Lager Fermentation Question - Home Brew Forums

Register Now!
Home Brew Forums > Home Brewing Beer > All Grain & Partial Mash Brewing > Lager Fermentation Question

Reply
 
Thread Tools
Old 02-20-2012, 09:55 AM   #1
Murray
Recipes 
 
Nov 2011
London, UK
Posts: 84


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?

 
Reply With Quote
Old 02-20-2012, 10:17 AM   #2
Vale
Registered User
Recipes 
 
Jan 2012
Posts: 16

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 10C before pitching, and then try to lower the temperature in the course of two to three days. Aerating only after the wort has reached 10C 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

 
Reply With Quote
Old 02-20-2012, 10:29 AM   #3
Murray
Recipes 
 
Nov 2011
London, UK
Posts: 84

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

 
Reply With Quote
Old 02-20-2012, 10:57 AM   #4
tektonjp
Recipes 
 
Nov 2010
ohmihachiman, Japan
Posts: 817
Liked 90 Times on 67 Posts


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.
__________________
"Beer, well respected and rightly consumed, can be a gift of God. It is one of his mysteries, which it was his delight to conceal and the glory of kings to search out."

The Search for God and Guinness by Stephen Mansfield

Reason: addition

 
Reply With Quote
Old 02-20-2012, 11:18 AM   #5
Vale
Registered User
Recipes 
 
Jan 2012
Posts: 16

Quote:
Originally Posted by Murray View Post
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
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 10C 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


 
Reply With Quote
Old 02-20-2012, 11:28 AM   #6
Murray
Recipes 
 
Nov 2011
London, UK
Posts: 84

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.

 
Reply With Quote
Old 02-20-2012, 11:28 AM   #7
Vale
Registered User
Recipes 
 
Jan 2012
Posts: 16

Quote:
Originally Posted by Murray View Post
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?
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

 
Reply With Quote
Old 02-20-2012, 11:29 AM   #8
Vale
Registered User
Recipes 
 
Jan 2012
Posts: 16

Quote:
Originally Posted by Murray View Post
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.
Incidentally, what size batch are you brewing?

Vale

 
Reply With Quote
Old 02-20-2012, 01:58 PM   #9
Murray
Recipes 
 
Nov 2011
London, UK
Posts: 84

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

 
Reply With Quote
Old 02-20-2012, 02:03 PM   #10
Yooper
Ale's What Cures You!
HBT_ADMIN.png
 
Yooper's Avatar
Recipes 
 
Jun 2006
UP of Michigan, Winter Texan
Posts: 69,416
Liked 7843 Times on 5496 Posts


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!
__________________
Broken Leg Brewery
Giving beer a leg to stand on since 2006

 
Reply With Quote
Reply
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Lager fermentation lagging enricocoron All Grain & Partial Mash Brewing 26 09-13-2011 06:05 PM
First Lager - Fermentation Temp Question joety All Grain & Partial Mash Brewing 2 12-14-2009 02:54 AM
lager fermentation problem bionicbrew All Grain & Partial Mash Brewing 7 08-25-2009 08:38 PM
Lager fermentation schedule fungusamungas All Grain & Partial Mash Brewing 9 06-21-2007 02:10 AM


Forum Jump