Yeast Starter Failure

I have had a 1 litre starter that's been on a stirplate for a little over 48 hours now, and there are still absolutely no signs of activity. When the plate is off the surface is totally still, so I can't imagine there has been any gas production at all. The two smaller steps in the beginning of the week we're normal, and the slant I inoculated in transfer to this vessel had colonies overnight. How long is too long to see a starter take off, and should I just go buy a pack of dry if I'm gonna brew this weekend?

 

Was the stirplate on the whole time? Because it may have fermented out quickly being a later step in a step starter. Your yeast are off and running.

If that is the case, it may have fermented out and finished. Then there would be no CO2 in solution and the yeast would not be active.

 

I've been checking it every few hours and have never seen any gas activity. Is it possible that all of the gas was driven off as fast as it could be produced? I didn't aerate at all before putting it on stir, just boil to fridge to adding the current step

 

I'm not totally sure as I don't have a stirplate (yet!), but I would guess the stirring keeps the starter from accumulating any CO2. It comes out of solution pretty readily if, for example, you shake a bottle of beer.

 

Have you checked the gravity of the starter beer?

 

I turned the plate off a bit ago, hoping to see some sediment in the next couple hours. Im considering a gravity check as a last resort, I would much rather leave the top on until it's ready to pitch if at all possible.

 

^^^ Yes, please check your gravity. And turn the stir plate off and let it settle out for an hour or so. Do you get a nice layer of white yeast at the bottom of your starter?

You very rarely see signs of CO2 production or 'bubbling' activity. Especially because yeast will first multiply, then ferment. If they are multiplying, you won't see gas production.

 

Ok, the stirplate is off and I'm gonna go get the new hydro jar I've been putting off buying. If I've been worrying about nothing and the starter has fermented out, am I good to pitch the hydrometer sample as well? Enough to get a reading will be a meaningful portion of my yeast.

 

Stirplate cultures produce no krausen, and very little (if any) foam. The stirring promotes gas exchange.

With a reliable process, starter wort + stirplate + yeast is hard to screw up and usually grows very fast.

If everything is fully sanitized, pitch your hydro sample as well.

 

Yes, you can pitch that as long as everything's sanitary...but if you're brewing this weekend, you probably should pour back in, cold crash, then decant the oxidized starter 'beer'. No big deal if you can't, but it's a good habit if you have the time, especially with larger starters.

Not seeing any activity after 48 hours sounds suspicious to me. I've always had a krausen like the attached pic on all of my starters... not always a huge one, but you can definitely tell it's there. Did you accidentally pitch the yeast too hot? What was your process after boiling, and do you know the starter OG?

 

Cool it so the yeast settles. That way what is in suspension will be a very small portion of the colony. Not that it would hurt much to pitch it as well.

 

The handful of starters I've made have all had at least a small ring of bubbles around the edges of the vessel while they were active. I'm sure I didn't pitch too hot, I Fridged the new wort at the same time as the earlier step, both were fridge temp when I mixed them. I had planned on cooling and decanting, but I agree that the timing is getting iffy. The plan was to have it in the fridge this morning and good to go for tommorow evening.

 

Wait, the wort was fridge temp when you pitched? If that's the case you might need to give it 24 more hours. But first take a hydrometer reading to know where you're at. Both the yeast and wort should be somewhere around 70* when you pitch, and you should only need to leave on the stir plate for 24 hours or less.

 

Starting from fridge temps (yeast and wort) definitely will slow down the speed of the propagation. It's probably took approximately a day just to get things to room temp where it could get going again. I'll usually pitch my yeast into ~74F starter wort, and active yeast will take off within a couple hours.

I also see something when propagating yeast; either ring of bubbles, krausen, or change of creaminess of starter (on a stirplate). Lately I've had HUGE krausen climbing out of the 2L flask that I have to keep knocking down with a sanitized chop stick (really annoying!).

I suspect your start is fine and just slowly bouncing back from the cold temperatures. Keep it spinning and I don't see any reason you cannot use it for your upcoming batch.

 

I make my yeast starters in 1 gal glass jugs. I put them on the counter and swirl it everytime I walk by. When I swirl, I do get a good amount of foam that quickly settles out. Although technically possible, I would doubt that you could miss it quickly fermenting out if you do indeed check it every couple of hours. There are numerous indicators that are apparent: cloudiness, visible churning, tiny bubbles thin krausen etc. If it completely ferments out these indicators subside but the most obvious evidence, short of taking a gravity reading, is the smell. Take a whiff and it should be significantly different than when you pitched if it is successfully fermenting / fermented.

 

Just checked it again and still no gas release or sediment. It smells similarly to the last step before I put it in the fridge. I think I'm gonna leave it still for another couple hours before I take a gravity reading. If it decides to cooperate I can push back brewing till Sunday to give the yeast a chance to settle out.

 

So I just measured gravity at 1.04, which is definitely not what I wanted to see. I'm gonna give it a little bit longer, but I'm thinking this starter is a loss.

 

What's the temperature at this point? Still cold? If you get it up to 70 and it doesn't go crazy, something happened. You didn't pour boiling water on it, did you?

Seems strange. I thought this was a later step of a step starter. Are you sure the earlier steps fermented?

 

The last step definitely fermented, had a good layer of white yeast at the bottom of the jar. I put it in a room that sits at about 80 yesterday afternoon hoping it was just too cold in my kitchen. How detrimental is it to pitch the entire starter into the beer? I'm hoping for a Belgian character on this one and could grow something up by Sunday, just won't have time to seperate it. Alternatively does anyone know what kind of esters I'll get if I pitch t-58 at 60 ambient and let it warm itself with ferment activity?

Update: Still no activity and no gravity change. At this point it's been idle too long, and open too many times for me to trust it in a full batch. How bad is it to pitch the starter wort with the yeast if I get something else growing for Sunday?