1020 final gravity

[Mike1892]

Hi there,

I posted a month or two ago saying that a beer I had made, a coopers IPA with a safale US-05 yeast had stopped fermenting at 1020. I tried stirring it and adding more yeast, but it didn't budge from 1020.

I recently put on another brew, a coopers wheat beer with safale s-04 yeast, and have had the exact same problem again, it is sitting at 1020.

There is no problem with the hydrometer, as I have tested it with two different ones. I was just wondering if anyone can shed any light on this. could it be the yeast I am using, rather than the stuff that comes with the kit?

thanks

 

[Sandimas]

1020 is the famous "stuck brew" point. If you can tell us a bit more about your brewring method we may be able to help e.g. what temperature did you ferment at, what fermentables did you add to the Coopers kits, what volume did you make it up to?

Also, have you had any kits that have gone down lower to the usual 1010 FG?

Personally, I've found the Coopers kits very reliable, even with the standard yeast, and much better than other kits I could name.

 

[Mike1892]

1020 is the famous "stuck brew" point. If you can tell us a bit more about your brewring method we may be able to help e.g. what temperature did you ferment at, what fermentables did you add to the Coopers kits, what volume did you make it up to?

Also, have you had any kits that have gone down lower to the usual 1010 FG?

Personally, I've found the Coopers kits very reliable, even with the standard yeast, and much better than other kits I could name.

ok, with this latest brew I pitched the yeast at 22 degrees, and fermentation has been between 21 and 23. To the coopers wheat kit can I added 1kg wheat spray malt. I also boiled 300g of crushed crystal malt for 40 mins and 100g crushed wheat malt, corriander seeds and orange peel for 10 mins in muslin and poured the liquid into the fv. I made it up to 23 litres.

with my last brew, which also stuck at 1020, I added 1kg of coopers brew enhancer 1 to the coopers IPA kit can. I also added both bittering hops, boiled for an hour and strained water added to fv, and dry hops after approx 5 days in the fv. Temperatures were the same, and also made up the 23 litres.

 

[jonnymorris]

Did you re-hydrate your yeast before pitching? I ask as pitching dry will kill half of it upon contact meaning you'll have significantly under-pitched thereby making a stuck brew more likely.

Bottom line: Re-hydrate dry yeast.

 

[Mike1892]

I didn't rehydrate the yeast, no. But this isn't something I have ever done, and it is only the last two batches this has happened with. I have achieved 1010 with a coopers Australian pale ale in the past using 1kg of light spraymalt and pitching dry.

 

[winelight]

Pitching dry is fine - I always do this - kit instructions say pitch dry, so it follows that they must provide the right quantity of yeast. (At least, that's my theory.) But if you added your own yeast, it probably actually came in a much larger quantity than the size of pack they supply with kits (don't you get 6g with kits, or 11g if you buy a sachet of yeast on its own?).

I've only had one brew "stick" at 1020 and on reflection that's probably due to the somewhat substantial quantity of additional fermentables I added.

None of which really helps the OP - but if adding more yeast and/or stirring things up a bit doesn't change anything, you have to conclude that fermentation has finished, really.

The yeast strain can make a difference too, of course.

 

[jonnymorris]

Pitching dry is fine - I always do this - kit instructions say pitch dry, so it follows that they must provide the right quantity of yeast. (At least, that's my theory.)

Kit instructions are written to make their preparation as simple as possible. Pitching dry will generally work but it far from best practice and will not give you the best results. When pitching dry, 50% will die on first contact with your wort as the yeast cannot distinguish nor therefore regulate what passes through their delicate cell walls. This means you will have under-pitched which Wyeast state can cause;

excess levels of diacetyl,
an increase in higher/fusel alcohol formation,
an increase in ester formation,
an increase in volatile sulphur compounds,
high terminal gravities,
stuck fermentations and
an increased risk of infection.

Do you still maintain that pitching dry is fine?

 

[Mike1892]

Kit instructions are written to make their preparation as simple as possible. Pitching dry will generally work but it far from best practice and will not give you the best results. When pitching dry, 50% will die on first contact with your wort as the yeast cannot distinguish nor therefore regulate what passes through their delicate cell walls. This means you will have under-pitched which Wyeast state can cause;

excess levels of diacetyl,
an increase in higher/fusel alcohol formation,
an increase in ester formation,
an increase in volatile sulphur compounds,
high terminal gravities,
stuck fermentations and
an increased risk of infection.

Do you still maintain that pitching dry is fine?

Thanks for this info, I will rehydrate the yeast in future. It seems odd that two batches in a row have 'stuck' at 1020 when it has worked for me in the past but maybe this explains it. I'll certainly try it next time.

There is no chance that using yeast which didn't come with the kit could be the problem?

Is this a good example of how to rehydrate dry yeast?

