New Intuitions for Cultured Meat

Is anybody working on solving the problem from the other direction, by e.g. genetically modifying chickens so that they don't have brains? ETA: I vaguely recall stories of chickens surviving for weeks with their heads chopped off; people fed them through their open throat. Gruesome, but also  evidence that something like this should be possible.

I work in bioprocessing, and overall wasn't that impressed by the Humbird report. The plant Humbird proposes looks nearly exactly like existing bioprocessing plants for biologic drugs. It shouldn't surprise anyone that trying to make (cheap) food isn't possible using plants that are designed to make extremely high value drugs. Let's take insulin, a relatively cheap biologic drug. One unit of insulin (0.035 mg) retails for about $0.30. Let's assume during the fermentation we get 20% cell weight, 10 g insulin/L, and have a 50% downstream yield. This means that we have 1.4 mg of cell mass per unit of insulin, for a cost of ~$0.20 per mg cell mass, which is $200,000 per kg. A reasonable target for cultured meat might be a retail price of $20 / kg. We are talking a 10,000x difference here, so it's clear to me that a cultured meat plant will need to be drastically different than an insulin plant or an antibody plant. To be fair, I'm not exactly sure what the ideal design would be, just that any plant that looks exactly like a biopharma plant (as Humbird assumes) is not feasible.

Keeping things sterile would probably be the hardest element to scale up for culture meat production in my opinion. Equipment/media sterilization is only sufficient if you run a completely closed process. However, keeping your process completely closed is quite difficult, especially if you are using fixed stainless steel equipment. You are eventually going to have to open up your equipment for cleaning and turnover, and you need literal 100% sterility. Even a tiny bacterial contamination will likely spread to contaminate your whole line, since bacteria grow so much faster than animal cells.

Due to these challenges, basically every biopharma plant uses large sterile suites where the rooms have ISO  7/8 quality air. This is really expensive, and was one of the major expenses in the Humbird report. 

However, where all the existing TEAs fail in my opinion is by ignoring single-use materials. It is potentially possible to have a truly closed system using single-use materials (i.e. plastic flowpaths and bioreactors) that are pre-assembled and pre-sterilized. This would allow you to put this process in a plant with more minimal air purification, which drastically reduces your costs. Single-use bioreactors (SUBs) also have drastically lower capital costs compared to stainless steel, something like 70% lower. The downside of course is that your consumables costs as you need to purchase these plastic bioreactors. As of right now, they also don't make 20k L SUBs, the largest I've seen is 6k L. I imagine larger SUBs would be doable if there was sufficient demand.

I wrote a comment in a previous discussion about why I think cultivated meat can be expected to become at least as efficient/cheap as animal-based meat: https://forum.effectivealtruism.org/posts/y8jHKDkhPXApHp2gb/cultured-meat-a-comparison-of-techno-economic-analyses?commentId=MJtLFZya2WqdNADSy

The basic idea is that animals were not evolved to maximize meat production. Just like horses were not evolved to maximize transport efficiency and hence were replaced by cars, plants were not evolved to maximize turning solar energy into electricity and are replaced by more efficient solar panels, pigs were not evolved to maximize insulin production and were replaced by recombinant-DNA yeast,...

I think this is a bit of a straw-person. It may be true that some commentators overstate the immediate relevance of this consideration, as well as how close companies are to reaping the benefits of this efficiency. However, a more charitable interpretation of the argument is that at scale, support systems will be amortized over a much larger amount of desired output. To give two examples:

• Animals expend a substantial amount of calories thinking with their brain. This processing will be centralized, and paired down in scope in the computers that run the bioreactors.
• Animals spend a lot of energy regulating body temperature. Given that bioreactors will be much bigger than animals, they will have a much lower surface area for heat transfer.

(To be clear, I don’t think this category of argument is a major consideration in favor nor against the feasibility of cultured meat. There are arguments pointed in both direction. One disadvantage of bioreactors is that they have to be designed to last decades, have modular components that can be swapped out, etc.)

I'm pretty confused by your paragraph describing the "futuristic bioreactor". It doesn't seem like we want almost any of those features for cultured meat.

The only parts that seem like they would be needed in are "[...] assembling those molecules into muscle and fat cells, and forming those cells into the complex tissues we love to eat" and "It has precise environmental controls and gas exchange systems that keep the internal temperature, pH, and oxygen levels in the ideal range for cell and tissue growth"

Some (though not all) of the others seem like they might be useful if we were to try and make cultured meat production as decentralizable as current meat production (and far more decentralized than factory farming).

EDIT: This analysis is probably wrong, see the reply. Leaving post up for context. 

One other comment, related to the Twitter thread that brought me here showing that poultry is 13% efficient at conversion of feed into meat. While this is true, feed costs are a pretty minor cost at least for poultry: NC-Choices-NC-Farm-School-Meat-Chicken-Info-graphic-Breakout.pdf (ncsu.edu)

I'm seeing the cost for conventional feed as $0.89 per lb poultry, compared to total costs of $6.42 per lb, so the feed is only ~14% of the total cost per lb poultry. I suspect that the feed cost is probably far higher for cattle, but that's because cattle are only about 3% efficient in terms of calorie conversion, far less efficient than poultry.

Admittedly, I do agree with your general argument, at least when it comes to poultry. It will be tough to be more than 13% energy efficient for cultured meat. However, the other costs of poultry production are high enough that is still seems reasonable that a cultured meat could still be competitive.