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03-22-2013, 04:30 PM   #1
hillbrewer
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 Calculating SG and ABV after adding stuff in secondary

I've done some searches about adding various things to beer in secondary, but I've yet to find an answer for this particular situation.

I just transferred 5 gallons of a pretty basic wheat ale (OG: 1.050 SG after primary: 1.011) to secondary yesterday and added the following:

2 lbs. sulfur-free dried apricots
3 cups Riesling at 11%abv and 2.23g/100ml residual sugar (SG 1.002 if that matters)

I combined all of that the day before and let it soak in the fridge. Before putting it in the bottom of my Better Bottle I brought it up to 160F and cooled it in the freezer to pasteurize.

I neglected to take a hydrometer reading immediately after racking the beer onto the fruit mixture, but this morning, despite some active fermentation that required a blow-off tube over night, my SG was 1.012, about the same as it was at the end of primary.

Have I missed my chance to calculate an accurate ABV? I certainly don't mind just having to guess, but it'd be nice to know just for the sake of the experiment.

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03-22-2013, 04:57 PM   #2
reverendj1
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Yes, you missed your chance to get an accurate ABV, but you can always guesstimate. Fruit is hard, because even if you did take a gravity reading, the fruit is solid, so there is no homogenous mixture in the beer. I plugged in 6 lbs of apricot puree (assuming you would lose 2/3 weight by drying them) and 8 oz of turbinato sugar into Beer Calculus and came up with 1.018, so it would add .018 points to your OG. We can extrapolate 3 cups of Riesling at 11%, diluted to 5 gallons (80 cups) would net you a .4% increase in ABV. 3/80*11 = .4125. So, I think if you raise your OG by .018, and calcuate ABV normally, then add .4 to that, you should have a decent estimate. So, by my calculations, I think you are right about 8% ABV.

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03-25-2013, 11:00 PM   #3
hillbrewer
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Thanks, those calculations definitely make sense. I'll settle for an estimate, and hopefully this experiment will turn out well.

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