[FONT=Verdana, Arial, Helvetica, sans-serif]Preparing Dry Yeast
Dry yeast should be re-hydrated in water before pitching. Often the concentration of sugars in wort is high enough that the yeast can not draw enough water across the cell membranes to restart their metabolism. For best results, re-hydrate 2 packets of dry yeast in warm water (95-105°F) and then proof the yeast by adding some sugar to see if they are still alive after de-hydration and storage.[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif] [/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]If it's not showing signs of life (churning, foaming) after a half hour, your yeast may be too old or dead. Unfortunately, this can be a common problem with dry yeast packets, especially if they are the non-name brand packets taped to the top of malt extract beer kits. Using name brand brewers yeasts like those mentioned previously usually prevents this problem. Have a third packet available as back-up. [/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]


Figure 34 and 35: Dry yeast that has been re-hydrated and the same yeast after proofing. [/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]Re-hydrating Dry Yeast
1. Put 1 cup of warm (95-105F, 35-40C) boiled water into a sanitized jar and stir in the yeast. Cover with Saran Wrap and wait 15 minutes.
2. "Proof" the yeast by adding one teaspoon of extract or sugar that has been boiled in a small amount of water. Allow the sugar solution to cool before adding it to the jar.
[/FONT][FONT=Verdana, Arial, Helvetica, sans-serif]3. Cover and place in a warm area out of direct sunlight.
4. After 30 minutes or so the yeast should be visibly churning and/or foaming, and is ready to pitch.
[/FONT]
[FONT=Verdana,Arial,Helvetica,sans-serif]Note: Lallemand/Danstar does not recommend proofing after rehydration of their yeast because they have optimized their yeast's nutrional reserves for quick starting in the main wort. Proofing expends some of those reserves.[/FONT]

Thanks

 

[serum]

This has happened to me a few times but both times it was with a dark beer kit with extra malt extract added and I also think I was getting dips in the temperature during the night. I've moved my fermenter somewhere that has a more constant temperature and it's working much better now.

 

[jonnymorris]

There is no chance that using yeast which didn't come with the kit could be the problem?

If it was out of date or had been stored incorrectly this wouldn't have helped but the same could probably be said for the kit yeast.

Is this a good example of how to rehydrate dry yeast?

Yes but I have never 'proofed' my rehydrated yeast.

 

[winelight]

Do you still maintain that pitching dry is fine?

Yes thanks - I don't scare easily.

Has anyone done a proper test? That is, either measured any/all of the above scientifically, or better still (because none of the above is relevant unless in the opinion of the drinker it tastes worse) done a taste test (on two identical kits, made identically in every respect other than dry pitching / rehydrating)?

 

[Rivvo]

If 50% of your live yeast cells die when pitching dry you run the risk of under pitching and producing off flavours! esters and possibly even diacetly, for the sake of adding it to 100ml of warm water for 30 minutes is it really worth it?

 

[jonnymorris]

Yes thanks - I don't scare easily.

Wasn't trying to scare you but rather let less experienced brewers on here make their own informed decision about whether to rehydrate or not.

Many homebrewers just sprinkle the dry yeast on top of their wort. Maybe they read it in a book, or their local expert told them rehydration was not necessary. Technically the beer will ferment if you pitch enough non-rehydrated yeast, but you are not giving the yeast the opportunity to make the best beer possible. Besides only having half as much yeast as is needed, the dead cells immediately begin to break down and affect the beer flavour. Why would anyone recommend skipping rehydration?

 

[winelight]

I still wanna see a taste test... I do follow a lot of advice on here and yes the end result is significantly better tasting but haven't seen much scientific evidence for the difference that all these tweaks and improvements make. I'm sure some are more important than others, etc. As Rivvo says, one of the things to take into account is how much effort it is.

 

[Rivvo]

Each to their own, for me it is very little effort to add the yeast to some 30' water for 30 minutes and then pitch, and having once pitched dry and had terrible results (though several other things went wrong with that brew) I wouldn't do it again, certainly the brewferm yeasts and nearly all other independent manafactured yeast instructions I've seen recommend rehydrating, the only yeast packets that I've not seen this on are the kit yeasts. And we all know how good kit instructions are, ie your beer will be ready to drink in 7 days haha

 

[Duxuk]

As we are aware, dry pitching kills more cells than rehydrating. There can not possibly be an advantage to this, so there is no need to test. Under pitching, or killing too many cells, can also allow wild, airbourne yeat, to get a hold on your brew. This is obviously yeast of an unknown nature. Not something you would want.

 

[Mike1892]

Hi there,

Just about to rehydrate the yeast and double checked the instructions above - are you really meant to pitch yeast into water of 35 - 40 degrees c? i thought this would kill the yeast on impact?

Thanks,
Michael.

 

[Duxuk]

35-37C is the best range. This doesn't apply to all yeast but is correct for ale yeasts, in general. It's body temperature for a human. Dogs are slightly hotter, apparently. The yeast seem to like it. Remember to leave the rehyfrated yeast to cool to wort temp. before adding this to the brew to avoid thermal shock.
If you jump into water at less than 13C you are likely to experience shock. You will cramp and may be unable to move or breathe. You can acclimatise your body by repeatedly dunking yourself in cold water. The effect should last for 18 months. Think I'll just have another beer and keep warm meself.:

 

[Mike1892]

Thanks for the reply - I'll bear that in mind for next time. Unfortunately i had to get on with it and pitch dry as i wasnt sure and didnt want to kill the yeast off. Hopefully i wont end up with a 3rd stuck fermentation in a row!

 

[Mike1892]

Bloody confused. I made a coopers recipe called ol' brown dog, using rehydrated yeast, and again it has stuck at 1020. Is anyone aware of anything else i could be doing differently to avoid this?