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If you’re trying to eat healthier foods, you’ll find that a lot of recipes for baked goods add either wheat bran or wheat germ to jack up the fiber content. There are some differences between the two nutritionally, but the germ and bran are similar enough that you can use them interchangeably without it making a noticeable difference in your recipe.

A Quick Lesson in Grain Anatomy

Every grain of wheat, or any other grain, for that matter, is a seed. It’s designed to grow a new wheat plant, and its anatomy is shaped by that basic fact. Botanists and plant biologists are happy to go into a lot more detail on the subject, but you can think of each seed as having three parts.

The outside is a tough, fibrous layer that’s meant to keep the seed from rotting before it can sprout. The bulk of the grain is the starchy middle, which serves as a food store for the new baby plant as it sprouts and grows. Finally, there’s the part, the “seed of the seed,” so to speak, which actually becomes the new plant. The whole thing is very much like an egg, with its protective outer shell, large quantity of white and relatively small yolk.

In this case, the “shell” is the tough bran, the “white” is called the endosperm, and the “yolk” is the wheat germ. The endosperm is the part that’s used to make white flour, so the bran and germ are milled out and sold separately.

Wheat Bran vs. Wheat Germ

The difference between wheat germ and wheat bran largely comes down to their ratios of protein, fiber and lipids. Bran contains about 15% protein by weight, a little over 4% fat, and over 42% dietary fiber. The germ is richer in protein, at about 23%; has more than double the fat, at 9.72%; and contains about 13% fiber. Largely because of its higher percentage of lipids, the germ also packs 360 calories per 100 grams compared to the bran’s 216 calories.

If you shift your focus to the micronutrients, or vitamins and minerals, the differences between the two are relatively minimal. Both contain a number of useful minerals, notably, zinc and iron, and B vitamins, including niacin, thiamine, riboflavin and B-6. The exact proportions of those nutrients vary somewhat, but each packs enough fiber and nutritional punch to make it a worthy addition to your baked goods.

Baking With Wheat Bran or Germ

Both wheat bran and wheat germ are normally used in baking for their fiber content. Bran is a signature ingredient in breakfast muffins, for example, and it’s often added to bread and rolls to increase their fiber. Wheat germ isn’t something you’ll see as often, but when it does appear in recipes, it’s generally used in much the same way.

If you find yourself mid-recipe and discover there’s no bran in the house, wheat germ is a straight-up wheat bran substitute. If your recipe calls for 1/2 cup of bran, you can use wheat germ instead, and the recipe should turn out just fine. The same holds true in reverse, with bran making a perfectly good wheat germ replacement for baking purposes. Either wheat germ or wheat bran also can be used as an oat bran substitute, if that’s what your recipe calls for.

Storing Wheat Bran and Germ

Both wheat germ and wheat bran can be stored in your pantry at room temperature, but ideally only for a relatively short time. Those natural oils in the bran and germ are healthy fats, but they’ll also turn rancid over time.

Because of its lower fat content, wheat bran is more durable. If you use it regularly and buy more every few months, it’s OK to keep it at room temperature. If you take a year or so to use it up, you should probably find room for it in the fridge or freezer instead. Wheat germ is more perishable, and it can become rancid in as little as a few days in a warm climate. It’ll last a week or two in the fridge, but for longer storage, you’ll need to pack it in an airtight bag or container and freeze it.

Either bran or germ can add an unpleasant flavor to your baked goods if they’re rancid, so give them the “sniff test” before you bake. If they smell sharp, sour or unpleasant in any way, it’s best to discard the old package and buy new.