ajdelange

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Join Date:

08-06-2010

Last Activity:

07-30-2015 9:05 PM

Likes Given: 31

1029 Likes on 814 Posts 

    ABOUT ME

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

LATEST ACTIVITY

  • Posted in thread: What would happen if you boiled beer? on 07-30-2015 at 08:59 PM
    I want to correct a misconception that is propagated in this thread, that ethanol, having lower
    boiling point than water, will evaporate off before boil.That is not true. It is true. Check up
    on Raoul...

  • Posted in thread: What would happen if you boiled beer? on 07-30-2015 at 05:27 PM
    what would happen if you boiled your finished beer? We do this all the time when we are
    assaying acohol and determining true extract. The result is a foul smelling, dark soup of
    precipitated protein. ...

  • Posted in thread: Construct a dry food grade pH buffer on 07-30-2015 at 05:22 PM
    ...you cannot adequately buffer a mash to a reasonable pH using phosphate buffers ....Some more
    reflection on this subject has led me to think that while the statement above is certainly true
    with res...

  • Posted in thread: Ward lab results - St. Louis County, MO on 07-30-2015 at 02:08 PM
    The corrected numbers are much better but they are still off a small amount in the carbonate
    (more like 11) and bicarbonate (33) based on the reported alkalinity. Interestingly enough
    those would give...

  • Posted in thread: US 220V and European 220v on 07-30-2015 at 01:33 PM
    My guess (though I've never taken one apart) is that the power lines come into a bridge
    followed by DC/DC converters for whatever voltages the individual circuits need. Thus,
    conceptually and if my hy...

  • Posted in thread: US 220V and European 220v on 07-29-2015 at 11:30 PM
    It's significant if you are using the neutral for anything in the US spec circuit as a
    significant number of the controller circuits posted here do. e.g. powering the PID or anything
    else from one hot...

  • Posted in thread: US 220V and European 220v on 07-29-2015 at 01:43 PM
    Much more importantly, US 230V is two-phase with a neutral close to ground between the two hot
    phases, and EU 230V is single-phase with one hot wire and one neutral. That's not significant
    at all. 220...

  • Posted in thread: US 220V and European 220v on 07-29-2015 at 01:08 PM
    the MyPin is microcontroller based therefore timing is 100% likely to be based on the crystal
    running the micro NOT the frequency of the ac voltage as the MyPin can probably run anything
    from 85-220V ...

  • Posted in thread: 380V water heater element running with 220V to reduce power? on 07-29-2015 at 03:26 AM
    You can put a power diode in series with the element so that it only conducts during one half
    of the cycle thus producing half the usual power or about 1500 W.

  • Posted in thread: How to calculate how much top up water to add to reach desired gravity? on 07-29-2015 at 12:15 AM
    I actually know what my final gravity should be (1.050) and what my capacity is (I can brew 9
    liters), and I wanna top it up with 6 liters of water to reach a final size of 15 liters. So,
    all I need t...

1 COMMENTS
Posted: 
February 8, 2014  •  08:08 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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