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General Category => Yeast and Fermentation => Topic started by: imperialstout on January 23, 2013, 02:22:13 PM

Title: Don't make yeast starters from dry yeast? WTF?
Post by: imperialstout on January 23, 2013, 02:22:13 PM
Just read in "Brewing Classic Styles" by Jamil Zainasheff and John J. Palmer page 285, bottom of page, NOT to make a yeast starter from dry yeast. Claim it is much cheaper to buy more yeast and hydrate. Surely not everyone who makes a yeast starter uses White Labs or Wyeast.

As for cost, Wyeast would have cost me $20 from Northern Brewer, $6 for yeast and $14 shipping.

Can anyone think of a reason NOT to make a starter from dry yeast? The goal is to increase cell count. How does liquid yeast work well for starters but it is better just to pitch re-hydrated dry yeast?

Will send the authors an email and see what John Palmer has to say in his book, "How to Brew."
Title: Re: Don't make yeast starters from dry yeast? WTF?
Post by: Hokerer on January 23, 2013, 02:26:50 PM
Just read in "Brewing Classic Styles" by Jamil Zainasheff and John J. Palmer page 285, bottom of page, NOT to make a yeast starter from dry yeast. Claim it is much cheaper to buy more yeast and hydrate. Surely not everyone who makes a yeast starter uses White Labs or Wyeast.

As for cost, Wyeast would have cost me $20 from Northern Brewer, $6 for yeast and $14 shipping.

Can anyone think of a reason NOT to make a starter from dry yeast? The goal is to increase cell count. How does liquid yeast work well for starters but it is better just to pitch re-hydrated dry yeast?

Will send the authors an email and see what John Palmer has to say in his book, "How to Brew."

The reason dry yeast starters are not recommended is that part of the process of creating dry yeast involves maximizing the yeast's internal nutrients and such at the moment before drying.  Making a starter with dry yeast actually uses up those nutrients and such.

That's not the case with wet yeast and, since wet yeast cell counts are about half of dry, starters are pretty much always recommended.
Title: Re: Don't make yeast starters from dry yeast? WTF?
Post by: weithman5 on January 23, 2013, 02:35:14 PM
i have made starters before.  i use only part of the pack and make a starter.  in addition i have used a full pack of yeast and then brewed on top of that cake a few times before getting rid of it.  both work just fine
Title: Re: Don't make yeast starters from dry yeast? WTF?
Post by: dmtaylor on January 23, 2013, 02:57:39 PM
If you have extra wort laying around from a previous batch, then making a starter isn't such a bad thing to do if you really want to.  But if you don't have spare wort, then keep in mind that you are blowing extra money on extract to make the yeast starter.  Dry yeast is all about high quality, less fuss and less money.  If you're going to mess around making a yeast starter, well, you're wasting your time AND money IMHO.
Title: Re: Don't make yeast starters from dry yeast? WTF?
Post by: jjflash on January 23, 2013, 03:33:41 PM
Only time I have found it useful to make a starter with dry yeast is stuck fermentation for a big beer.
Best to pitch really active yeast starter to kick start fermentation again.
Sprinkling dry yeast on stuck fermentation has never worker for me.
Title: Re: Don't make yeast starters from dry yeast? WTF?
Post by: redbeerman on January 23, 2013, 03:54:23 PM
Just read in "Brewing Classic Styles" by Jamil Zainasheff and John J. Palmer page 285, bottom of page, NOT to make a yeast starter from dry yeast. Claim it is much cheaper to buy more yeast and hydrate. Surely not everyone who makes a yeast starter uses White Labs or Wyeast.

As for cost, Wyeast would have cost me $20 from Northern Brewer, $6 for yeast and $14 shipping.

Can anyone think of a reason NOT to make a starter from dry yeast? The goal is to increase cell count. How does liquid yeast work well for starters but it is better just to pitch re-hydrated dry yeast?

Will send the authors an email and see what John Palmer has to say in his book, "How to Brew."

The reason dry yeast starters are not recommended is that part of the process of creating dry yeast involves maximizing the yeast's internal nutrients and such at the moment before drying.  Making a starter with dry yeast actually uses up those nutrients and such.

That's not the case with wet yeast and, since wet yeast cell counts are about half of dry, starters are pretty much always recommended.

Making a starter with dry yeast compromises yeast health and viability as hokerer alludes to.  Repitching slurring from formerly dry yeast or making a starter from that would be proper.
Title: Re: Don't make yeast starters from dry yeast? WTF?
Post by: Kaiser on January 23, 2013, 03:59:01 PM
Sprinkling dry yeast on stuck fermentation has never worker for me.

yeast doesn't do so well when rehydrated with alcohol.

hookerer brought up important points about dry yeast and their internal reserves.

