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Main
Date: 12 Dec 2006 15:27:22
From: John LaBella
Subject: SG Curioisty - caution Noob Question
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I am on my second kit beer an Irish stout.
I have been in the primary fermentation stage. Initial SG was 1.038
On Saturday SG was 1.012 (six days since start of brew)
On Sunday SG was 1.008
Yesterday it was 1.010
Fermenter is in my heated basement Has a lid with airlock. (Tasted quite
nice (I mean I couldn't just chuck the portion I tested the SG).
Should I wait more days or should I bottle now?
THanks
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Date: 12 Dec 2006 09:23:31
From: Jeff
Subject: Re: SG Curioisty - caution Noob Question
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John LaBella wrote:
> On Saturday SG was 1.012 (six days since start of brew)
> On Sunday SG was 1.008
> Yesterday it was 1.010
What Dan said - one of your readings wasn't right. You should not go up
in SG, only down during fermentation. Don't forget to adjust for
temperature (you mentioned heated basement) and also watch for bubbles
on the hydrometer and make sure it's free floating. I believe you are
supposed to read it at the point that the liquid ramps up to the
hydrometer shaft - at the top of the ramp take a level sighting.
And again as Dan said, there'd be no problems in just waiting. Keep
taking readings and you'll figure out what went wrong to cause the
reading to go up.
The rule of thumb is to get 3 readings with no change over the course
of 3 or more days and then bottle.
--Jeff
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Date: 12 Dec 2006 20:01:42
From: Tony Verhulst
Subject: Re: SG Curioisty - caution Noob Question
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Jeff wrote:
> ...I believe you are
> supposed to read it at the point that the liquid ramps up to the
> hydrometer shaft - at the top of the ramp take a level sighting.
No. You always read at the bottom of a concave meniscus.
http://en.wikipedia.org/wiki/Meniscus
Tony V.
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Date: 12 Dec 2006 20:18:05
From: Ed Edelenbos
Subject: Re: SG Curioisty - caution Noob Question
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"Tony Verhulst" <no@thankyou.com > wrote in message
news:SImdnea48cxqzeLYnZ2dnUVZ_oPinZ2d@comcast.com...
> Jeff wrote:
>> ...I believe you are
>> supposed to read it at the point that the liquid ramps up to the
>> hydrometer shaft - at the top of the ramp take a level sighting.
>
>
> No. You always read at the bottom of a concave meniscus.
> http://en.wikipedia.org/wiki/Meniscus
>
> Tony V.
Hmmm.... the instructions for mine even has a handy picture showing how to
read the top of the concave meniscus.
I guess it depends on the calibration procedure used. One way to check
would be to take some water at the right temp (68F for the one I have though
60F seems to be the most common I've seen) and do a test reading.
Ed
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Date: 12 Dec 2006 19:03:59
From: The Artist Formerly Known as Kap'n Salty
Subject: Re: SG Curioisty - caution Noob Question
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Tony Verhulst wrote:
> Jeff wrote:
>> ...I believe you are
>> supposed to read it at the point that the liquid ramps up to the
>> hydrometer shaft - at the top of the ramp take a level sighting.
>
>
> No. You always read at the bottom of a concave meniscus.
> http://en.wikipedia.org/wiki/Meniscus
But isn't a hydrometer meniscus always convex? Mine are, anyway...
--
(Replies: cleanse my address of the Mark of the Beast!)
Teleoperate a roving mobile robot from the web:
http://www.swampgas.com/robotics/rover.html
Coauthor with Dennis Clark of "Building Robot Drive Trains".
Buy several copies today!
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Date: 13 Dec 2006 01:14:52
From: Bart Goddard
Subject: Re: SG Curioisty - caution Noob Question
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mikey666@666swampgas.666com wrote:
> Tony Verhulst wrote:
>> Jeff wrote:
>>> ...I believe you are
>>> supposed to read it at the point that the liquid ramps up to the
>>> hydrometer shaft - at the top of the ramp take a level sighting.
>>
>>
>> No. You always read at the bottom of a concave meniscus.
