I can't figure this out. A fermentation question

[Sadfield]

I would check the accuracy of your thermometer that you use during mashing. If it's a digital one it could have gone awry and you are now mashing a few degrees higher. Extra dextrines from a higher mash temp added to 9% dextrine(crystal) malts would definitely give yeast a harder time, without affecting your OG.

To check calibration, I fill a pint glass with ice cubes and top up with water for 0c, and pop the lid open on a domestic kettle whilst boiling, this maintains a rolling boil for 100c.

Sent from my E5823 using Tapatalk

 

[Saisonator]

One of the reasons they say don't make a starter with dry yeast is that people pitch it dry into the wort, killing loads, then you just spend time getting it back to where it would be if you rehydrated. So if you're going to make a starter with dry yeast then rehydrate first at 35 to 40c as temperature makes a big difference to viability.

https://bkyeast.wordpress.com/2013/03/13/more-on-yeast-rehydration/

If you need more yeast than you've got then making a starter from dry isn't a bad thing to do.

I am really surprised to read that, especially after following the manufacturers instructions when rehydrating my last packets of yeast.

https://fermentis.com/wp-content/uploads/2018/03/SafLager-W-3470.pdf

 

[treebeard]

I would check the accuracy of your thermometer that you use during mashing. If it's a digital one it could have gone awry and you are now mashing a few degrees higher. Extra dextrines from a higher mash temp added to 9% dextrine(crystal) malts would definitely give yeast a harder time, without affecting your OG.

To check calibration, I fill a pint glass with ice cubes and top up with water for 0c, and pop the lid open on a domestic kettle whilst boiling, this maintains a rolling boil for 100c.

That is possible too, I use two digital ones, I'm off to check.

 

[treebeard]

Well this one just gets weirder. On Saturday as mentioned I pitched another half packet of US 05 and upped the temp to 22°. On Sunday there were some bubbles from the blow-off tube, great I thought, so today it's still bubbling every 3-5 minutes or so. I took another gravity reading today and it has not moved even a point. It's still 1.020! Why the heck is it still bubbling that frequently, Iv'e never experienced such bad behaviour before in a brew, it's very naughty beer indeed.

 

[Sadfield]

The warmer a beer is, the less C02 it will contain. A 2.5 degree C raise in temperature will release roughly 0.1 g/L of Co2. Not sure whether the blow off activity your seeing relates directly to c1.5g of Co2 being lost, though. It's about 0.75L of Co2 at room temperature and atmospheric pressure (so google says).

 

[Drunkula]

I am really surprised to read that, especially after following the manufacturers instructions when rehydrating my last packets of yeast.

I just googled to double check and Palmer and Beersmith say the same. On a BrewStrong podcast Jamil was saying the same thing as somebody said on here, that commercial packs of the same yeasts have rehydration instructions on them, and they think they don't trust the public to not balls it up and end up cooking it. Looking at those graphs with the strain they were using anywhere around 30c looks good enough.

http://howtobrew.com/book/section-1/yeast/preparing-yeast-and-yeast-starters
http://beersmith.com/blog/2018/01/03/the-right-way-to-hydrate-dry-yeast-for-beer-brewing/

With most beers you will get away with dry pitching but if there's a way so easy that could avoid a stuck ferment then I do it.

 

[treebeard]

The bummer is I dry hopped it at 14 days with a sh*t load of hops, it was only after that did I take a gravity reading only to discover it was way off. Oh well I guess I'll leave it until after the bank holiday, if it's still the same I'll get it bottled.

 

[treebeard]

With most beers you will get away with dry pitching but if there's a way so easy that could avoid a stuck ferment then I do it.

I am definitely going to re-hydrate for my next brew. My flask arrived today, just waiting for the stir-plate.

 

[Pavros]

I just have more questions than answers - sorry

Is there any reason you take it off the trub after 6 days rather than leave it for the whole of the fermentation?
If you are going to bottle after 14 days or so, does it make any difference?
Is there any danger that, by removing the trub, you have not left sufficient yeast in suspension to complete the fermentation of a higher gravity beer?

 

[treebeard]

Is there any reason you take it off the trub after 6 days rather than leave it for the whole of the fermentation?
If you are going to bottle after 14 days or so, does it make any difference?
Is there any danger that, by removing the trub, you have not left sufficient yeast in suspension to complete the fermentation of a higher gravity beer?

Hi Pavros trub, as you may already know, is composed of protein, hop grit and other stuff that didn't get left behind in your boiler. So there's really no harm removing it, so I like to get it off the beer, personally I think the beer is cleaner tasting, probably just my imagination!
I always ferment for two weeks, then dry hop for 4-5 days, then I check the gravity over three consecutive days to make sure it's stable before I risk bottling.
I think I under pitched this beer for the high OG, my own stupid fault for not checking the calculator first. In the past I have not had an issue with fermentation completing after dumping trub.

 

[Pavros]

Ah sorry. I probably meant 'is there a danger that you could have removed some yeast with the trub (although it would probably be dead at this point)?'
If it's possible, then this would increase the effect of any potential underpitching.

I understand you saying that you think you get a cleaner tasting beer by removing the trub. I wonder if anyone has done research into this. Even a blind tasting experiment would be interesting.