Very weak fermentation

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johnt_mn

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Starting gravity was 1.087. Yesterday it had been three days in the fermenter and no visible signs of activity so I took off the cover and saw a couple inches of krausen but an SG check showed it had only dropped to about 1.083!! Tasted the sample and it was extremely sweet. Today I still see no bubbles coming from the blow-off tube in a bucket of sanitized water.

I'm using an Imperial Stout extract kit from Northern Brewer. Picked up kit from store on Saturday, 9/11. Got two packs of Wyeast 1728, both were marked 50% off because of being only one month until expiration (that's all they had). I only had a jug large enough for one starter, so I made a starter on Saturday using one of the packs. Brewed beer on Monday and pitched the starter plus the other pack. I aerated prior to pitching by stirring and shaking the fermenter for a short period. Wort was on the warm side, about 83 to 85 degrees, room temp since that day has varied between 68 and 72 degrees.

Does it sound like a reasonable plan to check the SG again tomorrow, and if it hasn't changed significantly, hydrate two packs of Safale S-04 and pitch them? Thanks for any suggestions!
 
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johnt_mn

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One possibility is that you have an air leak in the bucket lid (been there, done that) and all is going well. One option is to have a home brew and forget about it for 2 weeks.
Yeah, but I'm surprised that the hydrometer reading has changed so little after 72 hours. But if that's not too uncommon, I guess I could just let it sit for two weeks and then check again.
 

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Have to give it a few more days. Krausen means fermentation. It's possible it got off to a late start and hasn't done much to change the gravity just yet. If it's going, it's going, Not sure I'd dump more yeast in. You wont' harm it, but it probably isn't needed.

Random thoughts:
* As noted, you may have a leak and if so won't notice much activity through an airlock or hose.
* Checking gravity is excellent for monitoring progress. Do be careful in regards to sanitization.
* If you got off to a late start, it's fine, you'll make beer. But you might look at ways to start faster - You probably still underpitched, even with a starter. Something like a 3L starter would have been right and I'm guessing you didn't make it that big. Don't stress it, just consider it for next time.
* Consider the S-04 next time, 2 packets perhaps, skip the starter.

Every brew is a learning experience even after decades of doing it.
 
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johnt_mn

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Have to give it a few more days. Krausen means fermentation. It's possible it got off to a late start and hasn't done much to change the gravity just yet. If it's going, it's going, Not sure I'd dump more yeast in. You wont' harm it, but it probably isn't needed.

Random thoughts:
* As noted, you may have a leak and if so won't notice much activity through an airlock or hose.
* Checking gravity is excellent for monitoring progress. Do be careful in regards to sanitization.
* If you got off to a late start, it's fine, you'll make beer. But you might look at ways to start faster - You probably still underpitched, even with a starter. Something like a 3L starter would have been right and I'm guessing you didn't make it that big. Don't stress it, just consider it for next time.
* Consider the S-04 next time, 2 packets perhaps, skip the starter.

Every brew is a learning experience even after decades of doing it.
Thanks for the ideas, I'll give it more time. I was just a bit worried that the wort might spoil if it sat in there too long without some heavy fermentation taking place. And I think I will use S-04 next time, simpler and cheaper.
 

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You either underpitched or temps of the beer itself are just not what the yeast currently want. Sometimes the fermentation stalls for reasons that we can only guess about.

I never judge activity by the bubbles in the airlock or from the blow off tube. Sure when you have them they look impressive and let you know that something is going on.

I look at the beer in the fermenter. Sometimes with a light to shine through it to see what's happening in the liquid. If you don't have a clear fermenter, you'll just have to wing it.

Removing the lid and opening up your fermenter is definitely not the right thing to do. If you can't see in it then just wait the two weeks or what ever it is normally supposed to take. Then get an SG reading, wait another couple days and get another. If not ready wait another week or better yet 2 weeks and then do the two SG checks again.

Knowing the temp of the beer in the fermenter is useful too. So if you don't have a tilt or temp probe that stays in the beer, then put one on the outside of the fermenter and cover it with some insulation. Then you'll have a slightly better idea of the beer temp than just knowing the ambient air temp.

