind about shorting profiles, although keep in mind that holding temp with ramping uses 2 setpoint so the get used up faster with ramping enabled. I still think we are ok cutting to 8 sp, specially since chaining will help if you run short

 

[alphaomega]

FWIW flashing leds are usually annoying, so I'd stay away from them
Regarding the new-off mode, wouldn't it just be a termometer mode?

What about:
1 power button click -> termometer mode (aka: disengage relays)
1 power button hold -> current soft-mode (I like it better with no off word, but can live with)

Love the chaining, don't mind about shorting profiles, although keep in mind that holding temp with ramping uses 2 setpoint so the get used up faster with ramping enabled. I still think we are ok cutting to 8 sp, specially since chaining will help if you run short

Usually yes, but it can be more or less annoying. For example 100ms on, 1 sec off on one of the dot-LED's is really not that annoying, but it still shows 'life'.

Yes, it would pretty much be a thermometer. But In terms of regulation it would be regulation = off. I don't think calling it 'thermometer mode' would be the best way to describe the action of the run mode when using it in a profile. Besides there is a 'th' mode which is thermostat mode. How would you show 'thermometer mode' using max 3 7-segment LEDs in a non-ambiguous way?

1 click on power button switches between probes, so I can't use that. And in 'soft off' (or 'standby') temperature reading are not available.

 

[balrog]

FWIW 4, link able, 8 step profiles are more than enough. I have no real opinion of off modes as I am casual brewer and unplug.

But this thing doth rock!


Sent from my iPod touch using Home Brew

 

[des]

Usually yes, but it can be more or less annoying. For example 100ms on, 1 sec off on one of the dot-LED's is really not that annoying, but it still shows 'life'.

I don't have the hardware/setup to test it, so I take your word for it. I do have 2 stc together in my living room so that could be 2 lights every second in a dark room at night. I'm sorry I'm not more helpful than to warn about something potentially annoying without a suggestion on a fix/alternate way to do it.

Yes, it would pretty much be a thermometer. But In terms of regulation it would be regulation = off. I don't think calling it 'thermometer mode' would be the best way to describe the action of the run mode when using it in a profile. Besides there is a 'th' mode which is thermostat mode. How would you show 'thermometer mode' using max 3 7-segment LEDs in a non-ambiguous way?

1 click on power button switches between probes, so I can't use that. And in 'soft off' (or 'standby') temperature reading are not available.

This are 2 very good points, I thought it made sense to use the power button as logically is like you turn off the control first, and then everything...

Maybe use hold vs 3/4 seconds hold? Could that be done easily in your current key handling code? That would resemble ATX soft-off vs hard-off

 

[alphaomega]

I don't have the hardware/setup to test it, so I take your word for it. I do have 2 stc together in my living room so that could be 2 lights every second in a dark room at night. I'm sorry I'm not more helpful than to warn about something potentially annoying without a suggestion on a fix/alternate way to do it.

The blinking LED is just a suggestion, I'm open to other ideas. However, something needs to go on the display. I have my TV in the living room (shocking revelation, I know), it has a red LED that indicates standby. Maybe just light the LED on standby?
Still, if you want it off, you should have a power switch.

This are 2 very good points, I thought it made sense to use the power button as logically is like you turn off the control first, and then everything...

Maybe use hold vs 3/4 seconds hold? Could that be done easily in your current key handling code? That would resemble ATX soft-off vs hard-off

I'm not really sure we are on the same page here.
Short press on pwr button switches between probes, I need a button for that and pwr is the only button that can be used. Long press puts it in standby.
Run mode off can't be put on a button, as there is no way to toggle it, you can only set the run mode, there is no history of previous run mode. Like I said, the off modes are conceptually different.

 

[Singletrack]

...I'm considering making the profiles shorter now instead. Having 8 setpoints and 7 durations + next run mode setting. That would even allow for 7 profiles currently (but wont add much extra space for new parameters), if more parameters are needed later on then a profile could be dropped then. As you said, 10 setpoints are more than enough in most cases anyway. With linking profiles, then you can overcome the limit of shorter profiles if needed anyway.

All opinions are welcome.

I use 9 setpoints, but would modify to 8 for the greater good. The ability to link profiles would be great, though I would prefer not to do that every time. The more complex things are, the more likely I am to screw it up. With 8 setpoints, I would not need to link, so that sounds fine.

I have no preference about run off, soft off, flashing LEDs, etc., except that simple and consistent is usually better... whatever that means. Thanks!

 

[alphaomega]

I use 9 setpoints, but would modify to 8 for the greater good. The ability to link profiles would be great, though I would prefer not to do that every time. The more complex things are, the more likely I am to screw it up. With 8 setpoints, I would not need to link, so that sounds fine.

