To rehidrate or not!

[Andyhull]

Hi all,

When i did my last brew (Admirals Reserve) i found that at the end of fermentation there was quite alot of yeast particles floating on the top of the brew where i had sprinkled it on so not sure all the yeast was absorbed/used.

This time with my latest brew i rehydrated it in 300ml of luke warm water 22c before i started the sanitising and brewing of the IPA, what i found was that the brew got going much quicker at around 5 hours with a steady stream of bubbles from the air lock.
After looking in the FV i also found that the foam on the top was very clean too with no particles on the top like the previouse brews so for me from now on i will be rehydrating every time :thumb:

What are your preferences for adding the yeast, do you hydrate or not and which ever you do, do you have a reason why?

Andy

 

[Mark1964]

Can't see what warm water would do. Yeast needs sugar to start working. We always rehydrate dried yeast 1 to get it fermenting and 2 its better to see if It's a duff yeast. I would rather test a yeast in some warm wort rather than throw it in 5 gallons only to find it doesn't work

 

[Muddydisco]

Can't see what warm water would do. Yeast needs sugar to start working.

Using warm water will produce a yeast cream, it won't start converting the sugars to alcohol but it will wake it up ready to go, as soon as it finds sugar.

See the Fermentis instructions

Pitching instructions: Re-hydrate the dry yeast into yeast cream in a stirred vessel prior to pitching. Sprinkle the dry
yeast in 10 times its own weight of sterile water or wort at 27C ± 3C. Once the expected
weight of dry yeast is reconstituted into cream by this method (this takes about 15 to 30
minutes), maintain a gentle stirring for another 30 minutes. Then pitch the resultant cream into
the fermentation vessel.
Alternatively, pitch dry yeast directly in the fermentation vessel providing the temperature of
the wort is above 20C. Progressively sprinkle the dry yeast into the wort ensuring the yeast
covers all the surface of wort available in order to avoid clumps. Leave for 30 minutes and
then mix the wort e.g. using aeration

I rehydrate as I can, sometimes if it's a fresh packet it goes straight in dry, but always stir after it has hydrated to stop it getting missed like you had Andy. If it's older or been in the fridge I will hydrate it using warm water rather than messing around weighing out sugar in milligrams

 

[Andyhull]

I read an article by aleman a while back that stated yeast should be hydrated in water only at first as the protective membrane couldn't control the flow of particles/fluids (etc) in the beginning so was advised to rehydrate in water.
I can see what you mean about it not actually fementing though, suppose i could add a half tsp of sugar to get it going!
I wouldn't have any warm wort until im about ready to pitch!

 

[Aleman]

Rehydrate in water ONLY Times and temperatures vary depending on yeast strain (so check with the manufacturers website first).

 

[alanywiseman.]

I have started rehydrating the yeast as it makes more sense than pitching it dry. However one thing that has always confused me is why is it ok to rehydrate the yeast but not make a starter from a dried yeast?

 

[Andyhull]

I think you can make a starter from dried yeast but it needs to acclimatise to the new wet surroundings so the membrane can control the flow into the yeast particle, then you can add wort (etc) to it to get it going! (I think)

 

[Mark1964]

I've never used water. I've always used wort that has been boiled for the 90 mins. It's then cooled to 20 degrees and the dried yeast pitched.

 

[Andyhull]

I've never used water. I've always used wort that has been boiled for the 90 mins. It's then cooled to 20 degrees and the dried yeast pitched.

I think in alemans thread it says something about mortality rate :lol: of yeast that cant stand the wort/solution so you don't get as good a start as you could from adding just water initially.
Im not sure but also remember somethig about the yeast being able to ferment cleaner/better if this was done!

Maybe aleman could quote his post?

 

[Aleman]

I have started rehydrating the yeast as it makes more sense than pitching it dry. However one thing that has always confused me is why is it ok to rehydrate the yeast but not make a starter from a dried yeast?

