[Inverted Passion] Challenges of producing cultivated meat at scale

Challenges of producing cultivated meat at scale

Raising and slaughtering 80 billion animals a year for meat obviously generates a lot of suffering in the world. Factory farms are not what animals evolved for, so the unnatural conditions in which they’re raised very likely induces suffering and pain in the raised livestock.

Plants and single cells likely aren’t conscious or experience pain the same way we or other animals do. So it makes sense to explore creation of alternatives of animal-derived meat from plants or cells.

Plant based meat is being explored by startups such as Impossible Foods or Beyond Meat. They are growing fast and are likely to make a significant dent on meat consumption. But some people prefer meat that’s not plant based and for them cultivated meat (that’s grown in bioreactors) could represent a viable option as a replacement of animal derived meat.

Cost of cultivated meat

The process of cultivated meat is simple: you take a small tissue sample containing stem cells from an animal (carefully and with minimal invasiveness). Grow such cells in a bioreactor and then push them to differentiate into muscle and fat cells. Then harvest these cells to make meat.

To be price competitive, cultivated meat needs to match the cost of animal derived meat. As of today (in 2022), animal derived meat in the US costs about $4/lb while it’s estimated that cultivated meat today costs $10,000/lb at lab scale.

Realistically, the latest news is that one of the startups (Future Meat) has brought down the cost of one pound of cultivated chicken breast to $7.7 per pound which is double the cost of animal derived cultivated chicken breast $3.2/lb. (However, it should be noted that Future Meat mixes plant protein in their product to bring the cost down and they don’t reveal how much of the entire thing is plant protein.)

The key question is: why is cultivated meat expensive to produce and will it ever be cost competitive to the animal derived meat?

Economies of scale for cultivated meat

Making cultivated meat in lab is easy. What’s really hard is making it at scale at a price that’s competitive to traditional meat.

When it comes to cultivated meat, there are essentially three levers of price reduction via economies of scale:

• Reduce price of growth media
• Increase density of cells
• Build larger bioreactors

Let’s explore these three in detail.

Reduce price of growth media

Cells require a medium for growing: micro and macro nutrients such as glucose source and amino acids. But mammalian cells also require certain growth factors (which are supplied by animal’s organs). These growth factors and recombinant proteins (like insulin, transferrin, etc.) are currently very expensive (some cost millions of dollars per gram).

Admittedly, these high prices are because current production methods require pharmaceutical grade purity but it is certain that reducing the cost of growth media will require breakthroughs.

Increase density of cells

The cost of cultivated meat directly depends on how many cells we’re able to produce per unit of bioreactor volume. Mammalian cells automatically regulate their growth rate at a certain density as they produce waste / catabolites (which serve as growth limiting factors).

If we increase the density of cells somehow, we can reduce the cost but pharmaceutical industry has been trying to do the same (for increase production of recombinant proteins they produce). Increasing cell density beyond what’s currently the norm will require breakthroughs.

Build larger bioreactors

Mammalian cell culture requires extreme sterile conditions because they grow much slower (doubling time 24 hours) than bacteria or yeast (doubling time 20 minutes). So any bacterial, yeast or viral infection can quickly take over the entire culture medium and render it useless.

Maintaining sterile conditions costs money which is directly proportional to volume/area that needs to be made sterile. So it makes sense to build one giant bioreactor rather than multiple small one. (The additional benefit is that one giant bioreactor uses less material, labor, sensors, etc. thus saving costs).

However, we can’t keep making larger bioreactors because:

• Cell culture has to be stirred for oxygen supply and stirring in giant bioreactors creates shear stress on cells that can explode
• Contaminations spread in one giant bioreactor wastes a ton of feed + lose time, v/s if contamination is spread in one small bioreactor among many

These constraints provide a limit to how big we can make bioreactors for cell cultures. Unless a breakthrough happens in bioreactors, we may be stuck with relatively smaller bioreactors which hinder economies of scale.

Deconstructing bioreactors and animals

Different functions that are needed to support cultivating meat in bioreactors happen in animals as well. Let’s take a look at what bioreactors do that animals also perform:

• Digestion
  • Bioreactor: requires pre-digested amino acids and sugar source (such as glucose)
  • Animal: stomach does this job
• Growth factors
  • Bioreactor: requires addition of purified growth factors (such as insulin and IGF-1)
  • Animal: organs such as pancreas and liver produce these
• Sterility (protection from viruses and bacteria)
  • Bioreactor: requires cleanroom conditions and/or antibiotics
  • Animal: has its own immune system
• Waste filtration
  • Bioreactor: requires additional processing steps (continuous or batch)
  • Animal: has kidneys to do the job
• Oxygen supply / CO2 removal
  • Bioreactor: stirrer and air pumping
  • Animal: has blood
• Temperature regulation
  • Bioreactor: requires active management of temperature
  • Animal: does so through perspiration

In essence,

for trying to grow muscle cells, we are required to reintroduce many functions that animal body naturally does (excluding, and most importantly, the brain).

This would automatically increase the cost since we will be required to essentially recreate what evolution honed to do efficiently for millions of years.

Something as simple as a growth factor (which costs millions of dollars per gram) is produced for “free” by the animal body and circulated to grow all the cells (including the muscle cells). The cost is increased for externally supplied growth factors because we need to purify it.

Pharmaceutical industry as a benchmark for limits on cultivated meat

Mammalian cells have been cultured for quite some time now. Many recombinant proteins used as treatments are produced by chinese hamster ovary cells (and other mammalian cells). The pharmaceutical industry has poured billions of dollars into research to optimize efficiencies of growing these cells, so the current production limits from that industry should be taken as serious roadblocks that cultivated meat companies can’t go past (barring breakthroughs).

The total bioreactor capacity for cultivating mammalian cells stands at 20-30 million litres, which is a minute fraction of what will be needed for cultivated meat industry if it is to make a serious dent into existing meat supply chains.

Where will this extra capacity come from?

Economic hurdles towards investing into cultivated meat

Extra manufacturing capacity for cultivated meat can only happen if investors see possibility of making good returns. Large plants can easily cost in the range of $500mn.

Unfortunately, this level of funding doesn’t seem to be the case because:

• Meat industry is a commodity industry with razor thin margins
• Given thin margins, amortisation of returns are expected to happen over 25-30 returns and not 5-10 years that most investors want

TLDR

In summary:

• Cultivated meat requires several breakthroughs to achieve cost-parity with conventional meat
  • Breakthroughs in bio for increased cell density, bioreactor design for sterile conditions, cheap growth media
• Even with breakthroughs, scaling up inputs (such as growth factors, amino acids, bioreactors) can not happen fast enough as the supply chain isn’t ready for this level of scale
• Cultivated meat companies may not be economically attractive to be able to generate funds needed for manufacturing at scale
  • Especially given that the alternative for it (conventional meat) is both cheap and abundant, and when you account for plant based alternatives, not enough demand pressure for cultivated meat is there

What is more likely:

• In the pursuit of cultivated meat, we will end up having some major breakthroughs which will help us in manufacturing artificial organs or other such high-valued bio products for which alternatives don’t exist (instead of meat for which alternatives exist)

Further reading

• Lab-grown meat may never be cost-competitive enough to displace traditional meat
• HN commentary on the article above

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