← All questions

Asked by danpthomas ·November 2, 2018 ·6.73k readers

FFJ. What’s next

Hey. I made some pear and apple FFJ. On day 7 I extracted the juice. It’s still foaming. Just wondering how much brown sugar I should add. Thanks

ffj

Top answer

Drake Weinert Foundation · Nov 10, 2018
Enough to supersaturate it, which means every water molecule is bound with a sugar molecule. If this was pure water, it would be equal volume, but since there is a variable quantity of sugar already in your knfFood, you will have to slowly add sugar while stirring to detect the signs of supersaturation, which include the sugar starting to float on the top of the surface of the liquid.

From the KNF library

From the KNF library Drafted by Claude from Office Hours and the books · Sep 2026 · 2 sources

Drake recommends no fixed amount of sugar for this juice. The sugar content of a poured-off solution varies, so the amount varies too. (Pure KNF Manual, p. 80)

For a safe upper bound, add brown sugar equal in volume to the juice. To avoid wasting sugar, add it slowly and stir thoroughly. (Pure KNF Manual, p. 80)

Watch for the sugar to start floating on the surface like an iceberg. That tells you supersaturation is near. (Pure KNF Manual, p. 80)

Past that point the microbes hibernate. They can't get water without getting sugar, and the sugar dries them out. (Pure KNF Manual, p. 80)

For storage, the KNF Demystified steps say to keep the poured-off liquid in a breathable container. Store it out of direct sunlight, where the temperature stays steady. (KNF Demystified, p. 37)

The library does not say whether foaming at day 7 is normal or what it means.

Sources

  • p. 37 KNF Demystified · “Pour off and retain liquids in a breathable container and store out of direct sunlight where there will be little temperature fluctuation”
  • p. 80 Pure KNF Manual · “Supersaturating PureFood is a different story as the sugar content of the poured off solution will vary.”

Also discussed on Office Hours

Ep. 144· Sep 29, 2024 ·15 questions answered

JADAM Sulfur Pesticide, Water Softening, Wetting Agent Test

jadam sulfur soap water softener wetting agent test mixture test

Know the answer? Members answer, ask, and get their questions onto the Sunday show.

Sign in Become a member