Fermenting Lager Problem?

[arksnoah21]

G'day all,
I've been fermenting a lager in a primary fermenter for the last 3 weeks and was getting ready to keg it yesterday. However, when i tested it, its reading had dropped from an OG of 1041 down to 1014 (an alc/vol% of around 3.5). The liquid in the hydrometer tube was also really carbonated, with bubbles floating rapidly to the top (I had to wait a little while so i could get an accurate reading through the bubbles). I've been brewing for around 5-6years, quite seriously over the past 2 years though, and this has only happened once before. I know that if i keg it, i'll just be pouring head, and if i bottle it, the damn bottles will near explode.

I have no idea what has happened and can't understand how it can be so carbonated whilst I have an airlock fitted. I'm assuming the beer is still fermenting, and can still see some small bubbles on the surface, though not quite the light film I'm used to seeing. As a result I am happy to leave it for a bit longer and hope its just fermenting really really slowly, but i don't want to do this and wait if the beer has gone sour. It tasted relatively ok, but probably not how i was expecting (it is a new recipe that i haven't tasted before though, extract pale malt with nelson sauvin and cascade hops, and i know the sauvin imparts a certain citrus bitterness). Anyways, as I don't have immediate access to a homebrew shop to give them a sample I was wondering if anybody has had this happen and if they had any words of wisdom? Should I transfer to a secondary fermenter, please help?

Cheers
Sim

 

[Fents]

my understanding is a primary ferment will carbonate wort just a touch. not enough so you can drink it straight away (unless you really want to) but enough that you would see bubbles in a hydro test jar...

really need to know what yeast you used so you can work out the attenuation....1041 - 1014 does seem to be a bit on the high side tho, i'd be leaving it for a few more days.

 

[WitWonder]

What yeast are you using? 1041-1014 is an apparent attenuation of around 65% so how does that compare to your yeast profile?

If you have access to a fermenting fridge (I assume you do as you're fermenting a lager) you could try a diacytel rest at around 18 degrees for three days then see what the attenuation is. Someone with more knowledge of kits might be able to tell you if 65% is as much as you'll see, based on the fermentables you have. As you suggest, you could secondary it for a while instead of the diacetyl rest if you dont have a fermenting fridge.

As for the bubbles I don't believe this has any effect on your final co2 volumes in the bottle.

 

[arksnoah21]

my understanding is a primary ferment will carbonate wort just a touch. not enough so you can drink it straight away (unless you really want to) but enough that you would see bubbles in a hydro test jar...

really need to know what yeast you used so you can work out the attenuation....1041 - 1014 does seem to be a bit on the high side tho, i'd be leaving it for a few more days.

I used the saflager s23 (country brewer brand not fermentis). It was kept under the house at a constant 14/15 degrees. And unfortunately I don't have access to a fermenting fridge.

 

[Bribie G]

That's a good temperature for s-23, I've used it at those temps here in the (short) winter. If you can get it warmer I would agree with witwonder about raising the temp for a few days to finish it off. I've got a lager in the fridge at 15 degrees and that's exactly what I'll be doing to it, then cold crash it down to 2 degreesfor a week before bottling. You don't want to keg too early or you may end up with a diacetyl twang that you don't want in a lager - a few more days at a warmer temp should prevent that.

 

[floppinab]

If you are worried about overcarbing just slow carb your keg and test it every day or so till it hits something your happy with. For bottling just back off your bottle sugar a bit.
Lagers tend to hang on to a bit more CO2 in solution from the primary compared to ales given the lower temps. If you're really worried about it, as others have said bring the temp up for a few days and run it to a secondary, both should bounce a reasonable amount of the CO2 out of solution.