Pilsner Fermentation (or lack of?)

[blockley]

I brewed a Pilsner two days ago for the first time.

Following a recipe, I pitched Wyeast Pilsen Lager 2007 and started in the fermentator at 10C.
Yesterday morning it was just about bubbling - a small bubble about every 45 seconds or so, by yesterday evening it had stopped and today nothing's happening.

Should I start to panic (something which I'm quite good at!)

Cheers

 

[Rochefort]

If the starter was active (or the smack pack expanded) and the wort was at the correct temperature, don't worry. Everything is slower at 10C!

I usually don't open the fermenter for at least three days, but if you have a plastic FV you can often see a krausen wreath forming after 24 hours by looking through the FV with a torch. Regarding the lack of activity, sometimes you can see bubbles stuck to the side of the fermenter even if there is little activity in the airlock.

If you are seriously worried just open it up and take a gravity reading.

 

[blockley]

If the starter was active (or the smack pack expanded) and the wort was at the correct temperature, don't worry. Everything is slower at 10C!

I usually don't open the fermenter for at least three days, but if you have a plastic FV you can often see a krausen wreath forming after 24 hours by looking through the FV with a torch. Regarding the lack of activity, sometimes you can see bubbles stuck to the side of the fermenter even if there is little activity in the airlock.

If you are seriously worried just open it up and take a gravity reading.

Thanks, that's re-assuring. I'll bide my time.
Any suggestions what i should do if nothing's happened in a few days?

 

[Rochefort]

Take a look as best you can without opening the fermenter using a torch, if you can't see a foam wreath/krausen today then up the temperature to 12 C. It can take 36 hrs for the krausen to form, with a lager fermentation it starts near the sides of the fermenter and forms a halo before creeping over the whole surface. Sometimes the yeast is just a little too cold to get started.

If you have raised the temp to 12 C and don't see any evidence of activity several hours later, open up and check the gravity, contamination is the least of your worries at this point. If it has barely moved (less than 1.002 difference), repitch with fresh yeast.

 

[foxbat]

How big was your batch, what was the OG and what was the best before date on the pack? Liquid yeasts in cold-fermented lagers really need starters to get the initial cell count up.

 

[Leon103]

Don't worry about it. It's a bottom fermenting yeast. You won't get much of a krausen, if any. Plastic fvs are never air tight. At 10c it will take a couple of days to get going.

 

[blockley]

How big was your batch, what was the OG and what was the best before date on the pack? Liquid yeasts in cold-fermented lagers really need starters to get the initial cell count up.

21L. OG was 1.048. Not sure about the best before date but assume was okay as only just bought it.

 

[Galena]

Plastic fvs are never air tight.

I do take your point, but to be the pedant, that is not strictly true.
Speidel plastic FV's are very airtight

 

[foxbat]

21L. OG was 1.048. Not sure about the best before date but assume was okay as only just bought it.

Unfortunately retailers will continue to sell the packs up to and even beyond the best before date. Where did you buy it? The better retailers quote the date on the website so you can see before you buy. Wyeast packs leave the lab with about 100bn live cells that start to die off immediately. Your lager ideally requires a pitch of 375bn cells. If you're lucky you've just got a slow start. If you're unlucky you don't have enough cells to complete the fermentation. It's not an exact science.

 

[Leon103]

I do take your point, but to be the pedant, that is not strictly true.
Speidel plastic FV's are very airtight

View attachment 45549

Unless not threaded correctly, or threads are worn. Air could escape from where the bung enters.

 

[Galena]

Unless not threaded correctly, or threads are worn. Air could escape from where the bung enters.

Now who is being pedantic None of those are plastic specific, the threads are coarse and not going to wear out for many years, if at all, the cap seals on a gasket. All parts can wear out eventually no matter the material. Any bung could potentially leak, not really relevant to a plastic FV

 

[Leon103]

Now who is being pedantic None of those are plastic specific, the threads are coarse and not going to wear out for many years, if at all, the cap seals on a gasket. All parts can wear out eventually no matter the material. Any bung could potentially leak, not really relevant to a plastic FV

OK all plastic apart from Speidel are susceptible to leaks.

The traditional buckets have a large lid that can easily mis-shape which leads to a poor seal.

 

[Rochefort]

Your lager ideally requires a pitch of 375bn cells. If you're lucky you've just got a slow start. If you're unlucky you don't have enough cells to complete the fermentation. It's not an exact science.

I was going to say that the pitching rate was a little on the high side, but I tried out that calculator and using it gives the correct volume of starter culture even though it doesn't display the actual cell count you would get.

The yeast grow to a maximum cell density between 130 and 160 billion cells per litre no matter what the initial pitching rate was, I have counted them enough times to know that this is true. I think the original poster needed 250 billion cells (Pitch Rates | Wyeast Laboratories), so that would require a 1.72 L starter culture. If you put 100 billion cells in and a 1.72 litre starter it calculates (the impossible value) of 340 billion cells but actually would give the correct pitching rate.

Weird!