Gravity of Sweet Potato?

[exhumedatbirth]

I'm brewing up a sweet potato stout this weekend, and plan on adding 5# of roasted, mashed sweet potato..does anyone have any guess as to how much this will effect my OG? I've tried a few recipe calculators, and searches but have come up with nothing..

 

[Misplaced_Canuck]

I'm brewing up a sweet potato stout this weekend, and plan on adding 5# of roasted, mashed sweet potato..does anyone have any guess as to how much this will effect my OG? I've tried a few recipe calculators, and searches but have come up with nothing..

Check out this post: https://www.homebrewtalk.com/f164/sweet-potato-mash-experiment-211386/#post3354406

You will need to cook the potatoes fully. In my case of using plain white potatoes, I cooked them in a water boil, and then mashed them and liquified them in mash water before adding to the main mash.

MC

 

[stillbrewin]

The sugar content in sweet potatoes is 4.2 grams for every 3.5 ounces of sweet potatoes. Sweet potatoes average about 22% starch and 5-6% sugar for a total of 27-28% fermentable material. So basically 5 lbs of sweet potato would be the same as adding 1lb of grain to your grain bill.

 

[Misplaced_Canuck]

The sugar content in sweet potatoes is 4.2 grams for every 3.5 ounces of sweet potatoes. Sweet potatoes average about 22% starch and 5-6% sugar for a total of 27-28% fermentable material. So basically 5 lbs of sweet potato would be the same as adding 1lb of grain to your grain bill.

5x22% would mean the same as may be one pound of 100% fermentable, aka, SUGAR, not grain. Lots of non-fermentables in grain.

MC

 

[stillbrewin]

5x22% would mean the same as may be one pound of 100% fermentable, aka, SUGAR, not grain. Lots of non-fermentables in grain.

MC

Hmm I may have been a bit hasty in my reply. 5 lbs should be about 96 grams of sugar or aprx 1/5th of a lb. Also the starch to sugar to conversion would equal about 2.2 lbs of grain. That is assuming that you get the same efficiency as your grain, and you figure 50% fermentable material in malted barly.