But don't be willy nilly removing the lid just to see or take a bunch of SG and temp readings. All they will tell you is that you need to be patient.
 
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johnt_mn

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Ok, thanks for the responses. It sounds like having the gravity only drop from 1.087 to 1.083 (4% attenuation) 72 hours after pitching is not terribly unusual and I should just be patient and wait another week or so before checking gravity again. Will do and I'll report back at that time.
 

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How did you oxygenate your wort before pitching the yeast? With higher OG batches, giving it a healthy amount is even more important. When you say 'jug' for the starter, do you mean flask and stirplate or did you just mix up some starter and leave it on the counter for a few days. If so, then that's beyond sub-optimal. Stirplate and flask combination means you can have starters complete in about 24 hours (with reasonably fresh, or under 3 months old, yeast packs). I've had 5-6 month old yeast packs take up to 48 hours (mostly 36) to compete. Without the stirplate in the mix, starters take significantly longer to complete and won't give you as much yeast cells at the end.

I've never seen a batch take three days to move four gravity points. Of course, I add yeast nutrient to my batches (during the boil) and oxygenate with pure O2 as it leaves the plate chiller (before going right into fermenter). Last high(ish) OG batch, at 1.080, took less than 12 hours to get going. That was without a starter but pitching a harvest from a previous brew (a couple of weeks prior).

I highly recommend getting a stirplate and 3L flask to make starters for liquid yeast moving forward. Same with getting an oxygenation setup (avoid the small red O2 bottles and 'regulators' without any actual way to see how much gas is moving) to infuse the wort before you pitch the yeast in. You can also pick up the 'Yeast' book which will give you a lot of information as to how to properly handle the yeast, and what they need to do their best work for us. It's not as difficult, or as simple, as you might think. Doing just a couple of things during the brewing process will make them really shine.
 
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johnt_mn

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How did you oxygenate your wort before pitching the yeast? With higher OG batches, giving it a healthy amount is even more important. When you say 'jug' for the starter, do you mean flask and stirplate or did you just mix up some starter and leave it on the counter for a few days. If so, then that's beyond sub-optimal. Stirplate and flask combination means you can have starters complete in about 24 hours (with reasonably fresh, or under 3 months old, yeast packs). I've had 5-6 month old yeast packs take up to 48 hours (mostly 36) to compete. Without the stirplate in the mix, starters take significantly longer to complete and won't give you as much yeast cells at the end.

I've never seen a batch take three days to move four gravity points. Of course, I add yeast nutrient to my batches (during the boil) and oxygenate with pure O2 as it leaves the plate chiller (before going right into fermenter). Last high(ish) OG batch, at 1.080, took less than 12 hours to get going. That was without a starter but pitching a harvest from a previous brew (a couple of weeks prior).

I highly recommend getting a stirplate and 3L flask to make starters for liquid yeast moving forward. Same with getting an oxygenation setup (avoid the small red O2 bottles and 'regulators' without any actual way to see how much gas is moving) to infuse the wort before you pitch the yeast in. You can also pick up the 'Yeast' book which will give you a lot of information as to how to properly handle the yeast, and what they need to do their best work for us. It's not as difficult, or as simple, as you might think. Doing just a couple of things during the brewing process will make them really shine.
Thanks for the detailed info.

I poured the wort into the fermenter which had a couple gallons of cold water in it, then stirred and shook it around for maybe a minute or two.

For the starter, I used the recipe of 1/2 cup light DME and a half teaspoon of yeast nutrient into one quart of water, boiled for 20 minutes. After cooling in an ice bath, poured it into a growler jug, pitched one packet of yeast, shook it up, then shook it back and forth for a few seconds whenever I walked by for the next 36 hours or so.

It definitely sounds like I under-pitched and under-oxygenated, things I'll fix next time around. Should I add yeast or just wait it out?
 