Compared to liquid yeast it is not so mych a matter of cell count but what we generally call "yeast health". For liquid yeast a starter is not only recommended for increasing the cell count but also for replenishing reserves that the yeast was living on while sitting in the fridge. If those reserves are replenished, and not spent again b/c the starter was sitting in the fridge for a week, then the lag phase will be shorter and the yeast will perform better in your beer.

Kai
Title: Don't make yeast starters from dry yeast? WTF?
Post by: majorvices on January 23, 2013, 04:07:58 PM
If you have extra wort laying around from a previous batch, then making a starter isn't such a bad thing to do if you really want to.  But if you don't have spare wort, then keep in mind that you are blowing extra money on extract to make the yeast starter.  Dry yeast is all about high quality, less fuss and less money.  If you're going to mess around making a yeast starter, well, you're wasting your time AND money IMHO.

Theoretically, it is a bad idea since dry yeast already have their glycol reserves stored and in suspension and making a starter could cause them to blow their reserves. The idea of making a starter is to grow up enough cells. With dry yeast you can be fairly certain on the # of viable cells in the packet so a starter is not needed and could be detrimental if the starter is too small.
Title: Re: Don't make yeast starters from dry yeast? WTF?
Post by: imperialstout on January 23, 2013, 07:12:35 PM
Thank you all very much. I use dry yeast as no LHBS carries liquid and it is too expensive to order on-line. Had I not read  "Brewing Classic Styles" and posted the dry yeast question, brew day would have involved destroying dry yeast on an expensive stirrer in an expensive flask.

Maybe the monitors can create a sticky not to make yeast starters from dry yeast.
Title: Re: Don't make yeast starters from dry yeast? WTF?
Post by: Joe Sr. on January 23, 2013, 07:44:41 PM
Thank you all very much. I use dry yeast as no LHBS carries liquid and it is too expensive to order on-line. Had I not read  "Brewing Classic Styles" and posted the dry yeast question, brew day would have involved destroying dry yeast on an expensive stirrer in an expensive flask.

Maybe the monitors can create a sticky not to make yeast starters from dry yeast.

You wouldn't be destroying it, exactly.  You would probably be pitching a sub-optimal starter and going through unnecessary trouble.

On the positive side, you can use that stir plate and flask to make starters from stored slurry after you harvest it from your fermenter.  Or grow up some yeast from a commercial bottle, which can be fun.
Title: Re: Don't make yeast starters from dry yeast? WTF?
Post by: liquidbrewing on January 27, 2013, 04:03:10 AM
If you read the instructions for US-05 it says plain as day, "Sprinkle into wort".  And I swear Nottingham use to say, "Do not aerate".  But it also talks about Lysine so, you know, You didn't say the magic word!
Title: Re: Don't make yeast starters from dry yeast? WTF?
Post by: morticaixavier on January 27, 2013, 05:23:52 AM
If you read the instructions for US-05 it says plain as day, "Sprinkle into wort".  And I swear Nottingham use to say, "Do not aerate".  But it also talks about Lysine so, you know, You didn't say the magic word!

Quote from: http://www.fermentis.com/wp-content/uploads/2012/02/SFA_US05.pdf
rehydration instructions
Sprinkle the yeast in minimum 10 times its weight of sterile water or wort at 27°C ± 3°C (80°F ± 6°F). Leave to rest 15 to 30 minutes.
Gently stir for 30 minutes, and pitch the resultant cream into the fermentation vessel.
Alternatively, pitch the yeast directly in the fermentation vessel providing the temperature of the wort is above 20°C (68°F). 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, then mix the
wort using aeration or by wort addition.

so according to germentis you can go either way but it looks like they prefer water rehydration
Title: Re: Don't make yeast starters from dry yeast? WTF?
Post by: Jimmy K on January 28, 2013, 02:01:18 PM
Yes, Fermentis has instructions for both. I'm pretty sure "Sprinkle onto wort" is the sales line to encourage purchase. And it does work pretty well, but if you want maximum viability (like for a big beer) you really should rehydrate.
Title: Re: Don't make yeast starters from dry yeast? WTF?
Post by: weithman5 on January 28, 2013, 02:47:31 PM
when you sprinkle it into your wort, you really aren't re-hydrating in alcohol though
Title: Re: Don't make yeast starters from dry yeast? WTF?
Post by: Jimmy K on January 28, 2013, 02:53:03 PM
when you sprinkle it into your wort, you really aren't re-hydrating in alcohol though
No, but from what I hear (I haven't asked the yeast personally) is that their cell walls are inactive and some will die from the rush of sugars entering their cells. Once rehydrated in water they can fight the osmotic pressure.
Title: Re: Don't make yeast starters from dry yeast? WTF?
Post by: dimik on January 28, 2013, 02:54:12 PM
I didn't see anyone bring up the main issue (in my opinion). Which is if you make starter with dry yeast, you'll kill about 50-60% of them right off the bat. It is better to rehydrate dry yeast in warm water (35-40*C - 95-104*F) for 15-20 min and then gradually cool and add to wort or starter. This has to do with the fact that dried cells have damaged membranes and need time to rebuild them, "patch the holes", resume membrane transport control, etc. Otherwise they have no control as to what goes in or out of cells. That happens fairly quickly, but still takes a few minutes. Temperature also plays a role. Rehydrating in cool water ~60*F will usually kill about a half of them. Now if you put dry yeast into a starter, the relatively high sugar concentration (yes, even 1.030 is high relative to dry yeast) and hops (if any) will destroy a lot of cells so essentially you'll be raising the starter to get back up to the number of cells that was there to begin with.
Another thing is that dry yeast packets contain approx 200 billion cells, and if you put directly into wort and kill half of them in doing so, there will still be enough cells left to normally ferment your average beer.
Title: Re: Don't make yeast starters from dry yeast? WTF?
Post by: dimik on January 28, 2013, 02:55:07 PM
when you sprinkle it into your wort, you really aren't re-hydrating in alcohol though
No, but from what I hear (I haven't asked the yeast personally) is that their cell walls are inactive and some will die from the rush of sugars entering their cells. Once rehydrated in water they can fight the osmotic pressure.

