Whole Fruit PPG Data

[bobbrewster]

Cheers!!!

I just made a pineapple IPA for a friend and I didn't take gravity readings before and after pitching 4 lbs (2 whole pineapples), like I should have. I cut them up and puree'd them into my 2ndary.

Question: Does anyone know where to find PPG data for using whole fruit? I've seen a lot for using concentrates but not whole fruit.

Thanks!

 

[VikeMan]

Well, you can't take a meaningful gravity reading after adding fruit. The water and the soluble carbs in the fruit don't homogenize with the wort/beer immediately. But there's an excel calculator that can be downloaded from this page that you might find helpful:
http://sonsofalchemy.org/library/

 

[bobbrewster]

Vike, thanks!. Great calculator.

Now you've got me curious. So, my pureed and pasteurized pineapple, thoroughly stirred into the primary, isn't homogenized"? I figured after primary fermentation I could just take my final gravity reading (1.004 in this case), thoroughly mix in the 1/2 gallon puree, then take another reading (new OG), let it ferment for another week or two, then take another (new FG) reading, giving me my PPG for the pineapple. I mean I REALLY pureed this pineapple, almost to a liquid state. I'm sure the OG I'd get from it would be >95% homogenized, it seems. Do you, or anyone else, have some good references on homogenization, as it applies to brewing, specifically with whole fruit?

Thanks again!

Well, you can't take a meaningful gravity reading after adding fruit. The water and the soluble carbs in the fruit don't homogenize with the wort/beer immediately. But there's an excel calculator that can be downloaded from this page that you might find helpful:
http://sonsofalchemy.org/library/

 

[VikeMan]

Now you've got me curious. So, my pureed and pasteurized pineapple, thoroughly stirred into the primary, isn't homogenized"?

Well, if you literally juiced it, then yes, it would mix completely and "immediately." But if there were any cells not yet broken down, then no.

I figured after primary fermentation I could just take my final gravity reading (1.004 in this case), thoroughly mix in the 1/2 gallon puree, then take another reading (new OG), let it ferment for another week or two, then take another (new FG) reading, giving me my PPG for the pineapple.

You could make some inferences from this. You'd have to be careful about volumes in your calculations. The fruit adds volume, and only some of it is relevant.

Do you, or anyone else, have some good references on homogenization, as it applies to brewing, specifically with whole fruit?

I don't know of anyone who has collected data on this. But I'm pretty confident in saying that the longer the fruit is in contact with the beer, the more homogeneous it becomes. And the time needed will be different depending on the fruit and how it was prepped.