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At this point, keep an eye on it's progress. The fact that it's dropped 4 points (and sounds like had krausen on the top) means it SHOULD be fermenting. It's just taking off like your grandma after having both hips replaced (the following day). :eek:

Get yourself a stirplate, flask, and some stirbars for the next time you do a starter. You'll know when the starter is done. I use the foam stoppers (from Northern Brewer, since they are the only ones that have the ones that properly fit 3L flasks) to allow easy gas exchange between the starter and atmosphere.

If it hasn't moved any more in another couple of days, you could try adding more yeast. But, at this point, you might just be wasting money and effort. Use it as a learning experience of how important these elements are to a batch actually getting in a good time frame.

BTW, most of my recipes have completed the majority of fermentation within three or four days of it kicking off. So less than five days from pitch. They sometimes creep down another few points over the following few days. Even the old ale, that came in at 8.3% followed that trend.
 

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Agreed to the above. You get credit for thinking about it and trying to get it right. But 5 month old yeast and a 1L starter that used the shake method... Not so bad for 3 - 5 gallons of a Pale Ale that you wanted some esters from, but just not enough for an Imperial Stout.

Brewer's friend has a good yeast calculator, you might put your work into it and see what you got for cell count. And compare some different methods. 3L starter on a stir plate is about right, off the top of my head.

And, yeah, consider dry yeast next time. Don't even have to both with the starter at all. It's what I did on my last Imperial and it doesn't seem to have hurt it at all (I say "seem" because it's only 3 months old and I changed up my recipe from the previous brews, but sips off it so far are quite good and I didn't mess it up w/ an infection or anything else). If you're doing extract, nothing wrong with that, it implies you might not have a ton of time or equipment, and might as well continue to make things easier on yourself with the dry yeast.
 

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I think overall you did a good job with your yeast starter if that was your first attempt. You really followed all of the other Northern Brewer directions pretty well for that beer. Pitching the yeast at 83-85 degrees may have been your biggest mistake in retrospect. Better fermentation temperature control may be the step with the biggest potential improvement. It may have also been easier too to start out with a lower gravity, lower ABV beer till you had the whole process down pat. I bet you end up with a good beer though. Good job.
 

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Two packs of US-05 Dry yeast would have been a better choice. 5 month old yeast has an estimated viability of 5%.

A 1 liter starter without stirring would do a little, but not enough. The pack started with about 5 Billion cells and the starter brought that up to 30 Billion. You added another 5B from the other pack for 35B total. This wort needs about 455B. If I were you, I'd be running out for a couple packs of dry yeast to try to rescue the beer.


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johnt_mn

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Two packs of US-05 Dry yeast would have been a better choice. 5 month old yeast has an estimated viability of 5%.
Wow, I didn't realize the viability dropped that drastically. Would have needed 91 yeast packages 🤣. The brewing store should have been giving them away rather than a paltry 50% off. Good to know for the future.
 
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johnt_mn

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At this point, keep an eye on it's progress. The fact that it's dropped 4 points (and sounds like had krausen on the top) means it SHOULD be fermenting. It's just taking off like your grandma after having both hips replaced (the following day). :eek:
Haha, yes. Grandma's hips must be working a bit better now, at least the blow off tube is actively bubbling now haha. Wow that was a glacially slow start.
 
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johnt_mn

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Agreed to the above. You get credit for thinking about it and trying to get it right. But 5 month old yeast and a 1L starter that used the shake method... Not so bad for 3 - 5 gallons of a Pale Ale that you wanted some esters from, but just not enough for an Imperial Stout.
I think overall you did a good job with your yeast starter if that was your first attempt.
Thanks for the encouragement. I think I'll count this batch as a learning experience and maybe it will be drinkable after all. Next time should be better.
 

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I've always used liquid yeasts. Even when I didn't make a starter (which was when I first started brewing) I would have things go active pretty fast (<24 hours from pitching). IMO, if you're not eating paste, you can handle using liquid yeast. ;) Just don't go all skinflint, buying the 'discount' yeast packs and do a lame starter thinking it will start fermenting quickly (or even in a normal time frame).

My biggest concerns with the batch would be:
Infection due to loooooong lag time.
Off flavors from stressing the yeast.