Hehe. You posted this while I was writing the reply above. :)
Title: Re: Don't make yeast starters from dry yeast? WTF?
Post by: Jimmy K on January 28, 2013, 03:13:40 PM
when you sprinkle it into your wort, you really aren't re-hydrating in alcohol though
No, but from what I hear (I haven't asked the yeast personally) is that their cell walls are inactive and some will die from the rush of sugars entering their cells. Once rehydrated in water they can fight the osmotic pressure.

Hehe. You posted this while I was writing the reply above. :)
I'm a ninja.
Title: Don't make yeast starters from dry yeast? WTF?
Post by: suprchunk on January 29, 2013, 01:36:25 PM
when you sprinkle it into your wort, you really aren't re-hydrating in alcohol though
I think Kai was responding to the person saying that trying to pitch on a stuck fermentation never worked for him/her. Actually, I don't think it, I know. Since he quoted him and all.
Title: Re: Don't make yeast starters from dry yeast? WTF?
Post by: industrialpunk on February 01, 2013, 12:57:16 AM
Here a Danstar yeast expert explains why you rehydrate but DO NOT make a starter:
http://koehlerbeer.com/2008/06/07/rehydrating-dry-yeast-with-dr-clayton-cone/ (http://koehlerbeer.com/2008/06/07/rehydrating-dry-yeast-with-dr-clayton-cone/)
Title: Don't make yeast starters from dry yeast? WTF?
Post by: bluesman on February 01, 2013, 01:31:35 AM
I have to agree with the yeast experts here. Making a starter with dry yeast is not recommended, as it will only deplete the glycol reserves much needed for anaerobic metabolism. Rehydration of the dry yeast is recommended as it allows for rehydration and mitigates destruction of the cell walls during the process.

Dry pitching the yeast will kill a significant percentage of the cells during the rehydration process, because the sugar concentration in the wort has a toxic effect on the yeast. The cell walls are not able to effectively absorb wort. Rehydrating in warm water first allows for a much better potential of survival during fermentation.
Title: Re: Don't make yeast starters from dry yeast? WTF?
Post by: a10t2 on February 01, 2013, 01:40:50 AM
Glycol probably isn't great for the yeast anyway. ;)
Title: Don't make yeast starters from dry yeast? WTF?
Post by: bluesman on February 01, 2013, 01:45:11 AM
Glycol probably isn't great for the yeast anyway. ;)

Only on Sundays. ;)
Title: Re: Don't make yeast starters from dry yeast? WTF?
Post by: jackhorzempa on February 05, 2013, 07:32:42 PM
I didn't see anyone bring up the main issue (in my opinion). Which is if you make starter with dry yeast, you'll kill about 50-60% of them right off the bat. It is better to rehydrate dry yeast in warm water (35-40*C - 95-104*F) for 15-20 min and then gradually cool and add to wort or starter. This has to do with the fact that dried cells have damaged membranes and need time to rebuild them, "patch the holes", resume membrane transport control, etc. Otherwise they have no control as to what goes in or out of cells. That happens fairly quickly, but still takes a few minutes. Temperature also plays a role. Rehydrating in cool water ~60*F will usually kill about a half of them. Now if you put dry yeast into a starter, the relatively high sugar concentration (yes, even 1.030 is high relative to dry yeast) and hops (if any) will destroy a lot of cells so essentially you'll be raising the starter to get back up to the number of cells that was there to begin with.
Another thing is that dry yeast packets contain approx 200 billion cells, and if you put directly into wort and kill half of them in doing so, there will still be enough cells left to normally ferment your average beer.
I think you made an excellent point. Making a starter with dry yeast is indeed detrimental since a lot of the yeast cells will be killed in the process!

Cheers!