ajdelange

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Join Date:

08-05-2010

Last Activity:

05-05-2015 12:15 PM

Likes Given: 24

906 Likes on 732 Posts 

    ABOUT ME

  • Retired
  • Baroque, early Classical
  • BURP, AHA, ASBC, MBAA
  • Male
  • Married
  • McLean/Ogden
  • Virginia/Quebec

LATEST ACTIVITY

  • Posted in thread: Gravity to Molarity question on 05-05-2015 at 03:55 PM
    The reason the Kaiser established the Plato Kommission is because the Brix scale was known to
    be innacurate in the 4th decimal place and beyond. Plato did exactly what Brix did, i.e.
    measure the speci...

  • Posted in thread: Gravity to Molarity question on 05-05-2015 at 01:06 PM
    1000g/342g/mol = 2.92 mol.I think you have missed the point. It is not a question as to what
    any particular sugar concentration calculates out to but rather as to how to interpret that. I
    am not refer...

  • Posted in thread: Gravity to Molarity question on 05-05-2015 at 12:03 PM
    I left a whole lot of important stuff out last night and have gone back and edited it in.
    Perhaps the most important thing, important enough to justify a separate post, is that you
    can't compute the m...

  • Posted in thread: Gravity to Molarity question on 05-05-2015 at 04:20 AM
    Degrees Plato is the strength of a sucrose solution of the same specific gravity as the
    wort/beer by weight in percent. Thus a 10 °P wort has the same specific gravity (1.0403) as a
    sucrose solution o...

  • Posted in thread: Mineral taste from gypsum even at low levels. on 05-04-2015 at 03:23 PM
    No, you will be lowering it. This is not a bad thing.

  • Posted in thread: Sulfate to Chloride Ratio on 05-03-2015 at 07:10 PM
    This is another proposed sticky intended to relieve my typing burden as it is something that is
    mentioned quite a lot. The intent is not to convince you that you should or shouldn't rely on
    this ratio...

  • Posted in thread: Water Question on 05-03-2015 at 02:37 PM
    Your sulfate to chloride ratio is 1.77 to 1 , I would bump it up a little to 2:1 or 2.5:1 to
    accent bitterness. The higher end will will also make the beer drier if you like that.
    Ca-110ppm, Mg-18ppm,...

  • Posted in thread: PID vs Thermocouple on 05-03-2015 at 02:24 PM
    I guess I'd be reluctant to put a $2.50 temperature sensor in my system simply on the basis of
    "The bitterness of poor quality remains long after the sweetness of low price is forgotten."
    but an even ...

  • Posted in thread: Brewing water for COFFEE on 05-02-2015 at 07:06 PM
    This Jim S guy doesn't seem to be much of an expert. His taste test (non-scientific note
    taking) and recommendation to not bother filtering your tap water hints that he's stuck in the
    weeds, missing t...

  • Posted in thread: Mineral taste from gypsum even at low levels. on 05-02-2015 at 03:24 PM
    You have the opportunity to learn two things here.The first is that personal taste is a bigger
    factor than most people think even though that should be obvious. You don't like minerally
    beer. Don't us...

1 COMMENTS
Posted: 
February 8, 2014  •  02:08 AM
Yeast starters generally need to be stepped up to a size appropriate for 10 gal batch pitching. But I've been researching the reason for this. It seems to me, that if the yeast needs can be anticipated and met for the whole starter size, then this step-up procedure could be eliminated. The most obvious delta (to me) across the fermentation is pH. Internally, yeast maintain pH at 5.0-5.8. Dissolved CO2, excreted acids, and cell H+ transport continously increase H+ concentration, decreasing pH. There needs to be a pH delta across the cell wall for maltose influx. So this is why yeast act to decrease pH in external medium. But they don't appear to be able to shut that process off (at least, completely) and so can acidify mediums that aren't well buffered right down and out of their operating window. Looks like best pH is mid-4's to 5.0 or so. Now, pitching a starter with too little yeast means that they can't quickly acidify the wort down to optimum pH levels. And then, even if they can, such a large amount of growth causes over-acidificaiton and floccing before full attenuation. Since this is a starter and we intend to decant the 'beer' before pitching, can't we introduce a buffer into the wort before fermentation? The buffer would hold pH around 4.5-5.0. The yeast would be presented with optimum pH from start to finish, ensuring full attenuation with any size starter, with any size innoculation. What think ye? Any recommendations for acid-salt-alkaline combinations for buffers?
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