Also look at the info available for Wyeast 1728 around what it does for different temperature ranges. The impact is not minor.

Room temp is typically several degrees cooler than fermenting beer temp. It's why many of us use glycol chiller setups, or fermentation chambers, to control the temperature of our fermenting beer/product.
 
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johnt_mn

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I've always used liquid yeasts. Even when I didn't make a starter (which was when I first started brewing) I would have things go active pretty fast (<24 hours from pitching). IMO, if you're not eating paste, you can handle using liquid yeast. ;) Just don't go all skinflint, buying the 'discount' yeast packs and do a lame starter thinking it will start fermenting quickly (or even in a normal time frame).

My biggest concerns with the batch would be:
Infection due to loooooong lag time.
Off flavors from stressing the yeast.

Also look at the info available for Wyeast 1728 around what it does for different temperature ranges. The impact is not minor.

Room temp is typically several degrees cooler than fermenting beer temp. It's why many of us use glycol chiller setups, or fermentation chambers, to control the temperature of our fermenting beer/product.
Yeah, I wasn't being a skinflint. I asked the guys at the brew store for some yeast to go with my kit and they came out with the Wyeast marked 50% off. Me being a newbie, I just thought maybe they over-stocked these and wanted to move them out. If I'd known about expiration dates and that my yeast only had 5% viability, I never would have settled for it. Would have been nice if they had informed me.

I'll admit that the starter was pretty lame, live and learn haha. Now the possibility of infection and off flavors will bother me until I taste the final product months from now. Maybe I should dump the whole batch and start over.
 

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I'd keep it, it's already made and fermenting. If you really need room for some other brew, this is a rare time I'd say stick it in a secondary fermenter. If there's a budget, old glass ones are cheap and sometimes free if you live in a decent sized town.

You're right it'll be a while to really taste good, assuming all went well. But you will know pretty quickly, like in a week or less, if you grab a taste during one of your gravity checks if it'll be OK. You might taste some yeast and not exactly call the beer yummy yet, but I think you'll know soon if it's actually "bad". Don't dump it until (if) you make that decision. Beer is funny, sometimes something really small can spoil a batch, and other times you'll be amazed at what you just got away with.
 
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I'd keep it, it's already made and fermenting. If you really need room for some other brew, this is a rare time I'd say stick it in a secondary fermenter. If there's a budget, old glass ones are cheap and sometimes free if you live in a decent sized town.

You're right it'll be a while to really taste good, assuming all went well. But you will know pretty quickly, like in a week or less, if you grab a taste during one of your gravity checks if it'll be OK. You might taste some yeast and not exactly call the beer yummy yet, but I think you'll know soon if it's actually "bad". Don't dump it until (if) you make that decision. Beer is funny, sometimes something really small can spoil a batch, and other times you'll be amazed at what you just got away with.
That's not a bad idea, throw it in a secondary (I've got a plastic carboy) and then brew another batch correctly and compare the two later. Hmmm.
 

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Yeah, I wasn't being a skinflint. I asked the guys at the brew store for some yeast to go with my kit and they came out with the Wyeast marked 50% off. Me being a newbie, I just thought maybe they over-stocked these and wanted to move them out. If I'd known about expiration dates and that my yeast only had 5% viability, I never would have settled for it. Would have been nice if they had informed me.

I'll admit that the starter was pretty lame, live and learn haha. Now the possibility of infection and off flavors will bother me until I taste the final product months from now. Maybe I should dump the whole batch and start over.
I would complain to the owner of the store if you return there. Or shun them (let everyone else know to avoid them due to bad info/practices).

As for moving the batch to secondary. DON'T. If it's in the instructions, remove that part of it. It's a practice that ended many years back. It just means they've NOT updated their instructions in decades (and/or don't give any F's about giving BAD information/instructions).

If you only have one 'fermenter' and want to start another batch, get another one. If you have something the same size, use that as the fermenter.
 
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I measured SG today and it was 1.034, yay! So it dropped 4 points in the first three days and almost 50 points in the following two days. And it tasted really good, no off flavors. Maybe this will finish nicely after all.

