Estimate SG of fruit

[Newsman]

Hey, folks... I'm a bit unsure how to calculate the SG of fruit. I know there are some conversions for that, but I've been unable to locate anything. I know the carb content of the fruit, but I'm not sure how to turn that into SG to add to my OG.
Any help would be appreciated.
X-posted from Mead Brewing forum

 

[lumpher]

Hey, folks... I'm a bit unsure how to calculate the SG of fruit. I know there are some conversions for that, but I've been unable to locate anything. I know the carb content of the fruit, but I'm not sure how to turn that into SG to add to my OG.
Any help would be appreciated.
X-posted from Mead Brewing forum

I just use the rule of thumb that the water in fruit will counter the sugar it has. If you want to check using a recipe builder, Brewer's Friend has fruit in the Fermentables section.

https://www.brewersfriend.com/homebrew/recipe/calculator

 

[Newsman]

I just use the rule of thumb that the water in fruit will counter the sugar it has. If you want to check using a recipe builder, Brewer's Friend has fruit in the Fermentables section.

https://www.brewersfriend.com/homebrew/recipe/calculator

Can you advise where to find that?I don't see any option for fruit

Edit: found it. It gives me the same OG as I got from my hydrometer, but it isn't taking into account the sugars in the fruit???

 

[mac_1103]

It gives me the same OG as I got from my hydrometer, but it isn't taking into account the sugars in the fruit???

Not sure what you're trying to say here. Can you please clarify what you measured the gravity of and why you think Brewer's Friend isn't accounting for the fruit if you got measured the same gravity it predicted.

I'm playing around with Brewer's Friend right now adding random amounts of random fruits. Every time I add something the OG increases.

 

[Newsman]

I measured the OG using a hydrometer. It came in at approximately 1.110. Brewer's Friend said the OG should be exactly that.

 

[Newsman]

Also, I added fruit with a total of 83 sugars/carbohydrates.

 

[mac_1103]

I measured the OG using a hydrometer. It came in at approximately 1.110. Brewer's Friend said the OG should be exactly that.

OK then. It sounds like Brewer's Friend is calculating the OG of your fruit additions correctly. So what exactly is the problem?

 

[Newsman]

OK then. It sounds like Brewer's Friend is calculating the OG of your fruit additions correctly. So what exactly is the problem?

I don't think it is, because the OG shouldn't include the sugars locked in the fruit, IMHO

 

[mac_1103]

OG shouldn't include the sugars locked in the fruit, IMHO

Alright, that's the opposite of what I thought you were saying. So why shouldn't it include the fruit sugars? They end up in the wort (as your hydrometer reading shows) and they're going to get fermented.

 

[Newsman]

Alright, that's the opposite of what I thought you were saying. So why shouldn't it include the fruit sugars? They end up in the wort (as your hydrometer reading shows) and they're going to get fermented.

Because they aren't available yet. The yeast has to break down the fruit and extract the sugars in the fruit.
Edit: I'm saying I think the OG should be higher than measured as I have 83 more grams of sugars that the hydrometer shouldn't be able to measure.

 

[mac_1103]

Because they aren't available yet.

If your hydrometer is measuring them then they are available. How did you add the fruit? Unless it's whole fruit added after you chilled the wort, then the sugars are going to be (at least partly) available. If you want to exclude the fruit contribution to OG, check the "late addition" box and select "fermenter."

 

[Newsman]

If your hydrometer is measuring them then they are available. How did you add the fruit? Unless it's whole fruit added after you chilled the wort, then the sugars are going to be (at least partly) available. If you want to exclude the fruit contribution to OG, check the "late addition" box and select "fermenter."

Whole fruit added to my apple juice and honey mix.

 

[hotbeer]

What was the SG of your apple juice and honey mix prior to adding the whole fruit?

You'd be just as well off guessing what the amount of sugars in your fruit is. Any charts, tables or listing of the amount of sugar is going to be wildly variable. Your fruit might not be the same ripeness as the fruit that was tested.

Keep good notes and you'll know what to expect with future batches. If you want to make a good guesstimate, then puree one of your fruits and mix it with a known quantity of water, measure the SG and calculate what it is. Refractometers are somewhat ideal for determining Brix of fruit.

 

[mac_1103]

Whole fruit added to my apple juice and honey mix.

When? If the measured OG matched the predicted OG with the fruit included, then either something extracted the sugars from the fruit really quickly or (more likely) Brewer's Friend underestimated the PPG of your apple juice and honey and the matching gravities are just a coincidence.

 

[Newsman]

When? If the measured OG matched the predicted OG with the fruit included, then either something extracted the sugars from the fruit really quickly or (more likely) Brewer's Friend underestimated the PPG of your apple juice and honey and the matching gravities are just a coincidence.

Keep in mind. There was no heat. Plain apple juice and honey. OG before fruit was 1.110

 

[mac_1103]

OG before fruit was 1.110

OK, I thought you said that was with the fruit. What kind of fruit? Fresh or frozen? Now I'm wondering how much of the sugar is ever going to be available to ferment.

 

[Newsman]

OK, I thought you said that was with the fruit. What kind of fruit? Fresh or frozen? Now I'm wondering how much of the sugar is ever going to be available to ferment.

Frozen/thawed. 1# sliced peaches and 10 Oz Mangoes