I have no preference about run off, soft off, flashing LEDs, etc., except that simple and consistent is usually better... whatever that means. Thanks!

Cool! Thanks for the feedback!
And I agree, I will not have the need to link profiles myself either. And I would probably be good with 2 or 3 profiles (ale and lager and possibly one for specialty yeast). But in the words of Yngwie Malmsteen "More is more" Having the the possibility to set next run mode would be pretty neat though as you could do loops or turn off regulation as well.

Yeah, simple and consistent... I like that Simple is pretty much the only doable thing and consistency may be a complex to implement and can be subjective as well. But I'll do my best My personal keywords would be 'reliable' and 'functional'

 

[stpug]

Thinking through possible profiles I would use, I can think of:
-Cool Ale Profile (low 60s F)
-British Ale Profile (ramp 64 to 68 F and back down)
-Cool Lager Profile (mid to high 40s, D-rest, back down)
-Warm Lager Profile (low to mid 50s, D-rest, back down)
-Belgian Warm Profile (ramp high 60s to high 70s)
-Saison Hot profile (ramp mid 70s to about 90)
-Kolsch/Alt profile (high 50s to 60, ramp up, back down)

There may be another couple/few niche profiles I might use depending; e.g. custom single-use profile for specialty beer/yeast. That gets me up to the 7-9 range of profiles. Maintaining that number is preferential in my book.

As for linking profiles, I'm not sure how this would prove useful for me, with the exception of linking a crash cool profile but then I should have enough setpoints to accommodate that per profile. Besides, my lager crash cool would be different than my ale crash cool so I would need two profiles for that.

On the flip side, I would not want to be the reason why a variation didn't see the light of day. I don't know what kind of effort is involved in maintaining "flavors" of the software/firmware, but if it's not too complex then perhaps a "flavoring" of firmwares is in order. For example:
-STC1000+ Standard
-STC1000+ Linking
-STC1000+ Automobile
...and each has it's limitations and features, but works off of the same "base" code. If one becomes too long-in-the-tooth and hasn't proved overly useful then it's featureset is frozen for the foreseeable future.

Just ideas I had, anyway. Thanks for all you've done on this project.

 

[BoulderBayBrewing]

All the parts need for adding a second temp probe on the slow boat from China. Does anybody have any advice on adding the second probe? I've read through this thread and also the readme, so I understand what needs to be done, but am wondering if anyone has any pictures of what they did.

Cheers!

 

[doctorjames]

I've been delighted with the stc1000+ firmware and used it for several brews now. While considering changes to the profile side of stc1000+ though, one suggestion I have is to be able to disable heating and interpolation for individual steps of a profile. This would allow you the option of letting the temperature free rise for a step with the cooling kicking in only if it rose beyond the next set point+hysteresis (which would be several degrees above the starting temperature).

E.g. a profile step that was: start 17°C, free rise to a maximum of 21°C

This might also avoid some problems that can occur with the cooling kicking in during an interpolated rise just because the exothermic fermentation has exceeded the hysteresis amount over the interpolated temeperature value. Depending on the location of the temperature probe this can cause over cooling in regions/layers of the fermenter and curtail yeast activity and prematurely cause dropping.

Cheers
James

 

[alphaomega]

I've been delighted with the stc1000+ firmware and used it for several brews now. While considering changes to the profile side of stc1000+ though, one suggestion I have is to be able to disable heating and interpolation for individual steps of a profile. This would allow you the option of letting the temperature free rise for a step with the cooling kicking in only if it rose beyond the next set point+hysteresis (which would be several degrees above the starting temperature).

E.g. a profile step that was: start 17°C, free rise to a maximum of 21°C

This might also avoid some problems that can occur with the cooling kicking in during an interpolated rise just because the exothermic fermentation has exceeded the hysteresis amount over the interpolated temeperature value. Depending on the location of the temperature probe this can cause over cooling in regions/layers of the fermenter and curtail yeast activity and prematurely cause dropping.

Cheers
James

Thanks for the suggestion!
I understand what you are saying, and while I could see the use for it, there are a couple of issues.
First off, this would add complexity to the profile handling that I'm pretty sure would not be doable with the resources at hand. Secondly, me thinks that the idea of having a profile is that it should be followed. Free rise would depend on ambient, what if it is cold and the temperature doesn't rise, but rather drop? I think the possibility of setting hysteresis for each step should be a better and less complex solution to this, but still, this even this would not be doable without seriously cutting other stuff out.

I would say, use a properly small heater (or no heater if possible) and make the 'free rise step' quickly instead of a long ramp to next step and the rise should be slow anyway.

