Off flavours with certain yeast...?

[TheRtHonorable]

Hey guys,

Sorry for the long post, but I've got a problem with off flavours in my beer and thought I'd ask if others have had the same.

I made the switch from kits to BIAB all grain brewing this year, and I've now done five AG brews.

The first one was my 50l boiler on the gas hob, and I had no filter attached to the tap. As a result I had a terrible boil, and all of the break material went into the fermenter. After 14 days or so fermenting, the beer tasted odd. I tried to drink it but gave up once AG#2 was ready. When I finally chucked it out, it was dreadful, and insanely over-carbonated.

For AG#2, I added two 2.75kw elements, and a hop strainer. The hot break was great, and the strainer reduced the amount of **** getting into the FV. Again though, there was some of the strange flavour from AG#1, but I managed to drink it all.

For AG#3, I added an extra step, and poured the chilled wort into a bucket, let it settle for a couple of hours, and then siphoned it into the FV. This left loads of break material behind. I then fermented for 4 or 5 days, at which point the off flavour started to appear, and I siphoned the beer off the yeast cake and into a secondary. The yeast smelled awful. This beer turned out well, but was a bit weak as I added too much water!

AG#4 was the same process as AG#3, but a different recipe and the FVs were kept in my garage at a lower temperature (around 18C). This one turned out nicely, again the yeast cake smelled pretty bad but I took the beer out of the FV after 4 days and later dry hopped it, and the beer was good.

AG#5 is currently underway; today I moved it into the secondary and dry hopped it. It tastes really good, no off flavour at all, yeast cake smells fine, like when I was doing kit brews.

Brews 1-3 were the same recipe (a Bathams clone), 1 was with Gervin G12 (I think..), and 2 and 3 were with S04 yeast. Brew 4 was my own recipe, again with S04. Brew 5 is a different recipe of my own, an Amarillo / MO SMaSH, but with S05 yeast.

So, while I seem to have overcome my off flavour problem, has anyone else had trouble with S04? The major difference between brews 3 and 5 would seem to be the yeast choice. I'd just really like to know people's opinions because when brews 2 and 3 turned out pretty badly I was considering selling up my kit and sticking to buying bottled beer!

Cheers,

Chris

 

[Pakman]

Chris
Are you fermenting the brews at too high a temerature? My first AGs were BIAB and had an unusual taste but as I've completed more brews I finally got rid of it . . . . . until the last two. The ambient temperature has been a lot warmer and the ferment was performed at over 20C and the same taste has started to appear again. I then remebered that I used to use a heater belt around my FV controlled by the STC1000 but the off tastes stopped when I stopped using that. Mine was definitely down to too high fermentation temperature so I've now got a fridge to convert to keep them at 18 or 19C
Graham

 

[TheRtHonorable]

Yeah I had thought it might be temperature.. I was fermenting indoors, and initially I mistakenly thought my beer needed to sit at about 24-26c. This didn't seem to affect my kit brews though.

AG1 was probably a bit too warm, but the more recent ones have been out in the garage where it's cooler. The only method I have to measure temp in the FV is a stick on thermometer strip on the outside, but that's shown 18-20c for the last couple of brews.

The main reason I asked was that I have read about off flavours using S04... Maybe it's more susceptible to problems at higher temps?

 

[Dads_Ale]

I have fermented my last 3 AG brews using S04 at 25c -26c and had no problems although I did bottle it after only 4-7 days in the primary FV. At this temp it only took a couple of day to fully ferment.