# Homebrewers Association | AHA Forum

## General Category => Going Pro => Topic started by: ccfoo242 on July 04, 2013, 02:02:46 AM

Title: Why Plato?
Post by: ccfoo242 on July 04, 2013, 02:02:46 AM
Why is it pro brewers use plato for beginning and ending measurements instead of specific gravity?

Do pro brewers use a different instrument than a hydrometer?
Title: Re: Why Plato?
Post by: jamminbrew on July 04, 2013, 04:12:11 AM
"°Plato = percent extract (or "sugar", although it's not all sugar) by weight in solution. So, 10°P = 10% extract by weight. This makes things easy for brewing calculations.

Specific gravity relates to (instead of weight of extract) the weight of the whole volume of solution relative to an equal volume of water. So, a 1.060 volume of wort is 6% heavier than the same volume of water."

I got this from:
http://www.homebrewtalk.com/f14/plato-vs-specific-gravity-117065/

I hope this helps?

Edit: We use a refractometer during sparge, pre and post-boil, and to ascertain our OG.  Hydrometer to check during fermentation, and FG.
Title: Re: Why Plato?
Post by: dmtaylor on July 04, 2013, 12:33:05 PM
My bet is they still use Plato for a couple of reasons:

1) They've always done it that way for hundreds of years, and

2) In their mind it might be a little easier to deal with than a bunch of ones and decimal points and zeroes.  Just easier to write down and keep track of and so forth than a bunch of extra digits.

To each their own.  I prefer specific gravity because for a 1.060 beer I know I can lop off the 1.0 and add a decimal point to get approximately a 6.0% ABV beer.  But the pros will say, that's easy -- it's a 15 Plato beer, so just multiply by 4 and throw in the decimal point to get the same ABV potential.  Personally I think not having to multiply by 4 makes life a lot easier.  But whatever.
Title: Re: Why Plato?
Post by: cheshirecat on July 04, 2013, 04:07:59 PM
I would also add that it is probably easier on brew day using a couple drops of wort on a refractometer vs filling hydrometer every time you wanted to check the gravity. Less worries about temp etc.

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Title: Re: Why Plato?
Post by: klickitat jim on July 04, 2013, 04:58:58 PM
I'm not sure, but its just 0957 hrs and I haven't woke up yet
Title: Re: Why Plato?
Post by: dmtaylor on July 05, 2013, 02:49:41 PM
I would also add that it is probably easier on brew day using a couple drops of wort on a refractometer vs filling hydrometer every time you wanted to check the gravity. Less worries about temp etc.

Cheshirecat is also right, but this still begs the question: Why couldn't the refractometer manufacturers have their meters read out in units of SG rather than Brix or Plato?  How did they select the standard units?  Maybe it's a wine thing?  But why couldn't wine guys use SG also??

No matter how you look at it, I think it's just people too set in their old ways of doing things.
Title: Re: Why Plato?
Post by: Jimmy K on July 05, 2013, 04:39:34 PM
I says to myself - I'm sure there is a SG refractometer out there. Sure enough - dual scale ...

http://www.amazon.com/Beer-Wort-Wine-Refractometer-Scale/dp/B006GG0TDK (http://www.amazon.com/Beer-Wort-Wine-Refractometer-Scale/dp/B006GG0TDK)

AND IT'S ON SALE FOR \$15 (from \$90). SCORE!!!
Title: Re: Why Plato?
Post by: morticaixavier on July 05, 2013, 04:56:57 PM
I says to myself - I'm sure there is a SG refractometer out there. Sure enough - dual scale ...

http://www.amazon.com/Beer-Wort-Wine-Refractometer-Scale/dp/B006GG0TDK (http://www.amazon.com/Beer-Wort-Wine-Refractometer-Scale/dp/B006GG0TDK)

AND IT'S ON SALE FOR \$15 (from \$90). SCORE!!!

