Gas prices get the headlines, but grocery costs have quietly been rising in recent months.

The ethanol boom has increased prices in most American supermarkets. As farmers plant more corn, they plant less wheat and beans, which lowers supply and boosts prices. Fewer soybeans mean more expensive animal feed, which raises the price of meat and dairy. Milk prices are at record-highs as demand soars while international government surpluses dwindle.

Average consumers can fight back against price increases by shopping at markets that offer the lowest available prices. Where can you shop for food in Chicago to get the best deals?

To answer this question, I selected 12 “standard” food products from six food stores. I recorded the “normal” price for each item. In other words, I did not include any daily or weekly sales or discount prices with shopper cards. For example, a 12-pack of Miller Light would have been $6.99 at Jewel with the Jewel-Osco Preferred Customer card, but the normal price (the one I used for this study) was $9.99.

For certain products, I chose a common brand name (e.g. Tropicana orange juice) and compared prices at each store using a standard size (e.g. 64 oz). For other products, I recorded the cheapest available offering (e.g. tuna fish, wheat bread, eggs, milk). The least expensive choice was frequently, but not always, a store brand. I wanted to compare the lowest priced options at each location to find out the least amount of money a shopper could spend.

If a store did not offer a certain product, I entered in data as “not available.”

I conducted all of my research on Sunday, May 28, at the grocery stores located in River North and Streeterville. The only major supermarket chain without a presence in this area is discount grocery retailer Aldi USA.

The following were my results, in dollars:

*Organic broccoli

To make the results easier to compare, I calculated an average price for each product and made a new chart. I entered how much a supermarket’s item was above or below the average. For example, the average price of eggs for the six supermarkets was $1.69. Dominick’s price was $1.99, or $.30 above the average.

The last row calculates the average of the relative price differentials. Overall, Trader Joe’s is the best option for the price-conscious shopper. A typical product was 32 cents less than average. However, Trader Joe’s did not stock four of the 12 products selected and sold broccoli by the bunch instead of the pound (a "bunch" was approximately 1 lb). To be fair, the store typically offered a substitute product, which was usually significantly lower in price. Instead of Cheerios, Trader Joe’s offered an “O’s” cereal for nearly two dollars less. However, many of the other stores also offered cheaper “knock-offs.”

Thus, you should know that Trader Joe’s may not have exactly what you’re looking for. Nevertheless, among food staples like eggs and spaghetti, Trader Joe’s was consistently a low-price option.

Jewel was our second-place finisher, but if you own a Jewel-Osco Preferred Customer Card, which is free, it vaults into first place. While shoppers’ card discounts vary from week to week, prices at Trader Joe’s do not fluctuate. However, when accounting for weekly sales, Jewel is likely a less expensive option than any of our sampled stores.

Treasure Island and Dominick’s had similar prices and can be thought of as "average" priced markets, although if you're in the mood for cereal, shop at Dominick’s. It was the cheapest option for both milk and Cheerios. 

You’ll pay a bit of a premium at Whole Foods (especially for organic produce), but Whole Foods actually sells some brand name goods, like Tropicana orange juice, at a cheaper price than much of the competition. White Hen charges more for nearly all food products. Unless you’re in a hurry or at a location with no other options, it would serve your wallet well to avoid the convenience store.

So the next time you’re running low on food, while clipping coupons or scouting a sale at a large chain supermarket still makes financial sense, Trader Joe’s is the place for you if you’re looking to save a few dollars on the essentials.

But let’s be honest. I’m still going to shop at Whole Foods, because when it comes to free samples, it's the best game in town…