Cheers!

 

[doctorjames]

Thanks for the suggestion!
I think the possibility of setting hysteresis for each step should be a better and less complex solution to this, but still, this even this would not be doable without seriously cutting other stuff out.

That's fair enough; you've already squeezed considerably more functionality into the device than I would have expected possible! I just thought I'd mention the idea while you are considering modifications to the profiles.

That would be an elegant solution: interpolating a hysteresis and set point per step would be exactly equivalent to interpolating a min and max acceptable temperature per step and so would offer that envelope of control but I quite understand it's likely too complex to squeeze in (though I'd happily give up a profile or two for it!).

Certainly in my case with 50L batches in a typical European tall fridge using a 60W tube heater, worrying too much about the beer/wort temperature is mistaken as there's quite a lot of variation throughout the fermenting beer. Obviously we're only considering and reacting to a reading wherever the probe is, while the convection/conduction of heat etc could vary fom batch to batch despite the probe experiencing a similar profile.

Therefore I've tended not to think of rigidly sticking to a profile but rather wanting to maintain the active fermentation within a safe range, ideally as repeatably as possible, and without causing any unnecessary heating/cooling oscilations etc.

I suspect in my last two batches, a very active fermentation (oxygenated with O2, 1 million cells/ml/°P) produced a lot of heat and got actively cooled, but by the time the probe registered being back at the set point the yeast had started to drop out early. (Though without a log of temperature this is just speculation.)

The probe was in a relatively central thermowell (originally sited where I expected the most active fermentation to be happening, and with the BrewPi algorithm in mind). In my next brew I'm going to move the probe much closer to the lower outer edge of the fermenter (or even tape it to the side) so it responds quicker to heating or cooling which may well solve my issue.

Cheers!

 

[Singletrack]

... Secondly, me thinks that the idea of having a profile is that it should be followed. Free rise would depend on ambient, what if it is cold and the temperature doesn't rise, but rather drop? ...

There's a great point here. I cringe a little every time I hear mention of "free rise." That's nonsensical for me, because my fermenter ambient temps are frequently 40 to 50 F. I think when people say "free rise" they are assuming that ambient is "room" temperature. (The room temperature that I live in varies from 60 to 80 F, so even that is a bit of nonsense, but probably they mean around 70 F.) For the woman fermenting beer in her uncooled attic in Phoenix, Arizona (silly Phoenician), free rise is much different than it is for the guy fermenting on his unheated porch in North Dakota (silly NoDakian). I think we would do home brewers a favor by striking "free rise" from our vocabulary. MANY of us do not ferment in ambient temperatures that are "room" temperature.

So I am not in favor of losing any STC+ functionality to allow "free rise". (No offense to the good Doctor, who understood the issues immediately after Alphaomega's post. And no offense to the good people of Phoenix and North Dakota. )

 

[orangehero]

I don't see how it's nonsensical, it's pretty obvious the conditions in every brewery are going to be different. Just as with recipe formulation you have to make adjustments for your own equipment. If a book mentions free rise, it means exactly that. Maximum temperature is also usually provided.

In any case, it's only in specific cases that a brewery would allow the ferment temperature to free rise, and I imagine is mainly due to convenience and energy savings. If you can control temperature at every time point with precision, such as with the STC-1000+, I don't see why you wouldn't. You can experiment and dial in a flavor profile and then have repeatability without having to worry about ambient.

 

[adam01]

Is there a clean way to separate the display from the relay board ?

My kegerator thermostat is either really picky, or isn't shutting off. So I'm faced with buying a $30 replacement thermostat, or an STC-1000. There is not good place to mount the
thing, but maybe the front display and buttons could be mounted to the door.

 

[orangehero]

Is there a clean way to separate the display from the relay board ?

My kegerator thermostat is either really picky, or isn't shutting off. So I'm faced with buying a $30 replacement thermostat, or an STC-1000. There is not good place to mount the
thing, but maybe the front display and buttons could be mounted to the door.

https://www.homebrewtalk.com/f51/stc-1000-a-464348/index31.html#post6400095

 

[Singletrack]

I don't see how it's nonsensical, it's pretty obvious the conditions in every brewery are going to be different.

Well...that is the nonsense.

If a book mentions free rise, it means exactly that. Maximum temperature is also usually provided.

If your ambient temperature is, say, 32 F, doing "exactly that" may result in cooling your beer instead of allowing the temperature to increase. Listing a maximum temperature does not help.