I actually just grabbed one as well. did I  need it? nah but it's a darn good deal
Title: Re: Why Plato?
Post by: dmtaylor on July 05, 2013, 05:40:00 PM
Pretty sweet, HOWEVER.... I considered buying one myself, until I read the reviews that said the SG scale is quite a bit off.  The Brix scale reads right though apparently.  But if it can't read the SG scale right, then I don't want one.
Title: Re: Why Plato?
Post by: Jimmy K on July 05, 2013, 05:46:39 PM
Technically, I think that's because a refractometer can't directly read SG. And the problem is the relationship between SG and Plato are not perfectly linear. For the same reason, a hydrometer can't directly read Plato.
Title: Re: Why Plato?
Post by: punatic on July 05, 2013, 07:11:10 PM
Because Plato was way smarter and much more philisophical than Specfic Gravity and Mr. Brix.  I mean Plato's teacher was Socrates for cryin' out loud!   That just screams beer!  :o
Title: Re: Why Plato?
Post by: klickitat jim on July 05, 2013, 07:13:56 PM
Pronounced So-Crates and he hated Say-Zon
Title: Re: Why Plato?
Post by: ccfoo242 on July 05, 2013, 11:07:07 PM
Technically, I think that's because a refractometer can't directly read SG. And the problem is the relationship between SG and Plato are not perfectly linear. For the same reason, a hydrometer can't directly read Plato.

So when a brewery gives starting and finishing plato, which instrument gives them that? Refractometers give degrees Brix and hydrometers give specific gravity. What gives plato?
Title: Re: Why Plato?
Post by: punatic on July 05, 2013, 11:07:36 PM
Pronounced So-Crates and he hated Say-Zon
But he loved Ply Knee the Elder!   ::)
Title: Re: Why Plato?
Post by: Pawtucket Patriot on July 06, 2013, 12:30:24 AM
Technically, I think that's because a refractometer can't directly read SG. And the problem is the relationship between SG and Plato are not perfectly linear. For the same reason, a hydrometer can't directly read Plato.

So when a brewery gives starting and finishing plato, which instrument gives them that? Refractometers give degrees Brix and hydrometers give specific gravity. What gives plato?

Brix = Plato
Title: Re: Why Plato?
Post by: Thirsty_Monk on July 06, 2013, 12:58:09 AM
Technically, I think that's because a refractometer can't directly read SG. And the problem is the relationship between SG and Plato are not perfectly linear. For the same reason, a hydrometer can't directly read Plato.

So when a brewery gives starting and finishing plato, which instrument gives them that? Refractometers give degrees Brix and hydrometers give specific gravity. What gives plato?

Brix = Plato
Acutely that s not correct.
There is 1.04 correction factor.
I think it has to do with what kind of sugar it is.

I use hydrometer with Plato scale and thermometer with adjustment factor.
I have one for low range (0-9) and one for mid range (8-16)
I should also buy the high range but I do not brew too many beers over 16 Plato.
I like this hydrometer better then refractometer.
I think it is more accurate.
I measure only Last runnings and wort after cooling.
Title: Re: Why Plato?
Post by: a10t2 on July 06, 2013, 03:03:46 AM
Brix = Plato
Acutely that s not correct.

They're different, but the difference is so small it doesn't matter at all in brewing. 1.040 SG is 9.99325 °Bx or 9.99359 °P.

I think Plato is more intuitive. It scales linearly, and one "unit" is a significant variation for brewing purposes. It's also shorter/easier to read and write, which reduces the likelihood of mistakes.
Title: Re: Why Plato?
Post by: reverseapachemaster on July 06, 2013, 05:42:42 PM
My understanding -- and this is probably some or all incorrect -- is that plato is used a lot in the professional brewing literature from continental Europe while gravity was more of an English preference. When brewers in the US learned to brew it was from continental literature but homebrewers adopted texts from English brewers which carried gravity forward into American homebrewing. I don't know where I picked up that story but it seems to have some potential truth to it.
Title: Re: Why Plato?
Post by: ccfoo242 on July 06, 2013, 08:57:44 PM
So what's used to measure the finishing Plato? I know they can use a refractometer only if they use a formula like Sean's. Sorry to seem dense. If they use a hydrometer then wouldn't that require them to convert to Plato?

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Title: Re: Why Plato?
Post by: denny on July 06, 2013, 09:35:00 PM
So what's used to measure the finishing Plato? I know they can use a refractometer only if they use a formula like Sean's. Sorry to seem dense. If they use a hydrometer then wouldn't that require them to convert to Plato?