>> http://en.wikipedia.org/wiki/Meniscus
>
> But isn't a hydrometer meniscus always convex? Mine are, anyway...
Depends on which side you're standing on.
And since the only thing we're really concerned with is
potential, it doesn't matter which way you do it, as long as
you do it the same way both (or every) times.
Bart
--
The man without a .sig
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Date: 13 Dec 2006 20:57:23
From: John 'Shaggy' Kolesar
Subject: Re: SG Curioisty - caution Noob Question
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On 13 Dec 2006 01:14:52 GMT, <goddardbe@netscape.net > wrote:
> And since the only thing we're really concerned with is
> potential, it doesn't matter which way you do it, as long as
> you do it the same way both (or every) times.
Yeah, just pick one and stay consistent.
John.
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Date: 13 Dec 2006 08:50:07
From: MattMika
Subject: Re: SG Curioisty - caution Noob Question
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On Tue, 12 Dec 2006 20:01:42 -0500, Tony Verhulst <no@thankyou.com >
wrote:
>Jeff wrote:
>> ...I believe you are
>> supposed to read it at the point that the liquid ramps up to the
>> hydrometer shaft - at the top of the ramp take a level sighting.
>
>
>No. You always read at the bottom of a concave meniscus.
>http://en.wikipedia.org/wiki/Meniscus
>
>Tony V.
I picked up a new hydrometer last night and sure enough, at least on
this one, you read the top of the meniscus. One would figure the
hydrometer industry would align itself with known standards, but I
guess not.
And I guess my brews have all been recorded as a point or two above
what they actually were, unless of course the last hydrometer read
from the bottom of the miniscus. Either way not much of a
difference...
MattMika
"If you love wealth more than liberty, the
tranquillity of servitude better than the
animating contest of freedom, depart from us in
peace. We ask not your counsel or your arms.
Crouch down and lick the hand that feeds you.
May your chains rest lightly upon you and may
posterity forget that you were our countrymen."
- Samuel Adams
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Date: 13 Dec 2006 11:07:07
From: Ed Edelenbos
Subject: Re: SG Curioisty - caution Noob Question
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"MattMika" <mattmika@hotmail.com > wrote in message
news:sv70o2thbs9npsi97upnolfjis81pnfnbb@4ax.com...
> On Tue, 12 Dec 2006 20:01:42 -0500, Tony Verhulst <no@thankyou.com>
> wrote:
>
>>Jeff wrote:
>>> ...I believe you are
>>> supposed to read it at the point that the liquid ramps up to the
>>> hydrometer shaft - at the top of the ramp take a level sighting.
>>
>>
>>No. You always read at the bottom of a concave meniscus.
>>http://en.wikipedia.org/wiki/Meniscus
>>
>>Tony V.
>
> I picked up a new hydrometer last night and sure enough, at least on
> this one, you read the top of the meniscus. One would figure the
> hydrometer industry would align itself with known standards, but I
> guess not.
>
I think the basis is that typically when reading a meniscus, it is a
volumetric measurement... i.e., the vessel is calibrated to give a reading
on the volume of what it contains. Varying surface tensions could cause
some adhesion to the sides of the vessel and cause a meniscus. The logical
reading would be the bottom of the (concave) meniscus (and the top of a
convex meniscus) because it is only present at the sides and not
representative of the material in the vessel. And, different materials will
have different menisci (is that the way that would be spelled?).
A hydrometer is a direct reading instrument and it's scale can be set for
either... and in the case of our (typically) brewing specific instruments,
broad assumptions (about the shape of the meniscus) can be made about the
material that will be measured.
Ed
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Date: 12 Dec 2006 15:05:33
From: MattMika
Subject: Re: SG Curioisty - caution Noob Question
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On 12 Dec 2006 09:23:31 -0800, "Jeff" <jjhenze@gmail.com > wrote:
>I believe you are
>supposed to read it at the point that the liquid ramps up to the
>hydrometer shaft - at the top of the ramp take a level sighting.
Hmm, I've always done the opposite. I read from the bottom of the
'ramp.' In basic chemistry I was taught to read from the bottom and
ignore the capillary action, the upper part of the 'ramp.' But that is
for volumetric measurements in pipettes and such.
