With the holidays fast approaching, now is the time to take stock. You’ll want your pie plates, bread pans, cookie sheets, thermometers and roasting pans ready to be put to work.

But just as importantly, be sure that your go-to leaveners are up to the task. It’s better to test them now rather than find out when things fall flat on Christmas.

If you’re a serious baker, you might be familiar with the superb blog on the King Arthur Flour website, which recently ran down how to test your baking powder, baking soda, active yeast and instant yeast to make sure they’re fresh enough to do the job. For more details, it’s worth a look.

Curious about my own leaveners, I ran them through the test, with mostly positive results. One of the less successful elements was the baking powder. Mine turned out to be pretty dead. If you use a lifeless leavener in your baking, the results could be jarring — biscuits that feel like bricks, cookies that are too dense and cakes without the elevation you had hoped for.

Here’s what I did:

Baking soda: This one is fairly immediate and dramatic. Put 1 tablespoon of cider vinegar in a small bowl or cup. Add a half teaspoon of baking soda. If the baking soda is working as it should, you’ll see a dramatic frothing of bubbles immediately. That’s the sodium bicarbonate reacting with the acid of the vinegar. Mine responded positively and is ready to be used in cookie, muffin and waffle recipes in the days ahead.

Baking power: Mix a half teaspoon of baking powder with 2 tablespoons of water. You should see ample bubbling activity, though not to the extent of the baking soda/vinegar, according to the King Arthur Flour blog. Baking powder is a combination of baking soda, cream of tartar and a touch of cornstarch, so there is already an acid present (and no need for vinegar in this test). My baking powder seems relatively lifeless, so I will be tossing the little that I have left and buying more soon. As I recall, I refilled my container with baking powder from a grocery store bulk bin, so I am unsure of the sourcing.

Active yeast and instant yeast: This is a pretty standard procedure for those who bake bread with commercial yeast (as opposed to a natural leavener, aka sourdough starter). In fact, many bread recipes call for the yeast to be mixed in warm water with sugar, or proofed, to awaken the yeast prior to mixing the dough. For this test, use a half cup of warm water and a half teaspoon of sugar in two separate cups. Then stir in a teaspoon of active yeast and instant yeast. After about 10 minutes, there should be lots of bubbling and lift visible in both cups.

If you’re planning to make yeast rolls or breads for the holidays, test your yeast now. There’s nothing worse than finding out your yeast is DOA when that special dinner is looming. If you use your yeast infrequently, it’s OK to store it in the fridge in a sealed sandwich bag. Use a Sharpie to jot down the date you opened it.

These are very helpful tests to perform every so often, and since this is the most intensive baking time of the year — and the stakes are usually the highest — what better time than the present to get out a bunch of cups and see if your leaveners can make bubbles?