Lager Fermentation Question

Hi,

I brewed a lager beer last weekend, (OG1.045) and I used a pack of the Wyeast Czech Pilsner yeast (liquid activator - direct pitch). The smack pack had worked fine (swollen up nicely) at around 16-17 degrees C and I pitched it into the wort at around 15 deg C. The wort was very well aerated when I pitched.

My fermenter was in a fermentation chamber set to 6.5deg C (the recommended range for this yeast is 5-8, so bang in the middle). It probably took around a day to get down from 15 to 6.5.

I have not noticed too much bubbling from my airlock, and I did a gravity test and see the gravity is moving downwards (dropped to 1.040 after 6 days) but the fermentation is not nearly as strong as I would have thought. Also, I got a significant cold break, which has now all settled at the bottom of my fermenter, and so when I did my sample for my gravity reading, I got beer without the cold break stuff in it. (The cold break was obvioulsy all mixed in when I did my OG reading before fermentation)

Do you think my fermentation is "real" (ie the drop on gravity comes from fermentation) or from the fact my latest sample had no cold break material in it?

Does cold break material in suspension affect the gravity reading anyway? (Someone told me anything in solution affects readings, but things in suspension do not?)

Is this too slow for a lager fermentation? (I usually brew ales so have nto experienced this before)?

What should I do, if anything, to salvage this and get it going?

The beer is quite clear, the taste is very sweet obviously but has awesome malt flavours evident, and I really want to make this batch a winner.

What do you think?

At that temperature fermentation is supposed to be slow, especially with the rather low pitching rates that we home brewers use as compared to commercial breweries. I personally ferment my lagers at around 10 °C and it takes me about 8 days to fully ferment an OG 1050 beer.

If anything, you might try pitching colder next time, as such a large temperature drop might shock the yeast and slow fermentation down, possibly even stop it altogether. Commercial lager breweries pitch at fermentation temperature and if anything let the temperature increase a little as fermentation starts. Maybe next time try cooling both the wort and the yeast down to 10°C before pitching, and then try to lower the temperature in the course of two to three days. Aerating only after the wort has reached 10°C is also a good idea, as you will get a higher concentration of oxygen.

What you have been told regarding solution vs suspension and specific gravity is correct.

Cheers,

Vale

ok, then I think fermentation is happening, because I am seeing a drop (albeit a slow one) in gravity. I will give it another 5 or 6 days and see if it is still dropping, or has stopped.

If it were to have stopped, do you have a suggestion as to what I might do? Heat it up a bit, aerate/shake it about/pitch some more yeast?

Any help greatly appreciated

Pitch more yeast. You really underpitched, IMO. People suggest two vials for a lager, and you are really on the lower end of lager yeast fermentation temperature so definitely more than a single vial. Throw another one on the fire ASAP.

and I think vale's suggestion of 10C is spot on for a lager.

Murray said:

ok, then I think fermentation is happening, because I am seeing a drop (albeit a slow one) in gravity. I will give it another 5 or 6 days and see if it is still dropping, or has stopped.

If it were to have stopped, do you have a suggestion as to what I might do? Heat it up a bit, aerate/shake it about/pitch some more yeast?

Any help greatly appreciated

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Definitely do not aerate or you'll get all sorts of off-flavors through oxidation. Gently stirring the yeast cake up can help, but raising the temperature is definitely your best line of defense. I'd raise to 10°C right away and then if necessary go all the way to the highest allowable temp for this type of yeast, as recommended by the manufacturer.

Besides higher temps, I found yeast nutrients a must for fermenting lagers. My personal preference goes to Servomyces, though a bit pricey they really speed fermentation up.

Cheers,

Vale

Thanks Guys. I will raise temperature to 10C straight away, and will gently agitate the yeast cake to get things moving. I willl see if that works before pitching more yeast. The Wyeast activator packs are 100bn yeast cells and are pretty decent sized packs. If I don't get anything in a few days I will get another pack of yeast in there.

Murray said:

Hi,

The beer is quite clear, the taste is very sweet obviously but has awesome malt flavours evident, and I really want to make this batch a winner.

What do you think?

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This is definitely not a good sign, you want the beer to turn all cloudy during primary, which is a sure sign that the critters are really busy chewing on those sugars. It'll clear up nicely once they're done and you've cooled down to lagering temps. Crank that thermostat up pronto!

Cheers,

Vale

Murray said:

Thanks Guys. I will raise temperature to 10C straight away, and will gently agitate the yeast cake to get things moving. I willl see if that works before pitching more yeast. The Wyeast activator packs are 100bn yeast cells and are pretty decent sized packs. If I don't get anything in a few days I will get another pack of yeast in there.

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Incidentally, what size batch are you brewing?

