Im Brewing a Pineapple IPA style beer, and will be adding Pineapple juice for flavoring after the boil for the first try, and trying to understand what the added sugar content will be if adding a 5% volume addition. If Pineapple juice has 110 grams of natural occurring sugars per liter… how do we calculate the PSG of the juice to get our estimated OG? any thoughts… cheers JJ
I just calculate the weight of sugar being added, then plug that in as if it was table sugar. And the calcs are easier if you convert everything to metric first.
Assuming a 19 liter (5 gallon) starting point for the beer, that will mean ~1 liter pineapple juice with 110 g of sugar added. 110 g = 4 oz, which according to ProMash is enough to raise the OG by 2 pts.
Some other things you may want to consider: Add the pineapple juice after you cool the wort to prevent getting a “cooked” flavor from it, and to prevent the pectin from setting and causing a haze in the beer. And you may want to add some pectic enzymes to further ensure no problems from the pectin.
I would take a sample of the pineapple juice and get a gravity reading on it with a hydrometer, simple as that. Once you know that, you can plug that value into your OG calculations. I think you could safely assume that most of the value you see above 1.00 is fermentable, at least 80%. I wouldn’t worry too much about getting an exact value. I’m curious about exactly where you got the idea for this beer, though. Did you find a recipe for this somewhere, or is this your own idea? I’d love to hear how it turns out.
Actually, it is simpler than that. Fruit juice is mostly fructose and gluctose, with perhaps some sucrose and minor additions of other sugars. The important point is that there is basically no maltrose or other “hard” for yeast to ferment sugars in it. Thus, it ferments out almost 100% and you can consider all the sugar in the juice to be simple table sugar.
Thanks for your responses. I knew more or less the added value of the juice/s but was hoping to have some kind of formula for specific juices. I think its safe to use it as just a sugar addition on the brewing program to get a good idea of the psg Being to anal about it maybe ? The Pineapple flavor really is nice in the IPA… at least I think so… Not my idea, first tried it from spearhead brewers in Toronto Can :cheers:
