Rwandan scientists develop local yeast for banana wine-makers
84 comments
·February 8, 2025bcatanzaro
johnofthesea
Optimal temperature for yeast in general is between 25-30C, for grape wine optimal fermentation is usually between 15-20C (white) 20-25C (red).
So 35C is interesting. 350 would be too much even if it was Kelvin.
throw-qqqqq
Kveik beer yeast often works well far above 35C. Some reportedly tolerate into low 40s.
I don’t know of other yeasts that can do this though.
giantg2
I was going to say, just throw some kiveik in it. That stuff is practically fool-proof
aDyslecticCrow
Yiest that could survive in volcanic geysers is a bit terrifying to think about.
tmoertel
It turns out that the Yellowstone Supervolcano is actually over-risen bread...
codesnik
free kombucha!
interludead
Still, the research itself is pretty exciting. It’s cool to see traditional methods getting scientific backing
piuantiderp
This made me snort my coffee, what backing was needed or lacking? Need peer-review to validate them?
nxobject
Consistency and reproducibility is important part of scientific backing, too.
jojobas
Especially given glucose decomposes under 200C.
nxobject
Mmm, caramel sweet wine, perhaps?
dluan
Bananas are notoriously hard to turn into a cleaner wine, mainly because of the fact that most bananas that are not Cavendish have a lot of latex and turn into goop. Most of the places where banana wine is produced (tropics) ultimately also turn it into banana "gin", and there's an incredibly deep and long cultural history of its production, e.g. it's tied to British colonialism in West Africa funded by liquor revenues, regulation was a hot topic of local protests, and drinking bars used to be hotbeds of nationalist agitation. When Nkrumah's CPP took over Ghana, they legalized homemade wine/liquor as a symbol against the gin drinking imperialists (in 1890 a bunch of countries in Brussels banned liquor importation to Africa).
The other much easier to produce wine and spirit comes from palm sugar (akpeteshie in Ghana, toddy in Indonesia), but the time window of when it is fresh and can be consumed is counted in hours, so it's not stable enough as an agricultural product to sell. Banana wine is an easy way to turn surplus calories into surplus cents.
gp
370 degrees Celsius? Hopefully a typo
Last time I was in Rwanda I had banana wine. It comes in beer bottles.
I think it’s an acquired taste - I didn’t have the acumen to acquire it myself.
lambda
The article mentions that it was provided by SciDev.net.
Looking there you find the original article, and it has the correction to the right temperature: https://www.scidev.net/global/supported-content/rwandan-scie...
culi
> The team looked for a fermenting agent that could remain reactive in substances with a temperature of up to 37 degrees Celsius* and alcohol of the recommended 16 per cent per volume.
> This article was edited on 29/01 to correct the temperature for fermenting to 37 degrees Celsius.
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ReptileMan
Fruit wines are tasty usually. But the hangover is on the next level.
b800h
This is because pectin in the fleshier fruits will be metabolised into methanol, which isn't very good for you.
Grapes are less of an issue.
werdnapk
All wine is made from fruit.
PaulHoule
Isn't "fruit" wine kind of a marketing term for "fruit flavored wine", that is "strawberry wine" is supposed to taste like a treat?
The one alcohol that I've made in large quantities [1] is apple cider [2] which I've always made very dry, even though I perceive it has an apple taste, pear cider tastes like pears, even if it is dry.
In sinosphere adaptations of classical Chinese stories like Romance of the Three Kingdoms people talk about drinking 'wine' but my understanding is that what they drank wasn't made from grapes.
[1] probably drank too much of it one December and might have started to get dependent
[2] on my farm we have a few hedgerows that have apples that are good for eating, seedling apples (in some areas surrounded by hedgerows) are usually yucky for eating, although horses think they are fine and they are great for cider.
gwd
The phrase I've heard is "country wine" -- e.g., any alcoholic beverage in the ABV of wine (10-18%) but not made exclusively from grapes.
InDubioProRubio
Not true, ever since we had advanced chemistry: https://en.wikipedia.org/wiki/Carbohydrate_synthesis
chongli
Nope. Rice wine, sorghum wine, barley wine. Those are 3 wines made from grains that I could name off the top of my head.
ReptileMan
Unlike classical grape wines, the fruit ones are quite "wet". And sweet alcohol for reasons unknown causes the worst of the hangovers.
samstave
[dead]
tiahura
Certain yeasts used in beer brewing produce an ester that is banana-like, especially when brewed at higher temps. It's often considered an off-flavor.
quijoteuniv
The article explains nothing, and has a very suspicious typo. If i heat something organic to 370 degrees i do want it to die :D
sjmulder
The explanation as to why flour yeast and grape wine yeast are unsuitable is a bit of a tautology. I know little about yeast. Can someone explain why one sort of yeast is not suitable for another use? And why is "sorghum, the traditional fermenting agent of banana wine" unsuitable or not acceptable to regulators?
stubish
Even more confusing: "We mixed the fermenting agent with sorghum flour to keep the traditional color and aroma of sorghum, the traditional fermenting agent of banana wine"
So they developed a yeast to replace the sorghum as the fermenting agent, and then mix sorghum in. What has been gained? Does yeast make for a more controlled fermentation making regulation easier? Or just easier to industrialize?
I suspect that using sorghum for fermentation really means using whatever wild yeast happened to be on the sorghum, and the results too variable to regulate for commercial sale or export.
dmurray
> I suspect that using sorghum for fermentation really means using whatever wild yeast happened to be on the sorghum, and the results too variable to regulate for commercial sale or export.