Consider that a packet of dried yeast (11 or 12g) contains enough yeast to ferment 25Litres of beer . . . Pitching it into a starter of a pint is not going to cause any yeast growth (The purpose of a 'starter'), and has a significant detriment to the health of the yeast (Up to 50% reduction in viability) . . plus dried yeast are 'encouraged' to produce energy reserves (trehalose amid others) during the final phase of production before being dried. . . .When you add the yeast to water they rehydrate properly (the yeast cells absorb only water, then become selectively permeable) and the Trehalose reserves see them through this difficult phase, when they are subsequently pitched into wort they get to work straight away. . . . In a small starter they eat up all the trehalose, plus any sugars in the starter, and then go dormant . . . until pitched into the main batch . . . wasting all the effort the supplier has put into providing a yeast that is fit for purpose..

I actually do make a starter with dried yeast . . . but it is generally around the 20-25L size :whistle: :whistle:

Never, ever, ever use sugar in a beer yeast starter, as it causes the yeast to switch a few genes on that favour the consumption of simple sugars in favour of maltose . . . also resulting in a delay when pitched into a maltose rich wort . . . the other genes require turning on to produce the maltase enzymes..

 

[Aleman]

Maybe aleman could quote his post?

Not blooming likey!! it's actually a 2 page thread

How to . . . Rehydrate Yeast

 

[Andyhull]

Not blooming likey!! it's actually a 2 page thread

Never, ever, ever use sugar in a beer yeast starter, as it causes the yeast to switch a few genes on that favour the consumption of simple sugars in favour of maltose . . . also resulting in a delay when pitched into a maltose rich wort . . . the other genes require turning on to produce the maltase enzymes..

The link is just as good and i accept my telling off :lol:

Thank you :thumb:

 

[jonewer]

I cant imagine why anyone would want to rehydrate dried yeast. Other than masochism.

I've never rehydrated and never had a brew that didnt start gurgling within a couple of hours of pitching.

 

[shearclass]

I cant imagine why anyone would want to rehydrate dried yeast. Other than masochism.

Jesus! Is this a serious comment!? Have you read any of the information provided by Aleman? One of the few people who actually knows what he is talking about on here?

 

[dennisdk2000]

I cant imagine why anyone would want to rehydrate dried yeast. Other than masochism.

If adding a bit of dried yeast to a bit of water of a certain temperature, leaving for a bit and then stirring a bit is masochism then I think I've rather misunderstood what 'masochism' means... and it sounds a lot duller than I expected after reading the reviews of Fifty Shade of Grey...

Dennis

 

[alanywiseman.]

I have started rehydrating the yeast as it makes more sense than pitching it dry. However one thing that has always confused me is why is it ok to rehydrate the yeast but not make a starter from a dried yeast?

Consider that a packet of dried yeast (11 or 12g) contains enough yeast to ferment 25Litres of beer . . . Pitching it into a starter of a pint is not going to cause any yeast growth (The purpose of a 'starter'), and has a significant detriment to the health of the yeast (Up to 50% reduction in viability) . . plus dried yeast are 'encouraged' to produce energy reserves (trehalose amid others) during the final phase of production before being dried. . . .When you add the yeast to water they rehydrate properly (the yeast cells absorb only water, then become selectively permeable) and the Trehalose reserves see them through this difficult phase, when they are subsequently pitched into wort they get to work straight away. . . . In a small starter they eat up all the trehalose, plus any sugars in the starter, and then go dormant . . . until pitched into the main batch . . . wasting all the effort the supplier has put into providing a yeast that is fit for purpose..

I actually do make a starter with dried yeast . . . but it is generally around the 20-25L size :whistle: :whistle:

Never, ever, ever use sugar in a beer yeast starter, as it causes the yeast to switch a few genes on that favour the consumption of simple sugars in favour of maltose . . . also resulting in a delay when pitched into a maltose rich wort . . . the other genes require turning on to produce the maltase enzymes..

Thanks for that Aleman. I had always read never to make a starter with dried yeast but it now makes sense to me.

I dread to think what size your fermenter is if you are making 20-25L starters :shock: