Homebrewers - Whats in the fermenter?

[St. Lou Stu]

Originally Posted by earnold25

Started my first batch last week. An Irish stout. Fermentation has slowed considerably. Wondering when to start taking gravity readings. (tapping my foot impatiently)

I usually wait 3 weeks before taking gravity readings now.
In my impatient times, I started measuring after 10 days.

[earnold25]

Originally Posted by St. Lou Stu

I usually wait 3 weeks before taking gravity readings now.
In my impatient times, I started measuring after 10 days.

Cool. One other thing in my OG was higher then the recipe stated it should be. (I'm guessing not enough water?). Do I need to adjust the FG to know when I'm done or use what the recipe states for that?

[St. Lou Stu]

Originally Posted by earnold25

Cool. One other thing in my OG was higher then the recipe stated it should be. (I'm guessing not enough water?). Do I need to adjust the FG to know when I'm done or use what the recipe states for that?

What was your starting gravity?
What yeast did you use?
What temperature have you been fermenting at?
Was this an extract batch? Did it have steeping grains?

Answer those and I can give you a target range for Final Gravity... and the method for figuring it out.

[earnold25]

What was your starting gravity? 1.065 ( recipe said 1.046 - 1.050)
What yeast did you use? Wyeast Irish ale prop. ( on a starter)
What temperature have you been fermenting at? Around 68 - 70
Was this an extract batch? Did it have steeping grains? Yes and yes ( steeped at 150)

Answer those and I can give you a target range for Final Gravity... and the method for figuring it out.

Thanks!

[St. Lou Stu]

Originally Posted by earnold25

What was your starting gravity? 1.065 ( recipe said 1.046 - 1.050)
What yeast did you use? Wyeast Irish ale prop. ( on a starter)
What temperature have you been fermenting at? Around 68 - 70
Was this an extract batch? Did it have steeping grains? Yes and yes ( steeped at 150)

Answer those and I can give you a target range for Final Gravity... and the method for figuring it out.

Thanks!

mkay, Wyeast 1084 will have 71-75% attenuation and all of your conditions look great for that yeast so you could expect a 1.019-1.016 final. I would lean towards the higher side of middle since it is extract with steeped grains. If you hadn't done a starter, I would say the high end.

Here's how I came up with that:
FG = -(((A%/100)(SG-1))-SG)

Note the negative symbol in front of the parens. it'll work without, but yield a negative number.

FG is the final gravity for a given starting gravity (SG) and a given attenuation (A%).
Yeast strain attenuations can be found on their respective manufacturer sites. I always plug in the high (75% in this case) and low (71%) to get the min/max and make judgments based off of conditions.

What did the recipe say final would be? 1.012-1.015?

[earnold25]

Originally Posted by St. Lou Stu

What did the recipe say final would be? 1.012-1.015?

close. 1.011-1.014

thanks for the help. i'll keep ya posted

was i correct in assuming that the OG was off due to not enough water in the final wort? i.e. too much boiled off?

[St. Lou Stu]

Originally Posted by earnold25

close. 1.011-1.014

thanks for the help. i'll keep ya posted

was i correct in assuming that the OG was off due to not enough water in the final wort? i.e. too much boiled off?

Funny, I rounded up and they truncated. My actual calcs were 1.0115 and 1.0145.

That is the most likely thing that coulda done it. Although, you woulda had to have lost quite a bit due to boil off to get that high. Cold break and trub in the sample can also give false high gravity readings. I always manage to screw up temperature factors on warm readings too (calculation error?).
If you run short again you can always add plain, boiled water to the wort to top off prior to fermentation and after the boil.
Regardless, it'll be fine.