Blasting Yeast with UV Light • Hacker News Board

Re: Blasting Yeast with UV Light

#21

Post by dzink » Thu, Nov 13, 2025, 5:01 AM UTC

teruakohatu wrote: post #18

crdrost wrote: post #13

Earlier quoted context omitted.

There are a bunch of tricks like this. So for instance to make antibiotic-free chicken without a commitment to being antibiotic-free and organic, raise a bunch of chickens, take any who gets sick enough to need antibiotics and put them into a separate field with their antibiotics, sell the ones that happen to not get sick as antibiotic-free, sell the other ones as usual. Or, if you're making orange juice, make the in…

In New Zealand our cow’s milk is separated into its components and then reconstituted and bottled. I would think it’s the same elsewhere too.

I grew up with real cow milk from neighborhood cows and I can taste the difference. To this day I won’t buy milk that tastes reconstituted.

Re: Blasting Yeast with UV Light

#22

Post by tdeck » Thu, Nov 13, 2025, 5:27 AM UTC

teekert wrote: post #4

Fun story. I worked at a large food tech company. For products like Yoghurt you’d like Bactria that make the yogurt very quickly at high temp. But grow as slowly as possible at low temp (stays fresh longer). They’d mutate the s out of these Bacteria, in smart calculated ways. A basepair here, a gene there. When they hit a jack pot. They’d document the mutations, throw the engineered strain out and start blasting them…

This reminds me of atomic gardening, where you just blast plants with gamma rays and see if you get something useful

https://en.wikipedia.org/wiki/Atomic_gardening

They still do it in Japan, with a distinctive circular field that has a radioactive isotope tower in the center

https://www.naro.affrc.go.jp/archive/nias/eng/org/GR/IRB/

Re: Blasting Yeast with UV Light

#23

Post by teekert » Thu, Nov 13, 2025, 6:19 AM UTC

secondcoming wrote: post #8

teekert wrote: post #4

Fun story. I worked at a large food tech company. For products like Yoghurt you’d like Bactria that make the yogurt very quickly at high temp. But grow as slowly as possible at low temp (stays fresh longer). They’d mutate the s out of these Bacteria, in smart calculated ways. A basepair here, a gene there. When they hit a jack pot. They’d document the mutations, throw the engineered strain out and start blasting them…

How can you scan millions of things looking for one or two that have a mutation?

Back in the day there were pipetting robots and 384 well plates. Probably some smart grouping techniques to hone in on a mutation in a binary search like fashion.

But nowadays we have things like single cell sequencing, which allows you to label thousands of cells with unique DNA barcodes (not the cell itself but the sequencing library you construct to go into the sequencer), and sequence them all in a massive parallel fashion.

Basically all of molecular (and other types) biology is now "high throughput", consequently data science has become very important for biologists.

Re: Blasting Yeast with UV Light

#24

Post by rcxdude » Thu, Nov 13, 2025, 10:00 AM UTC

secondcoming wrote: post #8

teekert wrote: post #4

Fun story. I worked at a large food tech company. For products like Yoghurt you’d like Bactria that make the yogurt very quickly at high temp. But grow as slowly as possible at low temp (stays fresh longer). They’d mutate the s out of these Bacteria, in smart calculated ways. A basepair here, a gene there. When they hit a jack pot. They’d document the mutations, throw the engineered strain out and start blasting them…

How can you scan millions of things looking for one or two that have a mutation?

PCR allows you to detect a particular DNA sequence at extremely low concentrations (essentially, by duplicating any DNA that matches it many times).

Re: Blasting Yeast with UV Light

#25

Post by seanwilson » Thu, Nov 13, 2025, 11:19 AM UTC

For sourdough and breadmaking, I always find it funny how recipes and tips make out like yeast is almost delicate and hard to keep happy when we know yeast is super tough. It can survive drying, cold/freezing, high pressure, having no food for a long time, up to 50C heat, and more.

It's also easy and cheap to run experiments too like mixing salt directly with the yeast and seeing it doesn't make a noticeable difference to breadmaking, yet the myths persist.

Re: Blasting Yeast with UV Light

#26

Post by mtrovo » Thu, Nov 13, 2025, 2:22 PM UTC

seanwilson wrote: post #25

For sourdough and breadmaking, I always find it funny how recipes and tips make out like yeast is almost delicate and hard to keep happy when we know yeast is super tough. It can survive drying, cold/freezing, high pressure, having no food for a long time, up to 50C heat, and more. It's also easy and cheap to run experiments too like mixing salt directly with the yeast and seeing it doesn't make a noticeable differen…

The problem in general is consistency. Bread is very forgiving on flavour profiles so what you're saying works fine within a good threshold. For breweries it's usually not worth it as there are lots of nuances on the mutations of the harvested yeast and their effects into the flavour profile of the final product. There are some exceptions like natural fermented beers or anything related to kveik yeast, but in general people don't reuse yeast past 1-2 brews.

Re: Blasting Yeast with UV Light

#27

Post by TomMasz » Thu, Nov 13, 2025, 2:22 PM UTC

A local apple farm and cider mill uses UV for pasteurization of their cider instead of heat. I use it to make hard cider, and it's as good as unpasteurized cider (no longer legal to sell in NY) was, and I don't have to use sulfites to kill off wild yeast.

Re: Blasting Yeast with UV Light

#28

Post by kaikai » Thu, Nov 13, 2025, 8:10 PM UTC

lmm wrote: post #15

crdrost wrote: post #13

Earlier quoted context omitted.

There are a bunch of tricks like this. So for instance to make antibiotic-free chicken without a commitment to being antibiotic-free and organic, raise a bunch of chickens, take any who gets sick enough to need antibiotics and put them into a separate field with their antibiotics, sell the ones that happen to not get sick as antibiotic-free, sell the other ones as usual. Or, if you're making orange juice, make the in…

> So for instance to make antibiotic-free chicken without a commitment to being antibiotic-free and organic, raise a bunch of chickens, take any who gets sick enough to need antibiotics and put them into a separate field with their antibiotics, sell the ones that happen to not get sick as antibiotic-free, sell the other ones as usual. I think I'm ok with this. It means you can't routinely feed them all antibiotics, a…

People are still eating them, they’re just people who weren’t willing to pay extra for non-antibiotic chickens.

There’s a withdrawal period for livestock medication for all slaughter, so no one should be eating animals that were recently medicated. IIRC it’s 30 days for LA200, the antibiotic I used for my flock.