I can't take the credit for this because I know I read about the idea somewhere out there on the internet, but I'm definitely glad I came across it. It's working very well for us, so I thought I'd pass it on!
I've read about a lot of people who use ice cube trays to freeze 1 oz. portions of food they have prepared, but I didn't have any ice trays, and 1 oz. is a bit on the small size. Instead of ice cube trays, I've been using silicone muffin cups. I was able to get a set of the Wilton cups at Michael's with a 50% off coupon, so they were around $5. I like the idea that they will serve another purpose when our baby food days are over. Plus they have a 2 oz. line that marks the inside. They are working fabulously, but I think I need to get another set, so I can make larger batches at a time.
The whole process is really pretty simple. First, you just choose whatever veggie you'd like to cook up to freeze. I've done carrots, green beans, peas, and sweet potatoes so far. The peas were cooked from frozen and the green beans were canned from my parents' garden.
First you'll want to prepare the veggies and cook them appropriately. I simply peel and chop the carrots. Then I cover them with water and let them boil until they are tender. Sweet potatoes are easily baked. Just wash them and poke them with a fork. Then you can wrap them with foil and bake them on a cookie sheet.
For beginning eaters, you'll want to use a food processor or something similar to chop up the cooked veggies. Then you may want to strain out any tougher pieces before you divide them into the cups. You can add in distilled water, breastmilk, or formula to create a thinner consistency as well. Benjamin is at the point where he wants more consistency to his food, so I usually just mash the carrots and sweet potatoes with a spoon. The green beans and peas still require a little extra chopping because of the tougher hulls, but I still don't strain them.
Once everything is all mashed or chopped up, you can then set out the muffin cups on a baking sheet. Simply spoon enough into each cup to reach the line on the inside. This way you will know that each portion is around 2 oz. Once you've filled the cups, place the sheet into the freezer to harden.
Later, you will take the veggies out of the freezer and easily pop them out of the cups. Place each type of veggie in its own freezer bag and label the bag including the date. When it comes time for a meal, you can just pop one or two cubes into a microwaveable bowl and heat in the microwave. I usually start with 30 seconds and then add on 15-20 seconds at a time stirring in between. Of course, this will depend a bit on the power of your microwave. Just be sure to check the food to make sure it isn't too hot, and stir well.
As you can see, Benjamin really loves the carrots, and it has definitely saved quite a bit of money. Consider that I was able to purchase a 5 lb. bag of carrots for about $4. About 7-8 carrots fill 12 2 oz. muffin cups. Stage 1 baby food usually comes in 2.5 oz. containers, and stage 2 is usually in 3.5 oz. containers. I've also found that the price on the stage 2 is typically $.45-$.50 or more per container.
I know that some people love their food mills to grind up food for baby. I do think there are times this can be very useful. For now, though, freezing food for Benjamin is working great for me.