Should I top-off?

[bacchusmj]

Just overhauled my equipment (blichmann burner and Megapot) and did my first batch. Mini Burton ale. anticipated OG was 1.055 but I got pretty great efficiency and hit about 1.062. However, because the boiloff was more than expected (60 minute boil) I was left with only 4.3 gallons in the fermentor.

So, should I top off to get back to around 5.25 g? How will that end up affecting my OG? I had to take a family break so the wort is just chilling in my garage waiting to get pitched.

 

[Yooper]

Just overhauled my equipment (blichmann burner and Megapot) and did my first batch. Mini Burton ale. anticipated OG was 1.055 but I got pretty great efficiency and hit about 1.062. However, because the boiloff was more than expected (60 minute boil) I was left with only 4.3 gallons in the fermentor.

So, should I top off to get back to around 5.25 g? How will that end up affecting my OG? I had to take a family break so the wort is just chilling in my garage waiting to get pitched.

Top up to get to 1.055 if that is your target. That will keep your balance and recipe correct, regardless of volume.

 

[bacchusmj]

thanks yoop. Ill just start with 3 quarts and go from there.

 

[Hex23]

thanks yoop. Ill just start with 3 quarts and go from there.

Not to split hairs, but you'll need a little closer to 1/2 gallon to get 1.055.

It seems like the reason your gravity was higher could have more to do with boiling off more than planned, not better efficiency than expected. Your efficiency may be close to what you expected or a little less.

 

[woozy]

Also not to split hairs, and not to be a dampy downer, but your effecienty isn't based on o.g. It's based on specific gravity _times_ volume size. And it doesn't matter when you measure. You can measure (and you should) *before* the boil when your specific gravity will be low but your pre-boil volume is high.

An expected post-boil o.g. of 1.055 at 5 gallons is 55 gravity points times 5 gallons or 275 gallon-points. You got 1.062 but at 4.3 gallons for 62 times 4.3 gallons 266.6 gallon-points.

So your efficiency was *slightly* _less_ than anticipated.

If you top off to 5 gallons your O.G. will be 1.053 (266.6 gallon-points/5 gallons = 53.32 points). Which is pretty good. Good enough.

[To get *exactly* 1.055 you'd top off to 4.85 gallons (266.6 gallon-points/55 points = 4.847273 gallons) but that *really* is splitting hairs.]

 

[Hex23]

While we're splitting hairs ... Similar calculations are what I used to make my comments, but I took the intended volume into the fermenter to be 5.25 gallons. So maybe a little less than slightly less efficiency vs. anticipated

 

[woozy]

While we're splitting hairs ... Similar calculations are what I used to make my comments, but I took the intended volume into the fermenter to be 5.25 gallons. So maybe a little less than slightly less efficiency vs. anticipated

Actually, yeah. That occurred to me latter but I figured I had been enough of a damper already.

Expected efficiency corresponds to 55 points * 5.25 gallons = 288.75
Achieved efficiency corresponds to 62 points * 4.3 gallons = 266.6
Thus efficiency wasn't met but it's fair to call it "slightly less" (it was 92 percent of the way there; I've done worse. I *usually* do worse. I've only once gotten better than anticipated efficiency.)

Meanwhile topping off to 5.25 yields 266.6/5.25 = 51 points or 1.051.

But I'm with yooper. Top to correct volume for balance and correctness rather than to gravity points. And being off by four gravity points is trivial.

But damper downer me still needs to point out that the OP did not get "pretty great" efficiency; quite the opposite really.