 

[alphaomega]

Yes. The difficulty is in desoldering the pcb's from each other. Use a vacuum solder sucker to remove as much solder as possible. Then pray you can separate them without breaking anything important.
Replace the soldered connections with a flat cable, optionally with connectors.
The display part will still mount nicely. Mine is held in place by friction, but i guess you could use some silicone or something if needed.

 

[barrooze]

I personally love the idea of a free rise, but then again, I live in the Houston area and 90% of the time my garage (where my ferm chamber is located) is higher than fermentation temps (if not significantly higher). What I've been doing is just unplugging my fermwrap during the free rise portion of my ferment. It seems to work well. I'd love to have the ability for it, but I don't want to rob others of other functionality they may want so I'm ok with forgoing it. Soft off, well... I have a "hard off" on the side of my box that does the trick for me. I would however love to have a thermometer mode while I don't have a fermentation going. On the issue of profile count and setpoint count, if we can link profiles, I'm happy with reducing both the number of profiles and setpoints.

Anyway you cut it, this is the most badass device. Thanks again!

 

[Singletrack]

The alternative to free rise is to control the gradual heating that is desired, and as orangehero pointed out, "If you can control temperature at every time point with precision, such as with the STC-1000+, I don't see why you wouldn't." I agree completely.

If you have a warm ambient temperature and you want to free rise, you simply program your STC+ to ramp from your current temperature to the maximum free rise temperature. If you can get by without heat for this ramp, unplug the heat. If it heats too fast, you may get cooling, but that's what you want. After all, it was heating TOO fast -- faster than you wanted when you programmed the ramp. Personally, I would leave the heat plugged in, so if it doesn't heat fast enough, it will heat it.

I recently brewed a saison that I didn't want to cool during the ramp, so I unplugged the cold and left the heat plugged in. This allowed it to ramp up as fast and high as it wanted to go, but not slower than I wanted based on my ramp setpoints. If it started to cool, the heat would kick in, so this wasn't really a free rise. Better.

So yeah, the STC+ is awesome. We don't need no stinkin free rise; we have STC+!

 

[alphaomega]

Hehe... Ok, this is turning into a debate on free rise instead
I have no problem with free rise, I can understand that some want to use it. If I could, I would have nothing against adding it. But you really need to pick your battles when it comes to what will fit in the STC.
Still, you can mitigate the issue by using a low power heater. That will allow your temp to eventually get there, but do it slowly. Slow is good, when you are in the correct range.

 

[doctorjames]

I personally love the idea of a free rise, but then again, I live in the Houston area and 90% of the time my garage (where my ferm chamber is located) is higher than fermentation temps (if not significantly higher). What I've been doing is just unplugging my fermwrap during the free rise portion of my ferment.

I suppose you could always put the temperature probe in a tiny glass of water for damping and control the chamber temperature. You don't get any insurance against overshooting the high temperature but you'd get a more consistent environment to experiment with free rising. This would also work for people with the opposite problem of cold ambient temperatures in their garage.

In any case, it's only in specific cases that a brewery would allow the ferment temperature to free rise, and I imagine is mainly due to convenience and energy savings.

It's pretty common in the UK, even in larger microbreweries that export to the US, that cooling takes the form of manually controlled valves that restrict the flow of glycol around cooling coils built into the walls of the fermenters. They use a cold liquor tank held at a controlled low temperature to cool the wort passing through the plate heat exchanger (the used cooling water then refills the HLT for the next brew). The cooling of the fermentation is then relatively gentle and constant, and I suppose simply emulates a lower ambient temperature. The cooling is increased after fermentation to drop the yeast but there's nothing actively responding to the temperature of fermentation.

This isn't just because they're backward or won't spend the money (though this may also be true in quite a few cases ), it's also because that's how many traditional yeast strains work best. Consider for example how Anchor's fermentations take place. That's certainly not convenient! Firestone Walker's approach is also described in the Chris White & Jamil Zainasheff Yeast book where fermentation has 24 hours in cooled conical fermenters then is transferred to their union set without further temperature control until primary fermentation finishes then its back to a stainless temperature controlled vessel to cool and drop the yeast etc.

The Yeast book also describes what I think happened to my two previous batches, and would be avoided in a free rise scenario:

Yeast slow down and produce less heat towards the end of fermentation. If your cooling does not adjust for this decrease, the yeast can sense this temperature drop, causing them to slow or stop fermenting. This can result in a higher than anticipated final gravity, along with the yeast failing to clean up some of the intermediary compounds of fermentation.

If you can control temperature at every time point with precision, such as with the STC-1000+, I don't see why you wouldn't. You can experiment and dial in a flavor profile and then have repeatability without having to worry about ambient.