The difference between the two would seem minute, though.
MattMika
"If you love wealth more than liberty, the
tranquillity of servitude better than the
animating contest of freedom, depart from us in
peace. We ask not your counsel or your arms.
Crouch down and lick the hand that feeds you.
May your chains rest lightly upon you and may
posterity forget that you were our countrymen."
- Samuel Adams
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Date: 12 Dec 2006 17:33:50
From: Ed Edelenbos
Subject: Re: SG Curioisty - caution Noob Question
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"MattMika" <mattmika@hotmail.com > wrote in message
news:n59un2dq80uucktaa8a2335o9msfbac0r7@4ax.com...
> On 12 Dec 2006 09:23:31 -0800, "Jeff" <jjhenze@gmail.com> wrote:
>
>>I believe you are
>>supposed to read it at the point that the liquid ramps up to the
>>hydrometer shaft - at the top of the ramp take a level sighting.
>
> Hmm, I've always done the opposite. I read from the bottom of the
> 'ramp.' In basic chemistry I was taught to read from the bottom and
> ignore the capillary action, the upper part of the 'ramp.' But that is
> for volumetric measurements in pipettes and such.
>
> The difference between the two would seem minute, though.
>
> MattMika
>
Most hydrometers I've seen, say (in the instructions) to read the top of the
meniscus. It's about 2 points difference between the top and bottom with
mine. If I ever get to the point where my calculations are that critical,
I'll worry about it. (grin) I think that if the reading is consistently
taken using the same part of the meniscus, the (relative) information will
be valid enough.
Getting back to the OP, if it is a stout that started at 1.038 and got to
1.010, my bet is that it is done. Giving it another 3-5 days (preferably in
a secondary) for most of the yeast to settle out would be a good idea...
unless you are good at and don't mind decanting from the bottles.
Ed
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Date: 12 Dec 2006 16:48:31
From: MattMika
Subject: Re: SG Curioisty - caution Noob Question
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On Tue, 12 Dec 2006 17:33:50 -0500, "Ed Edelenbos"
<eded@spookeasy.net > wrote:
>
>"MattMika" <mattmika@hotmail.com> wrote in message
>news:n59un2dq80uucktaa8a2335o9msfbac0r7@4ax.com...
>> On 12 Dec 2006 09:23:31 -0800, "Jeff" <jjhenze@gmail.com> wrote:
>>
>>>I believe you are
>>>supposed to read it at the point that the liquid ramps up to the
>>>hydrometer shaft - at the top of the ramp take a level sighting.
>>
>> Hmm, I've always done the opposite. I read from the bottom of the
>> 'ramp.' In basic chemistry I was taught to read from the bottom and
>> ignore the capillary action, the upper part of the 'ramp.' But that is
>> for volumetric measurements in pipettes and such.
>>
>> The difference between the two would seem minute, though.
>>
>> MattMika
>>
>
>Most hydrometers I've seen, say (in the instructions) to read the top of the
>meniscus. It's about 2 points difference between the top and bottom with
>mine. If I ever get to the point where my calculations are that critical,
>I'll worry about it. (grin) I think that if the reading is consistently
>taken using the same part of the meniscus, the (relative) information will
>be valid enough.
>
>Ed
>
I dont remember reading that on mine, but I may have not read the
directions all that carefull or at all ;). Anyway I finally broke it
after 5+ yrs. so I'll be looking for that on the new one I'm picking
up tonight!
"If you love wealth more than liberty, the
tranquillity of servitude better than the
animating contest of freedom, depart from us in
peace. We ask not your counsel or your arms.
Crouch down and lick the hand that feeds you.
May your chains rest lightly upon you and may
posterity forget that you were our countrymen."
- Samuel Adams
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Date: 12 Dec 2006 21:33:34
From:
Subject: Re: SG Curioisty - caution Noob Question
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: What Dan said - one of your readings wasn't right. You should not go up
: in SG, only down during fermentation. Don't forget to adjust for
: temperature (you mentioned heated basement) and also watch for bubbles
: on the hydrometer and make sure it's free floating. I believe you are
: supposed to read it at the point that the liquid ramps up to the
: hydrometer shaft - at the top of the ramp take a level sighting.
