Kolsch using Fermentum Mobile FM42 yeast advice

[timtoos]

Hi all, m after some advice please...

I brewed a Kolsch all grain 6 days ago (6/10/19).

OG was 1.048. It was a really good brew day with all numbers just about bang on (apart from having to fish out a wasp from the boil).

Anyway, I was given Fermentum Mobile FM42 from the MM as part of the Kolsch kit. It came with 2 vials as the yeast count is about 20-30 billion. I made 2L starter using both vials and to be fair it was sluggish but it did come round. Once complete (it did take over 36 hours) it was placed in the fridge and the spent starter carefully removed on brew day.

When it was pitched it started off pretty well. The gravity dropped from 1.048 to 1.025 on the afternoon of 9/10/19. Then it all slowed down. Its still fermenting and has a Krausen on the top of the beer. I have just taken another sample today (12/10/19 @ 17:30) and the gravity is at 1.018. The smell and taste isn't amazing now though. It smells like a bad kit beer and the taste a bit sharp.

I have some dried Kolsch yeast which I could pitch as Im not impressed with this FM42 at all. If its a bad batch then should I waste the yeast? Should it be tasting ok at this stage as up to press it hasn't been bad - obviously on the sweet side. Today the smell and taste are definitely different.

Whats your advice?

[guypettigrew]

What are you expecting your gravity at the end of the primary fermentation to be? 1.018 doesn't sound too far off as you're only 3 days into the ferment.

The taste? There will be loads of yeast in the beer--horrid stuff, not meant to be drunk!

If there's no taste or smell of infection then it's worth giving it a couple more days to see what happens.

Are you able to control the fermentation temperature?

Guy

[timtoos]

Hi Guy,

I was expecting 1.008

I'm controlling the temperature at 16C. It controlling nice and tight.

It's 6 days in now, I brewed last Sunday.

Its not tasting or smelling great that's all. Like I say a bad kit beer

[thehaze]

You should raise the temperature to allow the yeast to finish. After 6 days the yeast will not produce any off-flavours, esters, etc. Slowly raise it 1 degree every day or every 2 days. If nothing chages it, you can try to rous ethe yeast, without introducing too much O2. If again nothing happens, you can pitch another yeast that can take the FG lower. Lastly, are you sure your wort had more fermentable sugar than what was already consumed by the yeast? Was the mash temp. OK?