Vale

The batch is a shade under 20 litres, so about 5 gallons in a glass carboy

At this point, there isn't much you can do except wait it out. Keep it at 50 degrees (F), and let it go. You need far more yeast than you pitched, but the yeast reproduce and then get to work. For your next lager, make sure you make a HUGE starter (consult mrmalty.com) and pitch just a shade under fermentation temperature and lit it rise to the desired temperature.

This time, since you are having some activity (SG falling), leave it alone! Don't swirl, raise the temperature, or otherwise mess with it. You'll have some off-flavors from the long lag time and pitching at a warm temperature, but that should fade with lagering.

Lagers are a bit more trouble- they need far more yeast than a single "smack pack", and they need strict temperature control. But they can be worth it!

Thanks Guys. This is my first lager, so I am kind've OK with a failed batch. A very clear message through this is that I need to use more yeast going forward, so that I will definitely do for my next batch. I will also pitch into wort at fermentation temperature. A question on that though? With my immersion cooler, I can get from boiling to around room temperature really quickly (under 10 minutes), but then to get to the lager fermentation temperature of around 8C, I need it in the fermentation chamber overnight at least. Can you leave the wort like that then pitch your yeast the next morning, to pitch at fermentation temperature?

Murray said:

Thanks Guys. This is my first lager, so I am kind've OK with a failed batch. A very clear message through this is that I need to use more yeast going forward, so that I will definitely do for my next batch. I will also pitch into wort at fermentation temperature. A question on that though? With my immersion cooler, I can get from boiling to around room temperature really quickly (under 10 minutes), but then to get to the lager fermentation temperature of around 8C, I need it in the fermentation chamber overnight at least. Can you leave the wort like that then pitch your yeast the next morning, to pitch at fermentation temperature?

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Probably. But it does make me uncomfortable to not pitch right away. Can you submerge your pot in ice water, along with the wort chiller? Or pump ice water through the chiller?

Murray said:

The batch is a shade under 20 litres, so about 5 gallons in a glass carboy

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I regularly pitch up to 28 liters with a single Wyeast Activator smack-pack and never had any problems with fermentation getting stuck or lasting too long, but fermenting colder than 9-10°C is probably asking a bit too much. For that you will definitely need much higher pitching rates and very high oxygenation rates to start it off too. A starter is probably the best option in that case.

If your tap water is cold enough you might think about switching to a plate chiller instead of an immersion one. If properly sized it will allow to cool your wort off to near pitching temperature without taking too long. A counter-flow plate chiller is much more efficient than a simple immersion one.

Cheers,

Vale

For fun, check out the ideal pitching rate on mrmalty.com.

Here's a link: http://www.mrmalty.com/calc/calc.html

Also, he has GREAT information about yeast, yeast health, and why it's important to pitch at the correct rate. If you've been pitching one vial or smack-pack, I think it'd be very surprising.

Thanks Guys. I have raised my temperature to 10c. I figure if I need to go get another smackpack I might as well get 2 and start another batch since I have grain and hops aplenty. I am going to give it a couple days at 10c, and if no luck, will get out the starsan and have another crack from the top. Thanks for your help on this. Lager certainly is a little trickier than ale, but I am going to get it right in the end!

Yooper said:

If you've been pitching one vial or smack-pack, I think it'd be very surprising.

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Life is full of surprises.

Murray, any success so far? Keeping fingers crossed for you.

Vale

Vale said:

Life is full of surprises.

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This sort of thing I simply cannot understand. Do what you like with your own beer, of course. And it may even be true that your beer has no problems when you under pitch.

But suggesting (indirectly) to someone new to lagers or to brewing in general that Chris White (White Labs), Gordon Strong, Jamil Zainashef, the NHC and Ninkasi judges, and other award-winning brewers are somehow mistaken when they tell us the important of proper pitch rates seems disingenuous at best.

Piratwolf said:

This sort of thing I simply cannot understand. Do what you like with your own beer, of course. And it may even be true that your beer has no problems when you under pitch.

But suggesting (indirectly) to someone new to lagers or to brewing in general that Chris White (White Labs), Gordon Strong, Jamil Zainashef, the NHC and Ninkasi judges, and other award-winning brewers are somehow mistaken when they tell us the important of proper pitch rates seems disingenuous at best.

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Never did any such thing. You're just putting words in my mouth. Please stop doing that. Thank you.

Vale said:

Never did any such thing. You're just putting words in my mouth. Please stop doing that. Thank you.

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That's what I got out of your post. Unless you were talking about pitching an ale yeast in which case the comment wasn't of much value to a thread dealing with lager fermentation.

Good info on lager

http://braukaiser.com/wiki/index.php?title=Fermenting_Lagers

Hi Guys

I raised my temperature to 10c as Vale suggested, did not aerate or shake, or pitch more yeast, and after 2 days I got a perfect fermentation started! Bubbling away like mad now at 10c, and though I might get a few off flavours as you guys suggested, I have got a lager brewing now and will hope for the best for a few weeks until I sample a bit before starting to drop into lagering temperatures. Thanks guys, you saved my batch!