Also, if you poured beer/wort over the top of the hydrometer, the wetting of
the top part can cause a lower reading. Of course it depends on how much of it sticks
out of the water (how much wetness is on it). By drying the top (usually with my
shirt... :), a FG will often change by a point, and an OG of 1.070-ish will change by
3-4.
-Cory
--
*************************************************************************
* Cory Papenfuss, Ph.D., PPSEL-IA *
* Electrical Engineering *
* Virginia Polytechnic Institute and State University *
*************************************************************************
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Date: 12 Dec 2006 10:47:45
From: Dan Logcher
Subject: Re: SG Curioisty - caution Noob Question
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John LaBella wrote:
> I am on my second kit beer an Irish stout.
>
> I have been in the primary fermentation stage. Initial SG was 1.038
>
> On Saturday SG was 1.012 (six days since start of brew)
> On Sunday SG was 1.008
> Yesterday it was 1.010
Could have been an bad reading on Sunday.. Hydrometers are a pain in
the ass sometimes.
> Fermenter is in my heated basement Has a lid with airlock. (Tasted quite
> nice (I mean I couldn't just chuck the portion I tested the SG).
Of course.. you must taste it.
> Should I wait more days or should I bottle now?
Wouldn't hurt to wait.
--
Dan
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Date: 13 Dec 2006 09:55:30
From:
Subject: Re: SG Curioisty - caution Noob Question
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John LaBella wrote:
> I am on my second kit beer an Irish stout.
>
> I have been in the primary fermentation stage. Initial SG was 1.038
>
> On Saturday SG was 1.012 (six days since start of brew)
> On Sunday SG was 1.008
> Yesterday it was 1.010
>
> Fermenter is in my heated basement Has a lid with airlock. (Tasted quite
> nice (I mean I couldn't just chuck the portion I tested the SG).
>
> Should I wait more days or should I bottle now?
>
> THanks
( puts on asbestos flame-retardant skivvies )
After reading all of these posts it should be obvious that the best
answer is to "buy a temperature correcting refractometer".
:-)
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Date: 13 Dec 2006 06:53:11
From: Chris
Subject: Re: SG Curioisty - caution Noob Question
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On Dec 12, 7:01 pm, Tony Verhulst <n...@thankyou.com > wrote:
> Jeff wrote:
> > ...I believe you are
> > supposed to read it at the point that the liquid ramps up to the
> > hydrometer shaft - at the top of the ramp take a level sighting.No. You always read at the bottom of a concave meniscus.http://en.wikipedia.org/wiki/Meniscus
>
> Tony V.
If the manufacture built the hydrometer with the scale inside set for
reading at the top of the meniscus (granted this is not the standard
for chemestry) and the manufactures instrunctions seem to suggest this,
then top it is.
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Date: 13 Dec 2006 20:54:06
From: John 'Shaggy' Kolesar
Subject: Re: SG Curioisty - caution Noob Question
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On Tue, 12 Dec 2006 15:27:22 GMT, <blank@dev.com > wrote:
> I am on my second kit beer an Irish stout.
>
> I have been in the primary fermentation stage. Initial SG was 1.038
>
> On Saturday SG was 1.012 (six days since start of brew)
> On Sunday SG was 1.008
> Yesterday it was 1.010
I don't think the SG actually went up by .002 points. Are you sure you
measured that one correctly?
> Fermenter is in my heated basement Has a lid with airlock. (Tasted quite
> nice (I mean I couldn't just chuck the portion I tested the SG).
>
> Should I wait more days or should I bottle now?
It's probably done, but make sure that the SG stops changing before you
bottle. IOW, take two readings a couple days apart. If it's the same
SG for both readings, then it's stopped changing. As long as it's
reasonable for a FG, then you are ready to bottle. Note that waiting
too long will not hurt anything, but not waiting long enough is a bad
idea. When in doubt, give it some extra time.
John.
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