The time has come for Congress to rethink ethanol, an alternative fuel that has lately fallen from favor. Specifically, it is time to end an outdated tax break for corn ethanol and to call a timeout in the fivefold increase in ethanol production mandated in the 2007 energy bill.

This does not mean that Congress should give up on biofuels as an important part of the effort to reduce the country’s dependency on imported oil and reduce greenhouse gas emissions. What it does mean is that some biofuels are (or are likely to be) better than others, and that Congress should realign its tax and subsidy programs to encourage the good ones. Unlike corn ethanol, those biofuels will not compete for the world’s food supply and will deliver significant reductions in greenhouse gases.

Last year’s energy bill required that 36 billion gallons of biofuels be produced annually by 2022. Of that, 21 billion gallons would be “advanced” biofuels that are still mostly in the experimental stage; the rest would be the corn-based variety beloved by farmers, Midwestern politicians and presidential candidates. This mandate comes on top of a 51-cents-a-gallon subsidy to ethanol blenders enacted when the industry was small and oil prices low.

The industry is no longer small  seven billion gallons and climbing rapidly  and oil is over $120 a barrel, making ethanol not only competitive but a bargain.