Lager Fermentation Stalled At 1.015ish... What To Do?

[batemanbrewer]

I'm fairly confident my OG reading was accurate because the temp was somewhere above 20 deg and below 25 deg (can't quite remember exactly), but the reading I took the other day I'm not entirely positive... I took the sample and left it for a few minutes, probably no more than ten minutes, so it may have been too cool. I'll do another reading later in the week and make sure to leave it for ten mins at least, and see if it has changed.

Might be telling you something you already know but there are calculators all over the net to compensate for the temperature you take your SG at. If your hydrometer is rated at 20C that doesn't mean you have to take the reading at 20C, just record the SG and the temp you took it at and plug it into any one of said calculators.

http://dd26943.com/davesdreaded/tools/convert.htm <-- is one I use but it's in farenheit, there are plenty of others around.

 

[andytork]

if it's a lager, it's traditional to raise it to ale temps for a few days to allow any diacetyl to be cleaned up (yeast by-product that tastes/feels like butter/butterscotch/slick) then drop temp again to lagering temps ((not lager fermentation but below 4 degrees: closer to 0-1 is better). This cleans the brew right up and allows it to slowly mature, dropping yeast and other matter out of suspension. Essentially what lager means is to store cold so it's a major part of the process of making one. Some people bottle, allow to carbonate and then cold store. My impression/understanding is that larger volumes mature better than smaller and I prefer to do most of my maturation as a whole mass before priming and bottling. I'm a stickler for old traditions when I know they work and have a point (but only for how I approach things - your beer, your choice).

+1 for that, raise to 18 degrees for a couple of days, then drop to 2-4 degrees for as long as you like (4+ weeks works well). This should get your gravity down and also do the diacetyl rest. I do my lagering in the fermenter before filtering and kegging / bottling. Althouh due to the schedule of lagers I have planned now, I may be lagering in kegs as I only have one lagering / fermting frige currently

I do quite a lot of lagers now and this works really well (mashing a pilsner in the style of an urquell as we speak)

 

[davo4772]

Hello All,

What is an appropriate vessel to lager in? I have a spare 30L fermenter but if I lager a 20L brew then there is a heap of airspace left in the vessel.

Will this affect the brew if lagered for a long period?

Ideally a 20L container would be the go but not keen to spend the money on a carboy/betta bottle.
I notice Bunnings have 20L plastic water containers, I would guess they would be food grade plastic.

Cheers.

 

[manticle]

Nothing re AA% on the Fermentis site, only this:

So he has made a beer using "Body Enhanser" and pitched half the required amount of a yeast with Medium attenuation qualities which has ceased fermentation at 1.015.

1.045 - 1.015 / 1.045 = 66% Apparent Attenuation

Am I the only one who is not surprised ????

Screwy

Good point. While the recipe/instructions suggest it should get lower we all know how inadequate such instructions can be.

The best way to find out is probably the old 'fast ferment a sample' trick - take a sample, shake it up and let it ferment warm until it stops. That should be your final expected gravity.

As for finings - I'm a fan particularly in conjunction with Cold condition/lagering. Cold conditioning on its own and even just time will have a similar effect so it's up to your schedule to some extent.

 

[lukemarsh]

I've been having troubles thinking of a way to heat up the brew, because I've got a pretty good feeling my heat pad wont sit very well in the fridge! There isn't much of a flat or stable surface (the fermenter is sitting on about 3 wire shelves on top of a plastic, feeble looking surface!).... I'm trying to heat up the fridge by using bottles of hot water, but doesn't appear to be doing much good. I think I'll need to get some kind of stable shelf insert (maybe make one out of wood?) for when I bottle and also so I can use the heat pad

... or somehow stick the heat pad to the wall of the fridge!

 

[Nashmandu]

I made a Heineken style lager on the 10th of May and had it fermenting in my brew fridge at around 14 deg using frozen water bottles and a wet towel inside the turned off fridge. The OG was 1.045 and the airlock had been bubbling constantly for the past 10 or so days.