Things I've learned for next time:
1. pay close attention to expiration date on yeast
2. use a yeast calculator to figure pitch rate and over-shoot rather than under-shoot
3. if using liquid yeast, make an appropriate starter, possibly using a stir plate
4. get the wort down to a lower temperature before pitching and use plenty of oxygenation
5. be patient :)

Thanks everyone!
 
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hotbeer

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If you can do 5 well enough you don't even have to do 1- 4. except maybe that part about getting the wort down to the proper pitch temp.

Though if you want repeatable results on a particular recipe it helps to control all that and more.
 

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All excellent lessons mentioned above. I made myself a cheat sheet with every step and now constantly update it as I improve each processes. Good notes have helped me to learn from my mistakes and to not repeat them.

Someone above mentioned oxygenation. I use the cheap $10 red oxygen canister from the local hardware store, a small screw on oxygen regulator valve and an aeration stone (both from amazon). With about 30-60 seconds in the wort, I can get about 6" of oxygen foam on the wort. Most of the books I have read show that this creates a significantly higher wort O2 level than simply shaking the fermenter and is fairly inexpensive compared to any fancier set up. I learned that if I only open the valve to the minimal amount to start oxygen flow and then unscrew the regulator from the canister after each use, the canister will last me quite a few brew days. I have never had a bad or slow fermentation with this technique and a good yeast starter.
 
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johnt_mn

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I look at the beer in the fermenter. Sometimes with a light to shine through it to see what's happening in the liquid. If you don't have a clear fermenter, you'll just have to wing it.
I think I'm going to get a clear or at least translucent fermenter. Would be nice to get an idea of what's going on without pulling the cover off.
Someone above mentioned oxygenation. I use the cheap $10 red oxygen canister from the local hardware store, a small screw on oxygen regulator valve and an aeration stone (both from amazon).
Sounds like a great idea.
 

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You can also learn to not give any F's about looking at the beer as it's fermenting. I did that early on. Been fermenting in stainless for a long time and not looking at the beer until it's either going into keg, or coming out of a faucet/tap.

IMO, very little good can be gained (if any) by having clear fermenters, or looking in ones that are not. With clear fermenters, you need to keep them in a dark room to prevent UV/light from skunking them (reaction of the hops).
 
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johnt_mn

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You can also learn to not give any F's about looking at the beer as it's fermenting. I did that early on. Been fermenting in stainless for a long time and not looking at the beer until it's either going into keg, or coming out of a faucet/tap.

IMO, very little good can be gained (if any) by having clear fermenters, or looking in ones that are not. With clear fermenters, you need to keep them in a dark room to prevent UV/light from skunking them (reaction of the hops).
To each his own. It sounds like you're quite a serious brewer making many many beers. I'll probably never make more than a couple per year and enjoy seeing visible signs of the process, and my fermenter is in the basement so no UV issues. Cheers.
 

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Yeah, I have the Big Mouth Bubblers and love them. Also ferment in a basement. Like to see through them to see the fermentation start, like to see the krausen, like to watch it fall, like to see it get clear and that's how I know it's time to keg it. And I can see the yeast sediment and stop just a moment before it's about to get into the line leading to the keg. I wouldn't trade it.
 

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I'll probably never make more than a couple per year and enjoy seeing visible signs of the process, and my fermenter is in the basement so no UV issues.
UV wavelengths are not the only ones that can skunk beer. If using a transparent fermenter, I recommend keeping it covered with an inverted black trash bag. You can poke a hole in the bottom (top after inverting) to accomodate the airlock/blowoff/bladder/whatever.
 

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To each his own. It sounds like you're quite a serious brewer making many many beers. I'll probably never make more than a couple per year and enjoy seeing visible signs of the process, and my fermenter is in the basement so no UV issues. Cheers.
This is where the Tilt hydrometer is useful. A bit expensive and I’ve had issues getting mine calibrated but its really nice to be able to pull up your hydrometer on your phone and monitor fermentation activity without opening your fermenter and risking contamination.
 
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