Sent from the future using Tapatalk

My hydrometer reads in Brix, Plato, and SG.
Title: Re: Why Plato?
Post by: Kaiser on July 06, 2013, 09:40:07 PM
I believe it's because Plato is more precise than sg when it comes to attenuation calculations, for example. Also, most of the brewing calculations are based on Plato or a similar measure of wort solids.

Sg works well enough and was picked up by home brewers. Sg based brewing calculations also originate in UK brewing if I'm not mistaken.

When I toured AB a while back I noticed extract displays in Balling.

Kai

Title: Re: Why Plato?
Post by: denny on July 06, 2013, 10:42:47 PM
I believe it's because Plato is more precise than sg when it comes to attenuation calculations, for example. Also, most of the brewing calculations are based on Plato or a similar measure of wort solids.

Sg works well enough and was picked up by home brewers. Sg based brewing calculations also originate in UK brewing if I'm not mistaken.

When I toured AB a while back I noticed extract displays in Balling.

Kai

Good to see you posting again, Kai.
Title: Re: Why Plato?
Post by: Kaiser on July 07, 2013, 12:52:07 AM

Good to see you posting again, Kai.

Let's see how much time I can find for the forums.

Kai

Title: Re: Why Plato?
Post by: denny on July 07, 2013, 01:06:57 AM

Good to see you posting again, Kai.

Let's see how much time I can find for the forums.

Kai

Any is better than none!
Title: Re: Why Plato?
Post by: bluesman on July 08, 2013, 02:23:07 AM

Good to see you posting again, Kai.

Let's see how much time I can find for the forums.

Kai

You have to make time Kai.

Happy to see you back. Your feedback is appreciated by many, including me.
Title: Re: Why Plato?
Post by: hopfenundmalz on July 08, 2013, 12:58:40 PM

Good to see you posting again, Kai.

Let's see how much time I can find for the forums.

Kai
I too appreciate your insights and research posts.

One of the downsides of a 3500 person conference, is that you don't always get a chance to talk to people. I saw Kai across a crowded seminar room on Saturday, and did not see him again.
Title: Re: Why Plato?
Post by: Kaiser on July 09, 2013, 02:46:20 AM
Thanks.

I should be able to find some time. You can also email me if you feel you need my input on a topic.

The NHC had become big. I wonder how much larger it can get.

Kai
Title: Re: Why Plato?
Post by: hopfenundmalz on July 09, 2013, 09:25:00 AM
Thanks.

I should be able to find some time. You can also email me if you feel you need my input on a topic.

The NHC had become big. I wonder how much larger it can get.

Kai
4000 next year is what they are working on.
Title: Re: Why Plato?
Post by: drjones on July 09, 2013, 04:00:20 PM
Quote
I says to myself - I'm sure there is a SG refractometer out there. Sure enough - dual scale ...

http://www.amazon.com/Beer-Wort-Wine-Refractometer-Scale/dp/B006GG0TDK

AND IT'S ON SALE FOR \$15 (from \$90). SCORE!!!

They are going for \$23 now - still way less than I paid just a few months ago.  If you don't have a refractometer, there is no more excuse not to.  Maybe it's overkill, but I love taking regular readings off my sparge runoff, from the fermenter, etc. a drop at a time.  Besides, the geek factor will bring oohs and aahs from your brew day audience.  That alone is worth the \$23!  White lab coat anyone?
Title: Re: Why Plato?
Post by: denny on July 09, 2013, 04:59:51 PM
Thanks.

I should be able to find some time. You can also email me if you feel you need my input on a topic.

The NHC had become big. I wonder how much larger it can get.

Kai
4000 next year is what they are working on.

Yeah, that's kinda scary....
Title: Re: Why Plato?
Post by: Kaiser on July 09, 2013, 05:02:11 PM
Make sure to check the accuracy of any bargain model. There is not much in the optics that can go wrong but the scale could be put off whack. Also check if the as atc function works. Mine doesn't.

Kai
Title: Re: Why Plato?
Post by: Jimmy K on July 09, 2013, 07:28:07 PM
4000 next year is what they are working on.

Yeah, that's kinda scary....

I hope there are more than 4 concurrent sessions. Those rooms were too big.