Raspberries in Secondary

I plan on adding about 3 pounds of fresh raspberries to a cream ale that I currently have fermenting. My plan is to puree and pasteurize the raspberries and add them to the secondary.

I know the sugar in the raspberries will cause fermentation to kick off again. My question is how much more alcohol will that contribute to the beer?

My thought on measuring this is to take a hydrometer reading prior to racking to secondary and then taking a hydrometer reading after racking on top of the raspberries. The difference in the two should be the sugars added by the raspberries, so i'll take that difference and add it to the OG. Once fermentation is complete, the difference in my adjusted OG and the FG should be the number I use in calculating alcohol content (or letting beersmith do it for me).

One potential problem I see here is that not all the sugars from the raspberries will mix with the beer during the racking process, leading to a miscalculation of the added sugars.

Any thoughts on this?

you can drink six of them and see if you can still juggle three items of dissimilar weights. if you can't, it contributed a significant amount of alcohol. or you can't juggle, or you were already drunk to begin with. from 30,000 feet, this method is not very scientific, but then again, neither is the raspberry.

spearko520 said:

you can drink six of them and see if you can still juggle three items of dissimilar weights. if you can't, it contributed a significant amount of alcohol. or you can't juggle, or you were already drunk to begin with. from 30,000 feet, this method is not very scientific, but then again, neither is the raspberry.

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Everyone else go home....spearko has won the internets

No significant amount of alcohol will be added to the final product because you are also adding more liquid from the fruit as well as the sugar.

You also need to account for the liquid contributions from the fruit. It is mostly water weight.

bchurch said:

No significant amount of alcohol will be added to the final product because you are also adding more liquid from the fruit as well as the sugar.

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This is correct. There's a chart showing the brix of each fruit, but it's pretty much on par with normal wort gravity.

Thanks for the advice...and the humor. Hopefully this turns out to be a good experiment!

I wouldn't puree the raspberry I tried that one time and it made my raspberry stout very bitter. Now i just add the raspberies whole and I have not had that problem again.

My best results with raspberries has been to buy them frozen, let them thaw, freeze them again, and then thaw them before putting into secondary. Not only does the freezing kill off all the baddies on the raspberries, it denatures the cell walls and allows the fruit to contribute the most flavor/color to the beer.

I've always used frozen raspberries in my hefeweizen. Add three bags of frozen raspberries to a pint of water, heat to 170 to pasteurize, simmer for 20 minutes, cool them and rack on top of them. I found that to be the perfect flavor for my 5 gallon batch. I would also recommend leaving the raspberries whole rather than pureeing them, especially with three pounds.