Definitely this. Sorghum is not a "fermenting agent": it's not an organism that eats sugars and shits out alcohol and carbon dioxide (actually, it's pretty much the opposite). It's just somewhere wild yeast likes to live.
dluan
It's similar to the malting process. Certain ingredients will contain enzymes and other important metabolites that can break down complex sugars into smaller simpler sugars that can be eaten by yeast (glucose, fructose). You need them to get a fermentation started and warmed up.
yial
Sorghum is acceptable I believe. It’s the fifth most produced crop in the world. It sounds like what might not have been acceptable is using wild yeasts to ferment it.
jrflowers
Different yeasts have different temperature and alcohol tolerance. For example a bread yeast may not continue making alcohol beyond 5-6%, or another yeast may only be productive in a narrow temperature range that’s too warm or too cool for a given application.
declan_roberts
They've been making banana wine from wild yeast presumably for at least a 100 years or longer. It sounds like the regulators in their country are a PITA and won't get out of the way.
There's a million different strains of yeast but they all do the same thing. If you don't add any yeast it will still ferment with the wild yeast.
dluan
Regulation is extremely important, and has been part and parcel of alcohol and wine production since prehistoric times. Besides the health reasons, wine is very easy to cut with synthetic or artificial ingredients, which has important economic and health consequences - hence the use of government bonding for hundreds of years around the world.
But more recently, regulation is vital for setting up geographical indicators for production of items that are locally unique, e.g. Parmesean, Champagne, and the German Reinheitsgebot which are legally protected practices for the reasons in the first paragraph. Being able to identify the specific strains of yeast in this banana wine is a big part for arguing the provenance of it.
stubish
You can't create an export market if you product is variable due to your results depending on whatever yeast happened to be used that day.
daurnimator
Lambic beers prove you can do that
collyw
I was thinking the same. Though wild fermenting works well for small batches, I have no idea of it scales. I was guessing this is a comercial operation if regulators are involved.
idunnoman1222
Normally, you ferment at lower temperatures because your drink will taste disgusting… (there will be terrible byproducts) this article has no explanation as to why this traditional drink suddenly tastes fine with a high temperature yeast other than something about regulators accepting some shit. I imagine that traditionally they they didn’t add commercial yeast… they just opened the top of it and prayed.. and the wild yeast which probably where they live Ferments fine at higher temperatures however, I had to make this all up in my head because there is no fucking information in this entire article and certainly no science and I’m amazed it’s number three. What the is this shit
jerrysievert
I think you need to try some kveik yeast, that might change your mind on high temperature fermentation: kveik is a Norwegian yeast, somewhat recently (last 25 years) rediscovered but brewed with for centuries, and can handle 37ºC without the byproducts.
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fmbb
Normally when you make banana wine?
DFHippie
Now I'm really curious to taste banana wine.
Banana is one of those flavors that some people love and some people really hate. Others in this category -- lutefisk, kimchi, certain cheeses -- make sense: their distinctive flavor is associated with decay. Why bananas, though?
My grandfather was a banana hater. His observation on the topic: "I hate bananas, and I'm glad that I hate them, because if I liked them I'd eat them, and I HATE them!"
vgrafe
I went a couple years ago in coutryside Rwanda, where locals brought me to a place where I could have some homemade banana wine, or "Urwagwa" (not sure about the spelling!). That place was someone's house with a few people hanging out and drinking, the wine was served in already-opened glass bottles.
For those curious, it is not very boozy (maybe around 7%-10% abv), but very yeasty - to a point where it kinda numbed my mouth. For those curious the yeast is the dominant flavor, followed by banana. Very earthy taste.
Later on I saw Urwagwa sold in a can at the airport, it was very different, no yeast but bitterness instead. I preferred the homemade one.
sram1337
Bananas are a staple food crop in some parts of Africa.
cmrdporcupine
It took me until my 30s to make the connection that bananas cause me intense headaches. I used to love to eat them, but now won't touch them.
I think I'm fine with them cooked, but not raw.
I don't know the mechanism, but if you do searches on bananas and headaches you will find people prescribing them as a cure for headaches, not the other way around.
btylke
It could be a latex allergy. Bananas are one of a few fruits that cause latex allergic reactions.
wileydragonfly
Kiwis. Avocado. Watermelon. Etc etc. the list is long.
interludead
I'm also curious about banana wine… wonder if it leans more toward fresh banana or that overripe, almost fermented taste.
dan353hehe
If I had to guess, it would be that fermenting bananas into wine makes them taste like they were fermented.
In all seriousness though, I can’t stand overripe bananas. Bleah.
skirge
what they want to achieve? Biofuels?
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interludead
Science helping tradition instead of replacing it
metalman
bannana wine, just does not work well in.english or bannana beer, or bannana cider, would be interesting to hear the term or terms used localy that might be evocative and perhaps marketable but certain words just dont work together..... like english, and cuisine, ha ha! it is and will forever be english food. rooooll your ooooo's
s0rce
Sorry, native english speaker here, what is wrong with banana wine?
metalman
nothing.....if you can make it work.....but in many native english markets, it wont, cept perhaps the kiddy booze market, where if you mix in enough tuarzine(whatever) and ??? purple blobs of some goo, it will jump off the shelves but as a meal acompanyment, no wait wait, with german desert wines going extinct there could be a market for a desert wine so......go for it, mang!
“The team looked for a fermenting agent that could remain reactive in substances with a temperature of up to 370 degrees Celsius and alcohol of the recommended 16 percent per volume.”
My guess is that the reporter forgot a decimal point and meant 37.0 degrees Celsius. Because finding a yeast that actively metabolizes sugar at 370 degrees Celsius might be somewhat challenging.