Possibly underpitched? Repitch or dump?

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bradlewa

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I do 3 gallon batches using BIAB. This is my third or fourth time using this setup, and this batch is a Kolsch with an OG of 1.055. Everything went fine up front with the mash and boil. I'm using Wyeast 2565 for this batch, and I activated the smack pack and had it swell over the course of the brew day. I pitched the yeast last night, and everything seemed fine, but this morning there is no sign of fermentation - no bubbling, no beginning of a krausen, etc.

So I went back after the fact and looked at the Wyeast package, and it apparently was manufactured back in Sept, so using one of the online calculators, is only 25% viable.

Previously, with fresher yeast, I've been ok going right from a smack pack into my 3 gallon batches of IPAs (using 1056). But with this yeast, I probably needed a starter and it's underpitched.

So my question is - can I go back and add more yeast to it now (24-48 hours later), or is this batch likely doomed, and I should just toss it. If I'm at high risk for serious infection/oxidation/off flavors by repitching, then I'd rather save the money I'd be spending on another yeast pack.
 
I see no problem with re-pitching at this point. But... you might also give it some time. If the pack swelled after you smacked it, then that's an indication that you do have viable yeast. Also, not sure what your fermentation temp is, but if happens to be on the lower to mid point of the range, you may want to bump it up a bit.

Good luck!
 
The batch is definitely not doomed. When you pitch fewer cells they take longer to replicate before they get to work. That is why you don't see activity yet, they are still budding to make more cells. You will have more ester production than normal in this batch, but who knows, you might even prefer the flavor! Don't dump it, let it ride and see how it turns out.

Out of curiosity, how did you oxygenate, and did you add any yeast nutrient?
 
I agree with StLou, give it another day. I repitch slurry and after hitting it with pure o2 I still get long lag times-not necessarily a bad thing, just yeast preparing for the feast. Good luck.
 
3 gallons?
I would get another, hopefully fresher, 2565, smack it, wait 3 hours and pitch it. That is if you can buy it locally.

What temperature are you fermenting at? Best is about 60°F or a bit lower.
 
I think at this point what's done is done. The pitched yeast is growing during the lag phase, so you should have plenty of yeast by now. Have you taken a gravity reading? Signs of fermentation?

The yeast throw off different flavor compounds during the lag phase, which might give you some off flavors. Pitching more yeast now won't correct that, and time may or may not help. Probably not help.

The best practice is to always make a starter, regardless of viability. If you don't like making starters, either always pitch two or more packets, or use dry yeast.
 
Went with Kolsch specifically for this batch because I knew I'd be dealing with colder temperatures, and because I wanted to try something new. Cooled the wort down to 62oF, and it's sitting at ~63-64 right now, so I'm in the range for this strain.

I aerated by dumping the wort through a strainer into a plastic bucket to remove some trub. Then let that settle a little before siphoning through another strainer into my glass carboy. Shook/swirled this around a bit before pitching. Not the perfect way to aerate, but it's what I've done with my previous half dozen bathes, and they have all started fermentation much more quickly (but have always been at higher temperatures...likely too high for some of them). This is my first batch I'm fermenting at a lower temp (for my standards), so it's possible I'm just being impatient.

Did not add yeast nutrient. Probably should work that into my SOP. People normally add this to the boil at like 15 minutes remaining right?

I can go to my LHBS and get another pack, but it would be the same lot and manufacturing date. If I was going to use it, I'd probably setup a starter and pitch tomorrow, which would be 48 hours post initial pitching.

So consensus seems to be to wait it out...but I could repitch. Downsides to repitching? Off flavors? Or are there really no downsides at this point?

Thanks for the help guys!
 
Let it ride at this point. All I can do is restate what schokie said, it is right on.
 
No signs of fermentation yet....so I haven't taken a subsequent gravity reading. I'll give it some time and report back.

Point taken though about the starter. Thought I could get away without it with the 3 gallon batch...had I looked at the packaging date on the yeast, I definitely would have set one up though. Lesson learned.
 
I aerated by dumping the wort through a strainer into a plastic bucket to remove some trub. Then let that settle a little before siphoning through another strainer into my glass carboy. Shook/swirled this around a bit before pitching.

That's how I aerate as well. I agree it's not the best way, but it's the cheapest and it's worked for me so far. That being said, an actual aeration system is on my short list for purchase.

Did not add yeast nutrient. Probably should work that into my SOP. People normally add this to the boil at like 15 minutes remaining right?

Yup. I put 1/4 tsp DAP into each boil at that point. 10-15 min or so left, whenever I do my late additions.

I can go to my LHBS and get another pack, but it would be the same lot and manufacturing date.

Your LHBS is selling old yeast? Have you called or spoken to them about that. I'd honestly ask for your money back. They should have either sold that or taken it off the shelf a long time ago. If all you're going to get from them is old products, I'd save your money and buy online. With temps this time of year you shouldn't have to worry about damage to the yeast during shipment.

So consensus seems to be to wait it out...but I could repitch. Downsides to repitching? Off flavors? Or are there really no downsides at this point?

There aren't any downsides other than the money. You don't stand to gain much, so it's probably best to save your money. But if you really, really want to , it won't hurt anything.
 
Even with a full pitch, you wouldn't get much of a gravity change in 12-15 hours - mostly the yeast is in growth phase. For a 3 gallon batch, a smack pack is just about OK for pitch rate (though maybe for a lager you want a bit more.)
IN general, I wouldn't really worry about it quite yet. If you get to 72 hours without any activity, you may want to consider a repitch, but as long as your sanitation is up to snuff, you shouldn't have to worry about infections.
 
Just giving an update here. About 24 hours post-pitch, I saw there was some activity in the airlock. Woke up this morning (~36 hours post-pitch) and had a nice krausen formed with constant bubbling in the airlock (maybe one bubble per 1-2 seconds). So, as suggested, I just needed to wait a bit for the yeast to grow. Looks like I'm in business now without having to repitch.

Thanks for the helpful suggestions on this one!
 
That German ale yeast has scared me with its long lag time too. It's kind of a hybrid yeast.
Think about it this way, you just made a huge starter for the next batch!
 
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