Bad stir plate - disaster

[krz]

So I bought 2 packs of Whitelabs liquid yeast ($22) and prepared the yeast starter and in went the yeast.
Put the flask on my keg king stir plate and shortly there after went to bed.

In the morning, woke wondering whats that stench!
Found the yeast starter was boiling, somehow I accidentally hit the hot plate switch.
The light was defective and I ruined the yeast.

Just wondering what I should do to ensure this never happens again.
Not only was the yeast "toast" but it was also probably dangerous.

I'm thinking of either opening up the machine and disconnecting the wire from the hot plate, but then again I might want to use the hot plate function. Then I thought, I wonder if I could convert this hot plate into a temperature controlled hotplate with say another stc1000 controller.

What do you guys reckon?

 

[Ben Davies]

Shoit lucky fella that sux sorry to hear man!
Ive got a DIY stir plate so no heat function.
If your in the south of Aus then keeping the heat function may be good. For an STC hook up youd still need to wire into the heat function on your stir plate i think- that way your not switching the whole unit on and off as the temp relay switches in and out?

 

[shmang]

You could try installing a thermal switch inside the stir plate that will cut the power to the element if it gets above say 20°C.
Depends on how much room is inside the stir plate.

 

[Danscraftbeer]

Um. My home made stir plate. No heating!
I say again. No heating! Repeat, No heating! Other than putting it into the temp control fridge, or not!

 

[Rocker1986]

There's nothing wrong with a heated stir plate if it has control in it to switch off the heating once it reaches a certain set temperature. I have one myself and it's ******* brilliant over the cooler months. I simply put the temp probe on the flask under some foam, set the temperature to 24 or whatever and let it go. It just keeps it at a nice temp when the ambient drops. No need to be using brew fridges or whatever, which would be useless for me anyway because every time I'm making a yeast starter the brew fridge is sitting at 0 degrees cold crashing the last batch

Why the hell anyone would design and/or sell a heated stir plate specifically for growing yeast starters and not bother to put any control in it to stop this exact thing from happening though, beats the living **** out of me. Stupidity at its finest.

 

[Schikitar]

I felt a great disturbance in the Force, as if millions of yeast suddenly cried out in terror and were suddenly silenced.

 

[krz]

T...

Why the hell anyone would design and/or sell a heated stir plate specifically for growing yeast starters and not bother to put any control in it to stop this exact thing from happening though, beats the living **** out of me. Stupidity at its finest.

Tend to agree with you, its an awful design.

 

[Rocker1986]

Probably designed for scientific labs where the solutions are boiled or heated to high temps. Unfortunately doesn't work well for growing yeast [emoji23]

 

[Quokka42]

The problem with even a high quality stir plate is that it is not monitoring the temperature of the actual wort. If the stir plate has temperature control, you can build a small insulated box to keep it in, but still you should set the temperature about 4 degrees lower than what you are aiming for (30 for ale, 24 for lager.) I have built a little temp controlled box for mine - controlling the ambient is very effective, but I still find the wort tends to be a little warmer.

 

[Rocker1986]

Mine has a temp probe that I stick to the side of the flask underneath some foam, not unlike the way I use the temp controller on my brew fridge when fermenting full batches. I don't need heating very much up here but usually a couple of batches a year. It works well enough doing that.

 

[Rocker1986]

Mine has a temp probe that I stick to the side of the flask underneath some foam, not unlike the way I use the temp controller on my brew fridge when fermenting full batches. I don't need heating very much up here but usually a couple of batches a year. It works well enough doing that.

 

[krz]

Mine has a temp probe that I stick to the side of the flask underneath some foam, not unlike the way I use the temp controller on my brew fridge when fermenting full batches. I don't need heating very much up here but usually a couple of batches a year. It works well enough doing that.

Thats what I might do, I might buy another temp controller and use that. Keep the yeast mix at pitching temp

 

[Rocker1986]

You'll have to work out a way of making it only turn the heating function on off rather than the whole unit, otherwise you'll be stop starting the stirring itself. You ideally want it higher than pitch temp, I usually run them in the mid 20s.

Mine came with the probe already fitted, although I had to fix it last weekend because the pin end was loose in its socket and I couldn't set the temperature. Then something else came loose when I was putting it back together and I think it stopped the heating from working. The starter on it still fermented though.

 

[RobinW]

I made a stir plate out of a plastic box, a computer fan and a voltage regulator.
I stick it in the fridge in summer but this time of year it just takes longer to finish.
But that's Queensland for ya. Perfect one day, beer the next
I'm guessing consistantly cold weather is a PITA.

 

[Quokka42]

Kelsey might remember a rather technical report I shared, either here or on another forum, that shows that starters work quite well if stirred and warm. The usual upper limit is 30C because it is the point at which bacteria tend to get an advantage, but a nice stable temperature is more important - preferably in the 20-30 range for ales, 16-25 for lagers.
I have had great success just by building a little insulated box for my starters when there isn't a fermentation chamber with room to spare to suit.
The yeast I use for washes produces enough heat that if I start it in the mid 30's it will maintain appropriate temperature in a Melbourne winter - in fact I usually pitch it into a warm (35+) wash and leave it in a Wine fridge with the power off. New PCBs should be here to keep it up soon, but it's working.

 

[Rocker1986]

I'm in Queensland as well, in summer I just leave them on the kitchen bench at room temperature. But as I said before, the brew fridge is always cold crashing a batch whenever I'm making a starter so it wouldn't do much good anyway [emoji12]