Gerwin yeast

[Scubabrewer]

Hi fellow brewers
After a long career as a home brewer, with plenty of success and my fair share of failures, I have had to endure an event I never thought would happen - a whole batch of flat bottled beer. I remember a few years ago having to wear a welders mask and industrial gloves to open a lively brew that had burst! Sugar plus lots of (gerwin) yeast and 2 weeks in the 17degC incubator but still flat beer! All the numbers were right, 66deg for mash, 80deg for sparge, 90 mins boil, cooled to 24deg with a fully working starter. It fermented at 17 deg in about 2 days, far too quickly I thought and was so lively I lost 250cc through the bottle air lock. Has anyone else had this problem with this yeast? I will not use it again as I have had so many great brews with SO4 I am drinking GW's Jennings Cockerhoop that is better than my (very good) real ale local. Clear as a bell, lovely head, great taste , what can I say? I have a dilemma now. To leave the GW porter and see if it improves or open a few and try to inoculate it with a working starter and some conditioning malt extract. Anyone out there who could help?
Best regards
Scubabrewer

 

[oldbloke]

Which Gervin yeast? They make quite a few.
What was your priming&conditioning regime?

 

[Scubabrewer]

Hi Oldbloke - many thanks for the reply. I used GV12. Racked off from the primary FV into a sealed container then bottled after one week with half a teaspoon of sugar per litre. Left in the incubator at 17deg for two weeks then in the garage (7 deg) for four weeks. Plenty of yeast sediment in the bottom of the bottles but no Fizz. I might try to add a small volume of working starter and some malt extract to a couple of bottles then leave it in the warm for a few weeks.
Cheers
Scubabrewer

 

[oldbloke]

I see it claimed on the web that GV12 is in fact Nottingham.
I think you may be a bit low on the priming sugar, and 17 may be a weeny bit low too - I've been having trouble with primary ferments lately in a room that drops to 16 overnight.

 

[Scubabrewer]

Hi Oldbloke

Sorted then - two bottles at 20degC for 2 weeks and two bottles with yeast/malt inoculation. Wonder if either will work? Interesting to give it a try as the (flat) porter does taste pretty good.
Cheers
Scubabrewer

 

[oldbloke]

Standard crown caps I suppose? My one failed carbonation was using those plastic reseal thingies

 

[Chris_1984]

How many gallons did you brew, what was your OG and how much yeast did you pitch? (sometimes to be extra sure, I use Mr. Malty's Yeast Pitching calculator)

 

[Scubabrewer]

Hi Chris

Length was 23L, OG 1.048 and I used one packet, 11g I guess?

The initial fermentation went off like a rocket even at 17deg and finished in less than 2 days down to 1.012.

Any ideas?

Cheers

Scubabrewer