Many markets took as positive an announcement by the US Federal Reserve of further move to prop up the world's biggest economy.
The US central bank's commitment to an extra $45bn of monthly US government bond purchases helped the average commodity, as measured by the CRB index, to 0.5% gains.
But, again, grains were not doing their bit to support the complex, despite positive talk from Goldman Sachs and Bank of America Merrill Lynch, but continued instead to feel pressure from concerns over US exports.
The US Department of Agriculture on Tuesday crystallised concerns over US wheat exports by cutting its forecast for America's shipments in 2012-13, citing strong competition from other origins.
Disappointing US corn exports have been a running sore throughout the early months of the season.
'Funds continue to liquidate'
"The Fed's announcement sparked buying in the metals and the energies. But it has not had much impact in the grain and oilseed markets,"Darrell Holaday at Country Futures said.
"Funds continue to liquidate long corn and wheat positions as they are in 'give up' mode as those contracts continue to make new lows daily."
In fact, not all the grain export news was downbeat, with Benson Quinn Commodities noting "a glimmer of hope" in that South Korea may have purchased a cargo of US corn for April-May delivery, although South Africa was "also mentioned as a potential origination point".
South Korea is a particularly sensitive spot in corn export markets as the country's largest feedmaker, Nonghyup Feed, excluded the US from its latest tender in a wish to diversify suppliers.
In wheat, US supplies of soft varieties are "now offered at a sharp discount, of about $15 a tonne, to European Union offers", Benson Quinn said.
This "should limit the recent pattern of EU wheat offers at prices below replacement costs", the broker said, even as France, Europe's top wheat producer, raised hopes for shipments of wheat to customers outside the bloc.
However, US Commodities said that the ongoing wheat harvests in Argentina and Australia "will continue to anchor wheat on rallies", if the market manages any.
And, indeed, while Chicago wheat for March did manage to recover temporarily to positive territory, it ended down 1.2% at $8.12 a bushel, its weakest finish since early July.
French wheat did better, losing a more modest 0.2% to E261.25 a tonne for January, given some support by export data, while London's May lot shed 0.5% to £223.00 a tonne.
'Lots of corn yet to sell'
Corn did a little better, underpinned by weekly US ethanol production data which, while showing an 11,000-barrel-a-day drop in output, were still deemed "solid" by Mr Holaday.
Indeed, at 824,000 barrels a day, ethanol production was still on course (depending on which analyst you ask) to meet targets needed to meet US Department of Agriculture projections for corn usage in biofuels in 2012-13.
Still, the export news weighed, with RJ O'Brien noting the persistent competition from South American supplies, with Brazil having "lots of corn yet to sell for January-February".
Corn for March dropped 0.4% to $7.25 ½ a bushel.
Export data ahead
Yet again, it was left to soybeans to fly the banner for bulls, rising – only by 0.1% to $14.73 ½ a bushel, but rising nonetheless,
An unknown buyer of more than 2,000 soymeal contracts was credited with boosting the complex. And indeed, soymeal itself for January closed up 0.9% at $452.00 a short ton.
Furthermore, with US soybean shipments still thriving, there was a reluctance to sell ahead of fresh US export sales data on Thursday.
"A surprise today would be more fund selling in beans ahead of tomorrow's export sales report," RJ O'Brien's Richard Feltes said earlier on.
Benson Quinn forecast that "the trade will want to own soybeans and meal late in the session ahead of weekly export data to be released tomorrow morning".
'Upside price potential limited'
Among soft commodities, cottonmaintained its rise, helped by the downgrade on Tuesday by the USDA, of 400,000 bales to 5.4m bales, in the estimate for US stocks at the close of 2012-13.
OK, not everyone saw the revision as "bullish", as Rabobank did. Luke Mathews at Commonwealth Bank of Australia said that "US cotton inventories are still 1.8-times larger than the prior three-year average meaning any upside price potential should be limited".
But New York's March contract rose 0.3% to 75.12 cents a pound nonetheless, the highest finish since late October.
However, New York arabica coffee and raw sugar both closed at two-year lows, depressed by Brazilian production which has, for both commodities, beaten early-season expectations.
Even a downgrade by Conab to its estimate for Brazilian sugar output left its figure above consensus forecasts.
Coffee for March fell 2% to close at 246.50 cents a pound, the lowest finish since June 2010, while raw sugar for March fell 1.8% to 18.54 cents a pound, the weakest settlement since August 2010.