Here's my easy guide to making your own powdered vegetable bouillon:
Gather a variety of vegetables.
Choose an assortment of vegetables. The goal is to create a nice balance of flavors, similar to making a good broth. I typically use tomatoes, onions, garlic, mushrooms, carrots, peppers (both bell and hot), and fresh herbs (parsley, basil, and oregano are my favorites). Any vegetable will work; however, use caution with strong-flavored items like cabbage or Brussel sprouts ... they can overwhelm your mix. Similarly, be careful if you're adding beets ... their vibrant color, while beautiful, may not be appropriate in all recipes ... a little goes a long ways. If you like your bouillon to have a slight thickening affect, add in a potato and/or peas. As a general rule, use the vegetables and flavors that you like.
Wash and slice
Wash the vegetables thoroughly, peel if necessary, and slice thinly. A Mandoline works great for uniform, thin slices. One can also use a food processor or a knife. The thinner the slices, the faster the pieces will dehydrate. Depending on how you'll dehydrate the vegetables, shape may matter. For example, the shelves in my dehydrator have openings to allow the air to circulate. Smaller items, like garlic, will fall through the openings. To alleviate the problem, one can often slice a vegetable into strips rather than rounds. When this isn't possible, line the shelf with a parchment paper.
Choose a method (the oven, a dehydrator, or the sun). For a good discussion on various techniques, read How To Dehydrate Food. I use a dehydrator. While it does use electricity, it supplies consistent heat and dries food quickly. I have also used the solar method ... it works, uses no electricity, but is less heat consistent ... food is much more likely to mold if there isn't constant heat.
When you've chosen your method, lay the vegetables out in a single layer and begin drying. Continue dehydrating until vegetables are completely dry. They should be a bit crispy to ensure that there is no moisture left in them. Moisture will make your finished product lumpy and increase the possibility of mold.
Grind the dehydrated vegetables into a powder. One can use a food processor, mortar & pestle, or (my favorite) a coffee grinder. At this point you can add in a bit of salt and pepper, if you wish.
Note: I recommend not adding salt or pepper to your bouillon mix. Doing so limits the amount you can use in your recipes. Instead, add the bouillon to your recipe and then add salt/pepper to taste. In this way, you'll have much more control of your meal's sodium content.
Store the finished product in an airtight container, preferably glass. Similar to spices, a cool dark location is best for maintaining the quality of your bouillon.
Use your bouillon powder, mixed with water, as a soup base. Add it to stews, sauces, and gravies for additional flavor. Try a spoonful in your mashed potatoes or sprinkle it on a green salad. You are only limited by your imagination.
Homemade bouillon powder is easy to make, healthy, economical and delicious. I hope you'll give it a try!
Images courtesy of Michelle Meiklejohn, stockimages, John Kasawa, patpitchaya, artur84, and rakratchada torsap / FreeDigitalPhotos.net