Last time I wrote about warehouse savings on Cheddar cheese. I’m planning on doing a few more food comparisons for you, but today I want to take a detour and talk about freezer bags.

My warehouse club frequently offers coupons on boxes of Ziploc brand plastic freezer and storage bags. And whenever I see one of these coupons, I clip it right away. They are a fantastic deal. Remember, I buy only national, name-brand plastic food products because they have all pledged not to use Bispherol-A, or BPA.

So two weeks ago, I took advantage of the $2.00 off coupon on Ziploc quart freezer bags my warehouse club was offering. I bought a large multi-pack box for $6.89, after the coupon. The large box contains 216 bags, which brought my per bag cost to 3 cents each. (And truth be told, I bought the coupon limit. Since oil is going up and plastic is a product derived from oil, I figure it’s only a matter of time before prices increase.)

Next I checked out prices at the no-frills grocery store. There, the largest box of Ziploc brand quart freezer bags was $4.73 for 40 bags. If i used my “save $1.50 on 2″ coupon, each box would cost $3.98 or 10 cents per bag.

Next I checked out a local supermarket that allows double coupons. Their 40 bag box retails for $5.99. With my coupon, that box would be $5.24. Adding the double coupon (up to 50 cents face value), brings the final box cost to $4.74, or 12 cents per bag.

A new coupon book for my warehouse club arrived in my mailbox recently with a coupon for gallon freezer bags. Because these bags are 3 to 4 times MORE expensive at the grocery store, even after I factor in coupons, I will be stocking up. You may want to also.

I often get asked how much you really can save at the warehouse club. Since I shop there a lot and collaborated on a book about how to get the most from your money spent there, I think it’s a fair question.

A. You can usually save between 20-50% on most food items. I dislike giving a range like this, but depending on where you shop, your savings will vary a lot.

For example, last week I bought the 5 pound bag of shredded Cheddar cheese at my warehouse club for $12.39. Divided out, it yields (roughly) ten 8-ounce bags that keep well in the freezer. My per bag my cost is $1.24.

I even got the camera out and took a few snaps to show you what I mean and what I did. I’m no Ansel Adams, but hopefully they get the point across.

I was able to compare my packages to the same size, same brand package of shredded Cheddar carried at 2 local stores. One store is a no-frills establishment, where you bag your own groceries and rarely see a clerk floating the aisles, assisting customers. Their price for the same 8-ounce bag was $1.98.

The second store is a one-stop model, where you can purchase groceries, clothing, hardware, toys, etc. Their price was $3.49. See what I mean about price variations?

Is that incredible or what? So depending on where I shop, I can save anywhere from $0.74-$2.25 PER bag. Now multiply that by 10 and you see that by buying in bulk and dividing the package myself, my savings range from $7.40 to $22.50.

Remember, if you don’t have the freezer space for 10 bags, seek out one or more friends that are willing to split it with you. The money you save will make the effort well worth while.

Everybody is talking about plastics. Our local paper carried an article describing which to use and which to avoid. Nutrition Action Newsletter did the same in their latest issue. And, last week the Canadian government banned certain plastic products from containing BPA (bisphenol-A).

Our readers are concerned too. We received a note from Stephanie, who shared her thoughts about plastics in our book. Thank you, Stephanie, for bringing this up. I always appreciate the opportunity to chat with readers! Here’s what she said:

Great book and recipes. The only issue I have is environmental. I’m concerned with encouraging people to use plastic freezer bags. Have you considered containers? This obviously takes up more room but we ALL need to reduce or stop using plastic bags entirely. Please consider this as you tour and present your recipes/methods.

I share many of Stephanie’s concerns. As I mentioned in the email response to her, the question of plastics use did come up, it was discussed at length, and was a difficult resolution.

Unfortunately, the reality is that plastic bags are the most reliable, convenient, and economical way to store your food in the freezer for most recipes. Even now, I hesitate to offer other container solutions because of the increased risks of freezer burn and entire meals going straight to the landfill (which is not optimal environmentally or ethically, for that matter, given the current global food crisis).

As I mentioned to Stephanie, because plastics are derived from oil the market incentive for widespread plastics recycling is building. Here in the Portland, Oregon metro area, I recycle all of my plastics–everything from my rinsed freezer bags, to broken plastic lawn chairs, to old baby pools. Be on the lookout in your area too.

In the meantime, please consider these 5 tips:

• Stick with the national brands of freezer bags and do NOT cut corners by purchasing less expensive store brands. Unless they say they do not use BPA in their products, that is. We first advised readers of this 2 years ago (phew, am I glad!).

• Switch to reusable glass containers. But be sure that the size fits the portion to be frozen well and the seals are tight. Aim for 1/2 inch head space (the area between the rim of the container and food surface). I’ve noticed that Lindsay’s Chicken Curry fits perfectly in medium-sized Pyrex brand containers. The lids are not tight enough to prevent freezer burn, however. So consider using a layer of freezer paper, aluminum foil, or plastic wrap to enhance the seal.

• Store reusable containers on the lower shelves of your freezer. They are heavier and tend to be a solid block. If dropped from higher shelves, they will shatter, crack, or break. Not to mention really hurt your toes :)! Also, plan for these blocks taking longer to thaw in your refrigerator.

• Do not wash plastics in the dishwasher. Experts caution, that the detergents and temperatures weaken the plastic, thereby increasing the risk of chemicals leaching into food. I’ve noticed the plastic does become weaker and breaks easier (see above). It’s just as easy to wash them by hand with hot soapy water.

• Reuse plastic containers when appropriate. DO NOT reuse old cottage cheese or margarine tubs in the freezer. The plastic and seals aren’t designed for it. Buy containers meant for the freezer. DO refill clean plastic milk jugs (3/4 full) with water and place in your freezer. The back corners of shelves are good places where they can’t easily fall out. A full freezer doesn’t use as much energy or work as hard to keep cold. And if you have a power outage or your freezer stops working, they will help keep everything cold longer.

Please keep writing in! Lindsay and I do our best to respond and always enjoy hearing from readers. And many thanks to Stephanie for her email.

Q. I was reading your blog A Comparison of Cost and Convenience (December 5, 2005) and you said the Tray Pack method was clearly the best choice financially, but it looks like the second description - making a month of meals at home - is much better than the third - the Tray Pack method. I was very curious about this and wanted to get the correct figures if they are wrong.

A. I made the comparison for two reasons - cost and convenience. While it can be more economical to cook a month of meals at once, it is also much more labor intensive. For the best combination of economy and labor, we suggest the Tray Pack method.

Q. Do I drain the beans before using them in the chili?

A. I always just dump the beans in, liquid and all. I know some people like to drain and rinse the beans but I’m too lazy for that Either way will work just fine in chili.