Finding OG after adding fruit to secondary

[leskohomebrews]

I want to add raspberries to a wheat ale. If I add them to the secondary fermentation, do I need to find a new OG? Do I just mix the berries in and take a sample? Do I need to do anything with the OG from the original wort in primary?

 

[Sammy86]

I want to add raspberries to a wheat ale. If I add them to the secondary fermentation, do I need to find a new OG? Do I just mix the berries in and take a sample? Do I need to do anything with the OG from the original wort in primary?

No need to find a new OG...make sure you take note of the gravity at the time that way when you take another reading you have an idea of how much further the gravity dropped.

 

[leskohomebrews]

No need to find a new OG...make sure you take note of the gravity at the time that way when you take another reading you have an idea of how much further the gravity dropped.

So say I started at 1.045, and then added raspberries. Would I measure the gravity before or after adding the berries, and once I take that reading, how do I use them to determine alcohol once I have a final gravity?

 

[Sammy86]

So say I started at 1.045, and then added raspberries. Would I measure the gravity before or after adding the berries, and once I take that reading, how do I use them to determine alcohol once I have a final gravity?

If you add the raspberries during primary fermentation I would be extremely careful to reduce oxygen and I would also be cautious about infecting it as well.

If you wait until secondary, you take the gravity reading, add the berries and wait your allotted time for secondary fermentation. Once the time is complete you take a reading and then use an ABV calculator by putting in your OG and FG.

There is a math formula I just don't know it nor care to do it by hand because you know, Math is hard...LoL

 

[rburrelli]

You are over thinking it. Original gravity and final gravity are just starting and ending points in the process. Anything else in between does not change things.

 

[Konstantianus]

To find the SG you'll need to have accurate measurements of the SG of the wort, volume of the wort/beer, SG of the fruit (Raspberries in this case) and volume of the raspberries. This is assuming that your fruit is all liquid otherwise your calculations will be off.

You'll need to calculate the gravity points of both the wort/beer and fruit.

SG in whole points x volume will give you the total gravity points. From there add the gravity points of both and the volumes of both and divide the resulting SG by the volume.

Example:
Lets say you have 5.7 Gallons of wort at an SG of 1.045 and 16 Ounces (Fluid) of Raspberries at and SG of 1.012

45 x 5.7 = 256.5 Wort Gravity Points
12 x 0.125 = 1.5 Raspberry Gravity Points
(1 Gallon = 128 Fl. Oz. - 16/128 = 0.125)

256.5 + 1.5 = 258 Total Gravity Points
5.7 + 0.125 = 5.825 Total Volume

258 / 5.825 = 44.29
1.04429 is your adjusted OG