Are original gravity and starting gravity the same thing? . I have been reading up alot and understand nearly all about all grain brewing, but some articles are slightly confusing where gravity is mentioned. Do you read O.G. with the first runnings off the mash tun or once all the wort is collected for boil.
Is the starting gravity the reading you take after the boil, or is it vice versa?
I have only ever done kits and am venturing into all grain, and would like to be clued up before I start.
many thanks..
gravity
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jaroporter
- Drunk as a Skunk
- Posts: 996
- Joined: Sat Jul 21, 2012 11:12 pm
- Location: Garden of England
Re: gravity
hey, sometimes people use different terms for the same thing, and sometimes terms are used incorrectly. Original Gravity (OG) is usually a reference point for the gravity at the start of fermentation, and is paired with Final Gravity (FG) for use in recipes and to calculate alcohol content. starting gravity would reasonably be interchangeable with OG. perhaps some of the confusion with it is that Specific Gravity (SG) refers to the gravity of a liquid at any time, so first runnings, second runnings, mid boil, pre-fermentation, battery acid, whatever.
it definitely helps to be well clued-up before diving in, but don't worry too much with hitting those SGs at every corner for the first few brews. same with kits, the OG and FG will tell you the important information
good luck with the first brew!
it definitely helps to be well clued-up before diving in, but don't worry too much with hitting those SGs at every corner for the first few brews. same with kits, the OG and FG will tell you the important information
good luck with the first brew!dazzled, doused in gin..
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Rick_UK
Re: gravity
Yes the key reading is the one at the end of the boil when the wort has cooled. I've always called this the OG. The FG is at the end of fermentation and the difference between the 2 tells you the attenuation from which you can calculate the alcohol content. A hydrometer just measures the density of a liquid - in brewing its the amount of sugar which increases the density hence the drop in gravity as the sugars are converted to alcohol by the yeastie beasties.
Rick
Rick
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mk1paggy
Re: gravity
Ty rick, I knew that from making kits. I was getting confused from reading up about recipe formulation and brewing efficiency. Where ppl would call the same thing different things. Im pretty sure I understand it now, I hope lol. I read a malting article which was very detailed explaining all about srm lovibond ebc , yeild percentage ect how each type of ingredient gets it's sg value.
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Blackjack
Re: gravity
SG, Specific Gravity
The generic term for all readings of gravity
OG, Original Gravity
The gravity of a wort after all processing ( liquoring up/liquoring down etc ) and prior to but ready for the introduction of yeast for fermentation.
FG, Final Gravity
An unofficial term, however it is commonly understood and used to indicate the gravity when primary fermentation in a vessel is "considered complete". ( Actually not quite complete but relatively stable)
PG, Present Gravity
The brewers technical term that should be used instead of FG and implies that beer which is then racked off might actually ferment further in it's final packaging either by nature or by the addition of sugars for secondary fermentation. PG is the term that HMRC use for beer duty.
PG is also the term for any intermediate reading if for example you chart the reduction in gravity during fermentation.
The generic term for all readings of gravity
OG, Original Gravity
The gravity of a wort after all processing ( liquoring up/liquoring down etc ) and prior to but ready for the introduction of yeast for fermentation.
FG, Final Gravity
An unofficial term, however it is commonly understood and used to indicate the gravity when primary fermentation in a vessel is "considered complete". ( Actually not quite complete but relatively stable)
PG, Present Gravity
The brewers technical term that should be used instead of FG and implies that beer which is then racked off might actually ferment further in it's final packaging either by nature or by the addition of sugars for secondary fermentation. PG is the term that HMRC use for beer duty.
PG is also the term for any intermediate reading if for example you chart the reduction in gravity during fermentation.