Calculating Alcohol With Fruit in Secondary

[Talgrath]

So I'm planning out my holiday/fall/winter brews, one of which will include cranberries and another that I'm thinking will use pumpkin. After looking through various posts and the like, I'm thinking I will add the fruit/gourd to the secondary, this would kick off a secondary fermentation though, my question is how exactly do you measure the alcohol of a brew where fruit was put in the secondary? If you go sheerly by the OG/FG you're going to be off by a lot, do you measure your pre-fruit FG, determine alcohol, then add the fruit and remeasure then look at the final final OG and add the two ABV results together?

 

[DesignatedDrinker]

your basically right but myself and most just use there OG and FG and not worry about the fruit additions.

This does not account for dilution which juicy fruits will give you. By adding all the fluids your are diluting your beer making it more difficult then its worth to get a TRUE calculation which is why most just use there original ABV. You will not be WAY off, just slightly. Adding 5lbs of diced mango to a pale ale only jumps the ABV a few 0.1's and thawed mango is one of the sweetest fruits ive tasted, but all that water addition dillutes the addition of ppg.

Hope this helps,
DD

 

[Talgrath]

It does quite a bit actually, I haven't been able to find anything on this, you would think fruit would bump up ABV by more than that, but fair enough.

 

[DesignatedDrinker]

Ya it would bump it up a ton if you werent adding all the water that comes with it. You have to think, most juicy fruits are 1/2-3/4 water.

 

[pdxal]

General consensus lately has been that the sugar in the fruit/vegetable will increase the ABV, but the volume of water in it will dilute it, leaving it roughly the same as before adding.

http://www.themadfermentationist.com/2010/10/adding-fruit-to-beer-increases-alcohol.html

 

[Calder]

Ignore it, and work off the base beer OG/FG calculation.

In most cases, fruit addition will actually lower your effective OG (which no-one wants to hear), so ignorance is probably the best way to go.