Please don't think I'm picking on you individually but you articulated here a very attractive and intuitive concept so it's useful to quote! Of course we all want things to be repeatable but it's certainly no criticism of the STC-1000+ firmware when I say that we're assuming too much consistency within the fermenter if we believe that this temperature control will provide that level of precision. Presumably what we're most concerned with is the temperature range experienced by the most active yeast cells. I mentioned convection in my previous post. If you have library access to Brewing: Science and Practice by D E Briggs, P A Brookes, R Stevens, and C A Boulton then (apart from generally being a great source of information) page 538 has a really interesting discussion of the challenges of uniform temperature distribution even in state of the art commercial fermenters:

… it is clear that the natural convection currents are inadequate to provide totally uniform cooling irrespective of the position of the cooling jackets on the vessel or the nature of the coolant used. Beer in the upper volume of a tank may hardly change its temperature throughout a cooling regime. Temperature probes in the lower zones of the tank may indicate that temperature control is being achieved but this is often not the case for all the beer in the tank.

If your fermenter is accessible during fermentation, you can verify this yourself if you have a suitable length thermometer or thermowell. This is of course the fuel of the endless debates elsewhere on this forum and others about correct temperature probe placement (actual answer: what works best is actually a side effect of the combination of the algorithm of the controller and dynamics of the specific system).

If you want to disappear down a rabbit hole reading about the behaviour of the cooled film of liquid on the inside walls of the fermenter, then the inversion temperature is particularly interesting: water at 4°C is most dense; water both over and under this temperature will rise above it (again discussed in Brewing: Science and Practice if you're interested). An interesting idea it talks about is only cooling one side of a fermenter in areas where this inversion happens to encourage lateral convection. I wonder if adding some insulation on one side of the fermenter would have any useful effect at our scale?

I have no doubt the STC1000+ is helping achieve the improved consistency we all seek but it's healthy to remember in such a complex dynamic system there are more variables that will affect the temperature the yeast experience from batch to batch than just the controller profile (probe placement, heater size, heater lag, chamber size, chamber insulation, other chamber occupants, outside ambient temperature, outside ambient temperature range, initial wort temperature, fermenter material, fermenter shape, batch volume, oxygenation, yeast nutrient availablity, viable yeast cells pitched, yeast generation, yeast strain, and so on…). For me the goal is to minimise the variability in results stemming from these factors rather than to think in absolutes, and to remember that sometimes prodding and poking a complex system makes it less predictable!

Hehe... Ok, this is turning into a debate on free rise instead
I have no problem with free rise, I can understand that some want to use it. If I could, I would have nothing against adding it. But you really need to pick your battles when it comes to what will fit in the STC.

Haha, yes, I didn't expect this to prove so controversial! I think this longer-than-intended post completes my input into that particular debate

Have you (or anyone else) experimented with the second probe much? That may well address some of my concerns too (I've not fitted one yet).

 

[Spellman]

doctorjames you raise some very valid points! I would like to add though that this may not be as off topic as it first seems, as knowing how to correctly use the stc-1000+ effectively and efficiently is as important as anything. I for one went from no fermentation control to glycol jacketed sanke kegs and really enjoy it. It leaves out some of the inconsistencies that can arise from a chamber and ramping temps. Right now I use a thermowell that runs into the center, but I'm guessing that if it were slightly closer to the sides it would improve any over or undershoots (right now .3*, yeah yeah relative to the 1* accuracy of the temp sensor ). I haven't done the same amount of research that doctorjames has done, but I would speculate at the scale that we are doing the temperature stratification would lessen considerably. I'm would also imagine it would lessen even more if one were to pump the glycol through a coil in the wort as some are starting to do with their conicals. Cold wort would fall downward, warm would rise and meet the coil, and so on. As for the yeast getting cold at the end of fermentation, they are lazy sob's when they are almost done and don't respond well to downward temps, which is why I have been using the ramping feature to gradually ramp up to the higher temp range of the particular yeast to make them finish out quicker. Before I would always come in a few points short of where BeerSmith would estimate my FG would be, now I hit it dead on.

As for the free rise debate, obviously you can experiment with what you want, but I like controlling the entire process precisely as much as possible. That isn't to say I haven't had instances where the beer was done but I wasn't ready for it. I just disengaged both relays and let it sit in limbo in my 65* basement until I had time to deal with it. When I designed my fermentation panel I put indicator lights for heating and cooling (I just glance into the room where I ferment and can tell what it is doing from a distance), and manual on/off switches for heating and cooling. That would be an easy cheap solution for a scenario where you want cooling but no heating or vise versa. Switch them both off and you have temp only. Now if I had only thought ahead to put switches for the units themselves I wouldn't be whining about the soft off!