Material Insights · Understanding the Material World

Bioethanol and Maize

Maize is the main feedstock for US ethanol, with about a third of the 2025/26 US crop expected to go to distilleries, and India turned into a maize importer in 2024 as its distilleries switched to maize. Just under a third of each tonne returns to the feed market as distillers grains, so ethanol and livestock compete for, and share, the same grain.

Bioethanol (chemical) and Maize (commodity): 4 relationships.

How they are linked

1. Feedstock

Physical flow · Strong · Maize to bioethanol

Maize starch is broken down by enzymes into glucose that yeast ferments to alcohol, and maize is the cheapest abundant starch in the US and, increasingly, in India.

  • 5.6 of 17.0 billion bu US corn for ethanol against the 2025/26 crop, about a third
  • 45.68% maize share of India's first ESY 2025-26 ethanol allocation

In the US, ethanol is the second largest use of corn after feed, at 5.6 against 6.2 billion bushels in 2025/26. In India maize overtook cane juice and molasses as the main feedstock in only a few years, as oil companies awarded grain distilleries the largest share of supply tenders. In both countries a poor harvest raises distillery feedstock costs while blending obligations keep demand fixed.

Sources: USDA Economic Research Service; ChiniMandi

2. Distillers grains

Joint production · Medium · Ethanol plants return feed to the maize market

Fermentation uses only the starch, so the protein, fibre and oil leave the plant as distillers dried grains with solubles (DDGS), a livestock feed.

  • just under a third tonne of DDGS per tonne of corn processed
  • 12 Mt US DDGS exports in 2013/14, up from nearly zero in 2005

Because about a third of the mass comes back as feed, the net claim of ethanol on the feed supply is smaller than the gross figure. DDGS sales link distillery margins to soybean meal and other feed prices, and exports of DDGS spread the US ethanol industry's feed output into world markets.

Sources: USDA Economic Research Service

3. Price link: product made

Cost and price · Strong · Both ways

Corn is the largest cost of US ethanol, so a lasting rise in corn prices lifts the ethanol price, but blending rules and petrol prices also move ethanol from month to month.

  • 0.26 monthly change correlation
  • 0.70 12-month change correlation
  • 0.92 fitted elasticity

The loose monthly link and strong yearly link fit a market where ethanol responds first to petrol demand, credit prices and export orders, and only over a season to feedstock costs.

Sources: Material Insights (World Bank, FRED, IMF data)

4. India's E20 pull on maize

Policy · High in India · Indian ethanol policy turned maize trade around

India's push to 20% blending made maize the main grain feedstock for new distilleries, and their demand outran domestic supply.

  • about 1 Mt record maize imports expected in 2024, from Myanmar and Ukraine
  • 3.5 Mt maize used for about 1.35 billion litres of ethanol in 2024

India usually exported 2 to 4 Mt of maize a year, but in 2024 exports were expected to fall to about 0.45 Mt while imports reached records, with a 50% duty and a 15% concessional quota for about 0.5 Mt. Domestic maize prices rose far above world benchmarks, hurting poultry farmers, for whom feed is about 75% of costs.

Sources: BusinessDay (Reuters)

For investors

Key learnings

  1. Blending mandates make ethanol a largely fixed claim on maize, so in a short harvest feed users and exporters lose volume while distillers pay higher prices to keep running.
  2. Distillery margins depend on the spread between ethanol plus DDGS revenue and maize cost, not on maize prices alone.
  3. India's switch to maize ethanol has created a new, policy-driven demand that pushed Indian maize prices far above world levels in 2024, and import rules decide how long such a premium can last.

What to track

  • US corn used for ethanol: A rising share signals tighter feed and export supply (Monthly · USDA WASDE and Grain Crushings report)
  • Indian maize prices against import parity: A wide premium shows distillery demand outrunning supply (Weekly · Agmarknet, NCDEX)
  • Ethanol crush spread (ethanol plus DDGS less corn): A narrowing spread warns of distillery run cuts (Weekly · USDA AMS bioenergy price reports)

For policymakers

Key learnings

  1. India's ethanol programme has made maize a fuel crop, which raises farm incomes but lifts feed costs for poultry and dairy.
  2. Import policy, including the 50% duty and the tariff quota, now decides whether ethanol demand is met at home or abroad.
  3. Feedstock diversity across maize, rice and cane lets India shift supply between crops when one harvest fails, if pricing allows it.

What to track

  • Feedstock shares in oil company ethanol allocations: A rising maize share means more pressure on feed markets (Per tender cycle · Oil marketing companies, Ministry of Petroleum and Natural Gas)
  • Maize imports and duty concessions: Larger quotas signal domestic shortfall (Monthly · Department of Commerce trade data)

India

India made maize the largest single ethanol feedstock within a few years and turned from a regular exporter into an importer in 2024, so maize prices are now set as much by fuel policy as by feed demand.

Sources

  1. Price correlation, Material Insights, Material Insights (World Bank, FRED, IMF data)
  2. Feed Outlook (FDS-26a), USDA Economic Research Service (2026)
  3. Charts of Note: corn use for ethanol and distillers grains exports, USDA Economic Research Service (2015)
  4. ESY 2025-26: OMCs allocate around 1048 crore litres for ethanol supply; maize holds share of around 45 per cent, ChiniMandi (2025)
  5. India shakes up global maize market with ethanol drive, BusinessDay (Reuters) (2024)