Author Topic: Vindication for us non-rehydrators  (Read 3705 times)

Offline a10t2

  • Official Poobah of No Life.
  • *
  • Posts: 4694
  • Ask me why I don't like Chico!
    • SeanTerrill.com
Re: Vindication for us non-rehydrators
« Reply #45 on: June 19, 2018, 02:18:33 AM »
But if you're doing a side-by-side, tracking fermentation and sensory analysis will be interesting.  It's just possible the counts are a red herring.  (I'm thinking of the arguments pertaining to vitality starters.)
EDIT  and full disclosure, I've never tried the vitality method, always been a conventional, pitch-rate obsessed brewer.  But I keep finding myself surprised these days.

I'll try to get a decent sized triangle test together as well; the problem is I'm adjacent to the middle of nowhere and I know my own palate is wrong often enough that I won't trust it for that kind of thing.

And I can definitely relate to rethinking the pitching rate obsession; I massively under pitched a batch recently and while there are definite differences it's far from undrinkable (have a pint in hand now, in fact).
Sent from my Microsoft Bob

Beer is like porn. You can buy it, but it's more fun to make your own.
Refractometer Calculator | Batch Sparging Calculator | Two Mile Brewing Co.

Offline Robert

  • Official Poobah of No Life.
  • *
  • Posts: 4214
Re: Vindication for us non-rehydrators
« Reply #46 on: June 20, 2018, 11:17:04 PM »
Further reading on Fermentis website (Q&A):

•They say that direct pitching  presents the potential for a maximum loss of viable cells of 3-6%.

•They also say that while the labelling/TDS gives a count of ">6B" viable cells/g, at packaging there are 10B viable cells/g.

Very helpful for determining a pitch rate. (Looks like I guessed my way into hitting it just about right anyway this time.)
Rob Stein
Akron, Ohio

I'd rather have questions I can't answer than answers I can't question.

Offline Saccharomyces

  • Brewer
  • ****
  • Posts: 377
Re: Vindication for us non-rehydrators
« Reply #47 on: July 29, 2018, 12:44:45 PM »
Interestingly, their technical data sheet suggests an alternate method:  sprinkle on top of wort in the fermenter, leave 30 minutes, then aerate to mix.  Maybe I'll add the aeration step.  Or not.

In reality, unless one is seriously underpitching, wort does not need to be aerated when using dry yeast.  Dry yeast is grown under aerobic conditions below the Crabtree threshold in a bioreactor.  It is a very efficient way to propagate yeast cells because yeast cells produce more energy from the medium using the aerobic metabolic pathway instead of the anaerobic metabolic pathway.  The bonus is that the cells come out of the bioreactor with fully charged ergosterol and unsaturated fatty acids reserves.  The reason why we aerate wort is to provide O2 for the synthesization of these compounds during the lag phase.

Offline BrewBama

  • Official Poobah of No Life.
  • *
  • Posts: 3763
Re: Vindication for us non-rehydrators
« Reply #48 on: July 29, 2018, 01:15:49 PM »
Interestingly, their technical data sheet suggests an alternate method:  sprinkle on top of wort in the fermenter, leave 30 minutes, then aerate to mix.  Maybe I'll add the aeration step.  Or not.

In reality, unless one is seriously underpitching, wort does not need to be aerated when using dry yeast.  Dry yeast is grown under aerobic conditions below the Crabtree threshold in a bioreactor.  It is a very efficient way to propagate yeast cells because yeast cells produce more energy from the medium using the aerobic metabolic pathway instead of the anaerobic metabolic pathway.  The bonus is that the cells come out of the bioreactor with fully charged ergosterol and unsaturated fatty acids reserves.  The reason why we aerate wort is to provide O2 for the synthesization of these compounds during the lag phase.

...and this is why we missed you. Cheers!


Sent from my iPad using Tapatalk
“From man’s sweat and God’s love, beer came into the world.” — St. Arnold

Brewed in the Tennessee Valley. Rocket City — Huntsville AL

Offline Robert

  • Official Poobah of No Life.
  • *
  • Posts: 4214
Re: Vindication for us non-rehydrators
« Reply #49 on: July 29, 2018, 03:19:03 PM »
Update:  I figured out their suggestion of aeration was just a way of introducing agitation to mix in a commercial size fermenter.  The alternative given is to fill the cone, wait 30 minutes, and fill the remainder.  I did the aeration mixing method once, and on homebrew scale it is a useless (as Sacch. explains) complication.  Rocking my Speidel does the trick.
Rob Stein
Akron, Ohio

I'd rather have questions I can't answer than answers I can't question.