I did a hydrometer reading a few days ago and it was at about 1.020... I did another just now and it is at around 1.015 and the beer hasn't cleared up yet.
The airlock has completely stopped bubbling so I'm guessing it's stopped fermenting. I know you can't just go by the airlock, but it's gone from nonstop bubbling to dead silence with the water at the same level either side of the airlock (it's an S type airlock).

In the Brewing Crafts book (by Mike Rodgers-Wilson) it has the Heineken style lager recipe that I used (uses Brewcraft Dutch Lager kit + Brewcraft #60 German Lager kit converter + Saflager yeast and 22L final volume). In this recipe it says OG should be around 1.041 and the FG around 1.009.

Do I need to do anything to bring my FG down further? I'm just worried that I've gotten my OG reading wrong and therefore it still has more fermentation to go but has stalled (this tends to happen to my beers alot, they all stall at around 1.020 for some reason)...


Another thing is, I have 2 fermenters (one has a cider in it at the moment though)... should I consider secondary fermentation with this beer to make it clearer? I've never looked much into it so my knowledge of it is that basically you just drain the beer into another clean fermenter to get it off the yeast sediment at the bottom and allow the beer to clear... If I'm meant to do this, when is the best time? And what's the best way to do it?

Cheers!

Dude 1.041 to 1.009.......and yours.......1.045 to 1.015.....so its finished .06 higher than expected, but you started .04 higher than you were meant to. It sounds completely normal. Do a couple more hydro tests. If it stays the same of 24hours or so then its all over. pop it in a proper fridge if poss to clear it up abit more.
Im writing in code because im drinking a coffee with the other hand, apologies.

 

[lukemarsh]

Sorry everyone, I've managed to screw up somewhere along the line and got my cider OG mixed up with my lager OG!! The OG for this beer was actually 1.040 not 1.045! So it's still got a bit to go... and is almost exact to the recipe predicted OG.

I've had a think and a play at getting the fermenter higher in the fridge and after about an hour of cursing and frustration I've come to a conclusion. The fermenter will NEVER be high enough in the fridge to be able to bottle straight from the fridge, I'll need to move it to a table or something. For now, I'm doing the diacetyl rest by putting the heater pad underneath the fermenter in the fridge (after all my frustration I found the heat pad actually fit in snugly and stable in the fridge!) which I'll do for the next couple of days, keeping it at around 22 - 25 deg if I can, then I will remove the heat pad and turn on the fridge almost full-bore to keep the beer at as close to 4 deg as possible for a couple of weeks, then I will carefully remove the fermenter from the fridge and place on a table next to the fridge for bottling.

When I pick up the fermenter to take it out of the fridge and put it on the table, will this be too much movement for the sediment and end up just ruining all my efforts in clearing the beer?

 

[technobabble66]

Gettin' a little necro with this thread:

I've got my first attempt at a lager that's stopped a bit high:
The estimated FG should be 1.008.
It's been sitting at 1.011 for 5 days now, at 18°C.

It had a Mash Schedule of 55/63/72/78 for 5/65/25/2 (thermometer seems to be reasonably accurate, but hasn't been checked for a while).
The yeast is S189. 2 packs rehydrated into OG = 1.050, 24.5L, at 13°C.
Held at 13-14°C for a 4 days, then 15°C for 1 day, 16°C for 4 days, 17C for 2 days, then 18°C for the last 5 days.

I'm keen to rack this to a 2nd FV so i can throw another cube of wort onto this yeast cake. I'll probably follow a similar fermenting temp schedule.

So basically, i need to know if a should leave it as is for another few days, or do that but crank it to 20°C, or just rack it to the 2nd FV and get it ready to lager (& get the next batch onto the yeast cake).

Also, minor technicality: i only have 1 fridge. So the fridge will have the 2nd batch of wort/beer in the top, and the temp of the fridge will be set to what that needs. The racked beer in the 2nd FV will sit in the bottom, awaiting the 2nd batch to be ready to lager the 2 of them at 2-4°C.

PS: tasting pretty good for a first attempt!

 

[technobabble66]

Quick bump for the morning crowd.
For the record, if i don't get a response i'll probably just take a punt and rack it to the secondary tonight. See how that goes.

 

[Coodgee]

If it's been sitting at 18 degrees for 5 days it's not going to go any further. I'd say 1.011 is fine.

