No, You Shouldn't Freeze Baking Spices. Here's Why
It's a serious inconvenience when baking spices go bad or deteriorate in flavor, and to prevent this, many people take to hacks for storing spices that don't always work as originally planned. Freezing your spices is one such hack. The idea is to keep your spices fresh long-term, but in reality, the freezer can ruin baking spices in ways you may not have foreseen.
The primary danger of freezing spices is water. Condensation can form inside your spice storage containers when the temperature changes drastically. This won't do much to your spices while they're frozen, but it can cause them to clump or even mold once thawed. Freezer burn is another worry. As your spices freeze, the moisture within them will be drawn out into the dry freezer air – yes, this is true even for dry spices. You'll want to prevent freezer burn at all costs as it can cause undesirable flavor changes.
The effort it takes to freeze spices for long-term storage probably isn't worth it for most spices. Even if they're stored properly in vacuum-sealed bags, they only last around six months before the flavor degrades. In comparison, properly stored spices can last up to three years.
Are there any spices you can freeze?
There is one exception to this rule: You can freeze spices that come from fresh roots, though it's likely that some of these will be used for savory bakes rather than a sweet cake or cookies. For example, fresh whole-root ginger, if packed in an airtight container or bag, can last for six to eight months in the freezer. Fresh turmeric, spice-adjacent garlic, and fresh leafy herbs may all last longer in the freezer, but you'll want to keep an eye out for freezer burn since these herbs and spices have high moisture content.
For your dry spices, if you want to freeze them it's best to vacuum seal them with a home vacuum seal kit for added protection. To be perfectly safe, though, it's best to skip the freezer. The optimal way to store them is in airtight containers in a cool dry place away from light. Make sure this area is relatively moisture-free and never use spices directly over hot food. It's also important to keep them away from heat sources since this can cause untimely flavor loss and spoilage. Otherwise, most prepackaged spices require no special prep since they're typically already dried with long-term storage in mind.