hydrometer question?

[rekamefink]

I boiled a Canadian ale yesterday and forgot to take a reading before pitching my yeast, the OG reading was supposed to be 1.054 but after pitching the yeast the reading was 1.060 I'm not worried, I'm just wondering how many points the yeast will change the reading?

Thanks

 

[mrbeachroach]

Not sure I'm giving the right answer here, but OG mesures the amount of sugar in the water. So adding yeast should not change the gravity reading at all unless you waited several days to take that reading after pitching. On that case the yeast wold have eaten some of the sugar and lowered your reading. As an example, I brewed a Russian imperial stout and at the end of fermentation o tossed in a pound of coffee beans and waited 2 weeks. It did not change the gravity reading at all. So the yeast would be the same way, having no sugar content it will not change your reading.

 

[WoodlandBrew]

Yes, a hydrometer measures the solution density. It will not be effected by particles in suspension like yeast. With a typical pitch of healthy yeast it only takes a few hours after inoculation for gravity to have dropped measurably.

 

[Ravenshead]

Most likely your initial reading was warmer than your second one. If your wort was warm, it will read a lower SG then it will after it cools a bit. Hydrometers are calibrated for 60* F so you need to take a temp reading and use a temperature correction calculator if you want an accurate measurement.

 

[rekamefink]

Thanks guys, the wort was about 70 degrees when I pitched the yeast.

 

[mrbeachroach]

Most likely your initial reading was warmer than your second one. If your wort was warm, it will read a lower SG then it will after it cools a bit. Hydrometers are calibrated for 60* F so you need to take a temp reading and use a temperature correction calculator if you want an accurate measurement.

Ravens head, I didn't know about the hydrometer calibration. Likely all my calculations are a bit off. What's the difference between the OG, of warmer wart and SG of warmer wart? Is that the same thing? I usually only deal with OG and FG.

 

[mrbeachroach]

.

 

[unionrdr]

SG just stands for Specific Gravity. OG/FG are Original (starting gravity) & final Gravity (ending gravity). Warmer wort gives a false higher measurement. Here's some gravity correction software; http://www.brewheads.com/gravcorrect.php

 

[Ravenshead]

What he ^^ said.