Secondary Lager Fermentation Slow?
Secondary Lager Fermentation Slow?
In the past, I only ever did top fermenting styles. I had to depressurise my bottles sometimes even more than once (using swing top bottles, luckily, this is not too awful). Now I made a Vienna Lager and even though I can‘t even really cold crash the bottles (I have them sit outside at maybe 10°C instead due to a lack in fridge space), my secondary fermentation is way slower than I’m used to. Is that to be expected?
With ales, I opened the bottles the day after starting secondary, and it sometimes was a deafening bang already. Now, I waited maybe even two days and haven‘t got more than a shy little pop.
I used powdered sugar (mixed with sterile water 1:1) to feed the yeast in secondary fermentation because I didn‘t have anything else in the house when I found the time to bottle. Is that maybe an issue?
how much sugar ended up per bottle? my book says 6.5g/l for a light lager during secondary. also what are your temps?
That’s about it, 6 g/l. I ferment in my garage and the highest it went in primary was close to 20 degrees, just before it was done (nice coincidence that it did a diacetyl rest that way). When bottling last Tuesday, it was more like 10, and it’s somewhere in that ballpark since then, warming up slightly the last few days.
You should leave your bottles to condition for two weeks, that loud pop you heard after one day carbing with ale yeast is all the CO2 pressure in the neck of the bottle escaping instead of slowly dissolving back into the beer had you given it time.
Yeah I know. I ever only broke one bottle or so, and rarely - if ever - undercabonated, so I'd say that with ales, I'm pretty OK. :)
Lager styles usually take longer in secondary leave it at least week to pressurize.
Which yeasts did you use?
Classic: W-34/70 lager yeast. I waited quite some time though to assure primary fermentation was really over in order not to burst any bottles. So it's also entirely possible that there is just very little yeast in the individual bottles to get secondary fermentation going.
Can't wait to start kegging...
I brewed in about the same style but mainly with S-185. If you measure gravity during fermentation you can put it in bottles with ~4,5°Bx and skipp adding sugar.
It is enough to pressurize it and fermentation isn't completely stopped (it is just slowing down). After week in 10 - 12°C it should be pressurized.
When I miss this window I add only about 3.5 g of sugar per bottle and 30g per 30l keg.
do you have an update on how secondary is coming along?
I left the bottles alone, zero blasts so far. I already had to try one out of curiosity just recently, and it was mildly carbonated but went stale pretty quickly and had very little head retention. So it seems to me that letting them sit for another week or so is the way to go.