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Asked by tsahaiwork ·September 26, 2018 ·16.4k readers

FPJ (unripe fruit) overflowing

Hi, This is my second attempt to do FPJ from unripe baobab fruit (I'm a farmer in west africa). After 2 to 3 days, the buckets overflow with a foamy sludge. The taste is good, as well as the smell. But I don't know what to do to prevent it from overflowing. I tried adding sugar but it doesn't help much. So right now, I just divided the content of 1 bucket into 2. So what am I doing wrong? At harvest, the fruits fall on the ground so there is some soil attached to the skin of the fruit that I can't take out without washing it so I just left it there. I cut the fruit in small pieces, mix them in sugar (white sugar, I don't have access to brown sugar at a reasonable price right now) and put the mixture in white buckets (so I can see through a little bit). And I cap it with sugar. Buckets are more or less 2/3 full.  You can see liquid after a couple of hours (even though baobab fruit is quite hard and dry). But then, after 2 to 3 days it overflows. So if I collect the liquid after 24 hours, I don't think there will be any fermentation. When the fermentation starts, it doesn't seem to want to stop before everything is on the floor. Even when I remove the foamy part and put it separately in a bucket, it continues to "ferment". Thank you for your help (and for all the information available on the web) Tsaï

fpj-overflow-unripe-fruit

Top answer

Drake Weinert L4 Instructor · provisional Foundation · Sep 27, 2018
I also have this effect happen to me when I ferment ripe banana fruit. I make KNF Food according to the recipe, but the banana material traps in the gasses more than other materials, so it will rise above the 2/3 mark and many times overflow. To solve this problem, I place a metal screen over the material, then I place a few clean stones on top of that to weigh the material down so it will not rise when the gasses try to escape.  It sounds like after 3 days the material is probably pretty well fermented? I would imagine your climate is relatively warm as from my research west africa is even closer to the equator than Hawaii. If there is a slight alcohol smell, that is tell tale that the fermentation is complete.

From the KNF library

From the KNF library Drafted by Claude from Office Hours and the books · Sep 2026 · 3 sources

The library does not explain the foam, but it speaks to two things you asked about.

Drake recommends leaving the soil on. The recipe says not to wash the material and to use it with its own skin. (Cho, Recipe, p. 38)

Check your sugar by weight. Fruit takes close to equal weight in sugar, because it is juicier and sweeter than leafy material. (Office Hours Ep. 51, 34:01) Weigh the fruit and the sugar, then compare. (Office Hours Ep. 51, 34:01)

Unripe fruit is a sound material for this food. It is tied to the bloom stage. (Pure KNF Manual, p. 36)

The library does not say why a batch foams, how full to fill the bucket, or how to stop it once it starts.

Sources

1 more answer
tsahaiwork · Sep 28, 2018
OK, I'll try that thank you. And yes there is a slight alcohol smell after 3 days.  

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