The Origins of Agar
59 points by surprisetalk 5 days ago | 15 comments

zabzonk 10 hours ago
Way back when, I used to work in microbiology. One of our favourite tricks when we were bored was to fill a rubber glove with molten agar and dye. When it set, we cut off the glove and left it where some unsuspecting person would come across it.

We were often a bit horrible given to practical jokes back then (1970s), but I also remember exploring an unused store room (fighting off giant cockroaches) and coming across a litre (or two?) of pure 100% Analar ethanol, which made for a merry lab-rat party (not drunk straight from the bottle) for all.

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kqr 15 hours ago
I don't know anything about laboratory uses of agar, but I do use it in cooking. Something that baffles me is that so many recipes (at least in northern Europe) use gelatin when agar works just as well or better. Agar is cheaper, easier to handle, comes in more compact packaging, lasts longer, sets faster, is reversible, fits more food preferences, etc. Why this obsession with gelatin? What am I missing?

The article contains one possible clue: gelatin melts at body temperature. This implies dishes made with gelatin melt in the mouth like chocolate does, but I can't recall experiencing that (at least not to the extent of chocolate) when eating gelatin-based stuff. (And many gels, at least in my opinion, have a better mouthfeel when more solid than liquid.)

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evgen 13 hours ago
Gelatine melts at a lower temperature and has a much better mouthfeel for most of these traditional recipes. It is creamy and adds body to a stock or sauce. Agar is brittle and requires a higher temperature to set. Agar would be a good choice for something where you want it to stay in a particular shape, but it is much more of a one-trick pony when it comes to cooking. Each can act as a poor man's version of the other, but neither really hits the same features as the other.

Agar is great for a gel, especially one you want to stand up to a bit of heat and remain stable at room temp, and I would always reach for it instead of gelatine when doing most desserts or pastry work. OTOH I would only use it in a sauce if I needed to accommodate a vegan guest.

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duozerk 11 hours ago
> I would only use it in a sauce if I needed to accommodate a vegan guest.

As an alternative, I've found methylcellulose to be pretty good for thickening my vegan homemade sauces (mainly tried it because I use it for other stuff, like fakemeat homemade protein sources). That's for homemade mayo or the like; for sauces in stews and similar, flour does the job - though US cooks seem obsessed by cornstarch instead for that use case.

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Tagbert 7 hours ago
They are ‘obsessed’ with cornstarch instead of flour because cornstarch is almost pure starch and doesn’t add a flavor the way that flour does. It shares that property with methylcellulose.
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duozerk 6 hours ago
Thank you ! I imagined it was a cultural thing, good to know.
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gucci-on-fleek 14 hours ago
> Why this obsession with gelatin? What am I missing?

Probably just tradition. It's pretty easy to "accidentally" make gelatin when making a broth, and intentionally making it only requires heat and bones, which are essentially pure waste. Whereas agar is a product that you have to buy in a store, and wasn't even available in the West until somewhat recently.

Of course, everybody just buys gelatin in the stores these days, and agar is almost as easy to find, but old recipes tend to be handed down for generations.

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JKCalhoun 8 hours ago
I was unaware (until I read the article) that it was used in cooking.

There is a family story that I had been fed a good deal of agar as a baby since my parents were poor but my father was at a state university and the agar was able to walk out the door with him from lab classes (and I think he worked as a lab assistant/technician to pay for school).

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nkrisc 11 hours ago
If you’ve had soups and broth made with lots of bones, and you want to recreate that same mouth feel and experience without using loads of bones, then you can achieve that by using gelatin, because gelatin is exactly what the first dish had that yours is missing. It’s literally the missing ingredient if you’re not cooking with the bones.

Also, they simply aren’t perfect replacements for each other. Agar and gelatin are certainly similar in many ways, but the are not the same.

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wolfi1 6 hours ago
since mad cow disease times one would believe they search for alternatives in their recipes but this seems not to be the case
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zabzonk 10 hours ago
> can't recall experiencing that (at least not to the extent of chocolate) when eating gelatin-based stuff.

The traditional jelly around the outside meat of British pork pie would frankly be weird texture (and probably horrible) if it was made from agar. It really has got to be made from pork bones to be authentic. It does melt in the mouth, when the pie is properly made - sadly rare these days.

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andrewflnr 4 hours ago
Stupid question: is the "nutrient broth" mixed with the agar, then poured into the dish? The overall procedure is a little unclear to me, and the article seemed to take it for granted. I'd always been under the impression that the agar itself was food for the microbes, which is... silly in retrospect.
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virgulino 7 hours ago
Unrelated but in name:

Agar-Agar, the Parisian artsy synth-pop duo - "How do we find out if we already live in a simulation?"

https://youtu.be/7Qp44a0uaeU

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smusamashah 12 hours ago
Didn't know that agar.io was based on a real thing. That name always felt weird.
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mrbluecoat 14 hours ago
> thrives only in cold, turbulent waters over rocky seabeds, conditions nearly impossible to replicate in aquaculture

With our warming climate, I wonder if research is happening to develop heat-resistant agar, similar to coffee, cocoa, and rice.

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datawars 9 hours ago
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