January 28, 2018 at 11:16PM

Two days ago I learned: (I wrote up most of this on Friday and forgot to finish it out; instead of letting it die, I'm cheating and pushing it out today.) 1) ...a bit about the Impossible Burger, widely hailed as the most meat-like non-meat burger in the marketplace. My impression is that the Impossible Burger is a very, very heavily engineered food. A lot of effort went into making the texture, taste, and sound (yes, sound) of the Impossible Burger similar to that of a beef patty. However, if I were to collapse the Impossible Burger's design into one trick, that trick would be leghemoglobin. Leghemoglobin is a protein normally produced in the root nodules of soy plants, where it has something to do with oxygen buffering. The protein is structurally similar to animal hemoglobin and myoglobin, and acts similarly -- it complexes with a heme molecule, which allows it to efficiently bind dissolved oxygen. Heme, it turns out, is why bloody meats are red, and gives meat a lot of its rich, metallic flavor. Impossible Foods (the makers of the Impossible Burger) decided to make a burger with plant-based heme using leghemoglobin as a heme source. Unfortunately, soybeans don't make a lot of leghemoglobin, and it's a *pain* to extract, so Impossible Foods moved the gene for leghemoglobin (and, presumably, the enzymes required to make heme) into yeast, which is *very* easy to grow and relatively easy to extract proteins out of. That lets Impossible Foods make a rich, hemefull burger patty that's 0% animal. There's only one small catch, legally speaking -- leghemoglobin isn't FDA approved. It seems it doesn't *need* to be -- it's being sold anyway -- but just to be on the up-and-up, Impossible Foods sought FDA GRAS approval of leghemoglobin. They have some data feeding mass amounts of leghemoglobin to rats (no effects) and, perhaps more importantly, argued that leghemoglobin is an ancestral protein that we have no particular reason to think is toxic that's structurally very similar to tons of proteins we already eat all the time. The FDA rejected the approval request, I think on the basis that a) leghemoglobin might just be an allergen and b) there could be small amounts of other yeast proteins that make it through purification along with leghemoglobin that aren't necessarily human-safe (they're not using bakers' yeast, and I don't think the kind of yeast they are using is typically eaten in any appreciable quantity). 2) On a related note, Impossible Foods claims that 90% of the rennet used to make cheese is now yeast-produced. Whatdyaknow. This explains the multiple times I've run into "vegan cheese" that used rennet. I guess they were (probably) vegan after all. Those cheeses, when I've tried them, were significantly better than non-rennet vegan cheese, so I'm kind of excited to get back into the cheese substitute game. 3) If you want to burn little tea-light candles in water, don't take them out of their metal shells -- the wick of one of those candles is attached to a little metal pad, and when it heats sufficiently it will drill through the bottom of the candle and fall into the water, taking the rest of the wick with it. Bonus candle fact -- it's pretty easy to modify candles with tin foil by heating the tin foil over a lit flame and quickly pushing it into the candle somewhere.