Maybe ferment your next batch at the bottom of the temp range of your yeast. Not really lagering but it will still be conditioning. Then lager both at the correct temp.

 

[Black n Tan]

From 1.050 down to 1.011 is about 78% apparent attenuation so i think it is likely done (although I have no experience with that yeast).

 

[Coodgee]

1.008 is only an estimate.

 

[technobabble66]

Cheers guys!
Yep, I was erring towards assuming it's at FG and 1.008 was not to be taken too seriously.

@BnT - you sure that's calculated right? I didn't think 100% was actually seen as down to 1.000, as the realistic 100% attenuation still leaves a certain amount of unfermentables. Not correct?
I'm asking partly as the 1.008 is taken from the call on ianh's spreadsheet, which was set at 75% attenuation.

 

[TheWiggman]

Apparent attenuation - percentage of gravity converted where 100% = 1.000. Homebrewtalk's first result on your favourite search engine is an excellent read.

%AA = (OG - FG) / (OG - 1) = (1.050 - 1.011) / (1.050 - 1)

I prefer to think of it as:
%AA = 1 - (FG - 1 / OG - 1) = 1 - (11/50)

Same result, but makes more logical sense to me.

75% AA with an FG of 1.008 yields an OG of 1.032.

 

[Black n Tan]

@BnT - you sure that's calculated right? I didn't think 100% was actually seen as down to 1.000, as the realistic 100% attenuation still leaves a certain amount of unfermentables. Not correct?
I'm asking partly as the 1.008 is taken from the call on ianh's spreadsheet, which was set at 75% attenuation.

I think it is right as wiggman has demonstrated above. It is 'apparent attenuation' because it is based on the ratio of OG and FG, and is not corrected for the density of ethanol. You can get an AA above 100% because ethanol is less dense than water and as such you can get an FG below 1.000. You can convert AA to real attenuation but i think that is largely academic because most yeast manufacturers and brewing software just presents AA. For me I typically get 78-80% AA when I use a long 63C mash and Wyeast 2124, say for a german pilsner.

 

[technobabble66]

Alrighty - thanks BnT & Wiggman

Those calc's for %-age attenuation use real, recorded values.
I think the problem i'm having is with the calc's used to determine an Estimated FG, as the issue seems to be that the attenuation is already being assumed to be ~75% (re: yeast specifications) and that the spreadsheet is coming up with an FG that doesn't fit the actual recorded FG.
I've checked on a few of my other batches's spreadsheets (where estimated & recorded figures generally matched up well) and got the same type of results: an OG=1.050 with an attenuation of 75% is calculated to produce an estimated FG=1.008-9.

So maybe my question should be: How is FG calculated on ianh's spreadsheet?

And how on earth does an assumed attenuation of 75% produce an estimated FG=1.008-9 from OG=1.050 on the spreadsheet, and then the apparent attenuation from those same (later) recorded figures supposedly calculate to be an attenuation of ~83%??

I'm sure there's a good reason, but i can't quite initially see how there can be that inconsistency.

EDIT: At least my main concern is solved - it should be done and i'll rack it into the 2nd FV. Thanks again, guys!!

 

[Black n Tan]

I am not familiar with ianh's spreadsheet, but could the expected FG be based on the target OG rather than the actual recorded OG? Did you hit your target OG for this batch? if not what was your target?

 

[technobabble66]

Target was essentially OG=1.050, and the resulting FG=1.008.
The initial OG was higher (extra boil-off) but was then diluted down to OG=1.050, so that shouldn't be an issue.

No stress - i'll just have to do more reading and work out why i'm seeing an incongruency between the estimated FG and then the AA calculated from results.

 

[technobabble66]

Just out of interest, once I've racked the first batch, when I pour the 2nd batch onto the yeast cake do I need to aerate it?
The 2 batches are a similar OG & vol.
My understanding is the aeration is to facilitate the reproduction of the yeasties. If I've got a "full/complete" population/quantity of yeasties from the first batch, then there shouldn't be much reproduction required. (There'll probably be some splashing as the cube is drained into the FV anyway). Correct?