I’ve got a lager in the fermentation chamber that will just not take off and start fermenting. I’m not a rookie brewer. I have lots of brews under my belt and have never had a failure until now and I don’t know what’s going on.
The beer is a 5 gallon schwarzbier with an OG of 1.058 that was brewed last Sunday. I made a 5 liter starter of Wyeast 2206. The starter was overbuilt to allow me to harvest ~200 billion cells for future use. I cold crashed the starter upon completion and pulled it out of the refrigerator 30 minutes prior to pitching and decanted the beer. The yeast was then pitched into 50° wort and it’s been sitting there for a week with no activity.
I think about Thursday I checked on it, and nothing was going on, so I took a gravity reading and it hasn’t changed. At that point, I shook the fermentor to re aerate the wort and pitched the additional yeast I saved from the starter. This morning, still no activity. Currently, I’m letting the fermentor warm to 55° to see if that will kick off fermentation. Additionally, I checked the pH of the wort and it’s perfect, at 5.2. I just don’t know what could have gone wrong. I know there’s no infection, or bacteria, or wild yeast, because absolutely nothing is happening in the wort. I’m all out of ideas, anyone else have any?
I haven't used that particular lager yeast but 50F is usually the lowest temp in the White Labs lagers that I used. I would recommend warming it as you say and then waiting a day to see what happens. Some yeast nutrient wouldn't hurt right now if you have some.
If you describe how you made your starter in a little more detail, maybe something was off. Did you use a new starter pack and did you check the date? How long did you let it sit before cold crashing? What kind of activity did you have during the process? Any sort of aeration of the starter?
What kind of fermenter, can you see inside it? Did you check the gravity at the end of the week?
Starter was made with three month old yeast. It spent 48 hours on a stir plate and showed normal activity that I’ve seen on all my other starters. After 48 hours, it was cold crashed. It’s a bucket fermentor and I did recheck gravity today with no change.
I have an ink bird controller taped to the side of the fermentation bucket under insulation. I double checked it with a known calibrated thermometer and it was spot on.
I guess it's most logical to assume the viability on the 3 month old pack was a lot lower than predicted/expected. It could have gotten warm at some point.
I brewed a schwarzbier in April with WLP820 and set to 51F to start and had activity the next morning. (I realize your yeast was different.) I oxygenate my wort. My starter was about 1600ml, built on a stir plate. I've only built a 5000ml starter a few times as I broke my bigger flask soon after I got it. I'm wondering if even though you saw activity in the starter, it may have been weak as you are using a 48 hour period then cold crashing. I don't use a set period of time for the starter but I look for a solid looking krausen before I either cold crash or pitch. It's exponential growth so if you cold crash the starter when there's just a little activity going, you might be on the low side for yeast cell count. I've been forcing myself to cold crash my last 4-5 starters but regardless of that, I always have activity the next day in both ales and lagers.
Did you aerate your wort? Maybe with an unknowingly lower number of yeast cells, no aeration, and potentially on the cold side for that yeast, the yeast were unhappy.
Also, sometimes it helps to search the specific yeast and see what others experiences may have been.
I would have assumed the same, however, you've made a starter with a good activity. I've used far older yeasts without a starter in lagers with good, not great, results. They all fermented though.
Brewfather's yeast calculator is suggesting that maybe you made too large of the starter so the inoculation rate was lower than recommended 25-100 M/ml. Even with a 200B overbuild and keeping it to 4.3 liters, it's too low.
5ityqrid3x4.png
Building the same starter with two packs is closer to right:
qomyfhl1a0k.png
Reducing down to an overbuild of 0 cells and upping the starter gravity from 1.036 to 1.040 gets the inoculation rate just in minimum range with just a single pack.
All of this is based on the assumption that the 3 month old viability was following the model of cell loss over time. If some less than ideal handling compromised it, who knows. In this particular case, it would have been better to gain extra yeast via later harvest rather than overbuild.
Not sure. I used brewdads calculator. I’m thinking it’s a combination of weak yeast and not enough time on the stir plate. I have an even older pack of 2206 in the refrigerator. I may try building it up and repitching with it. I just don’t know how long I can let the wort sit without it fermenting and it remain in good shape.
If cowboy over pitched, he would still have activity.
What chemicals do you use? Sanitizers, nutrients, the whole works, if it isn't malt hops and water, include it.
Calcium chloride, epsom salt, gypsum, and phosphoric acid for water chemistry. Whirlfolock and 1/2 tsp white labs yeast nutrient at the end of the boil. Star San sanitizer. Other than that, nothing is added to the brew.
You would have needed a starter of aprox 400B cells, and with the Troester calculations, you would have had close to 500B. Jamil/White calculations would have you at around 230B. Cut the difference and you would still be under pitched. I've done a 1080 beer with a single White labs pack with 30% viability and still had activity, but after a week or so. I might be about as stuck as your ferment.
You said you checked again today. Did you smell fermentation? Sometimes it's just a pain to get going. The yeast might just need to get a round tuit.
I don’t really smell fermentation. Maybe just ever so sightly I can get a faint smell of CO2 in my fermentation chamber. But maybe it’s my imagination. I’ve always used homebrewdads starter calculator, which is based on braukaisers formulas, and have never had issues before this one.
I’ve got another starter going as we speak. I hope the wort holds out long enough to get it done. It’s gonna take at least two, maybe three steps to build up enough yeast as it’s an old, expired pack.
Sadly from my personal experience, I think it is the yeast. I have done all kinds of yeast prep over the years and it never pays to try to limp old yeast along. Especially with a lager. I have settled on freezing yeast and growing up starters and I have to say, this is the best yeast performance I have had in 20 years of homebrewing. Growing from 25ml to 250ml to 2L (two in parallel for a lager) means your cells are super viable and active. Highly recommend it for people who brew a lot of different styles with different yeasts. I made a video about the process which is on my YT channel (signature).
I always step up my starter from a few hundred ml when the original is old or I'm dubious. I then build this over about a week, ie few hundred ml then a litre then cold crash that, and top up to 3 litres. I check the gravity on the pour off to check it has fermented and can normally see the yeast thickness building up for each build. I did then jump to six litres for a recent barley wine.
I'd warm your wort, give it some nutrients and a bit of rousing. No yeast activity either indicates they no like the environment they are in ( too cold ) or they aren't viable.
Assume you saw krausen, bubbles and a colour change to cloudy as you built your starter and had a good thick layer in your vessel prior to decanting.
Post time 2022-9-18 11:46:01
Author
