Food Storage Shelf Life For PreMix Of Cakes And Breads

If you’ve ever considered (for your food storage) a premix of dry ingredients for breads, cakes, cookies, etc. and storing the combination in individual bags or mason jars (etc.) for storage purposes – here’s my opinion regarding potential long term food storage issues of a premix.

The dry premix ingredients will likely include some combination of flour, sugar, salt, baking powder, baking soda, dry milk, possibly powdered eggs, and yeast (for breads).

The wet ingredients (to be added later), although obviously not part of your premix storage, might include some combination of water, oil, shortening, butter, eggs, milk, and flavoring additives.

To determine the feasibility of a premix, we first need to look at the practical shelf life of the individual dry ingredients.

Shelf life depends on several factors including the method of storage, temperature of storage, and also what the manufacturer considers to be the threshold whereby taste, texture, and other parameters are negatively affected.


No problem for a premix. Commercial white sugar has an indefinite shelf life because it does not support microbial growth. Just store in a moisture-proof environment in a cool, dry place.

I have read mixed reports on the shelf life of brown sugar, with some manufacturers indicating an indefinite shelf life, while others indicate 6 months or a year. I’ve also read that apparently you should not vacuum-seal brown sugar because it can develop bacteria when in oxygen-free storage.

I would err on the side of caution and if you need to get your hands on brown sugar, simply make your own when needed by adding 3 ounces of molasses (by weight) with 1 pound of sugar.


No problem for a premix. Salt has an indefinite shelf life. It will clump when moist, but that’s about it.


Though baking powder (and baking soda) aren’t subject to spoilage, both may eventually fail to rise to the occasion as leavening agents for baked goods. Baking powder consists of baking soda and one or more salts, plus cornstarch to absorb moisture.

Unopened baking powder remains good indefinitely, but once you open a container of baking powder its potency starts to diminish (from moisture in the air). So long as it is kept sealed up in a dry container, it ‘should’ last for quite a long time (indefinite?). It’s the opening and closing and then reopening and closing that allows more and more moisture to be absorbed into it over time to reduce its effectiveness.


When a recipe contains baking powder and baking soda, the baking powder does most of the leavening. The baking soda is added to neutralize the acids in the recipe plus to add tenderness and some leavening.

Baking soda has an indefinite shelf life if stored in a sealed container in a cool dry place.


No problem for a premix. According to the USDA, powdered milk can be stored indefinitely, if dry.


Stored in the absence of oxygen and placed in a cool storage environment, dehydrated powdered eggs generally have a storage life of 5 to 10 years. Once dried eggs are opened, they need to be used within one to two years.


Yeast expires because it’s ‘alive’, a micro-organism (a fungus) that eventually dies. Yeast has a stamped expiration date, but various conditions (where and how yeast is stored) affect it’s shelf life. The shelf life of yeast will be extended if it is kept in the refrigerator, and even longer in the freezer.

An unopened package of instant yeast typically has a shelf life of up to two years (up to 5 years in the freezer?).

When combining yeast in a premix of other dry ingredients, the effective storage life of the premix (which contains yeast) will likely hinge on the yeast itself.


Milled Flour, the most substantial ingredient, has a somewhat short shelf life (because it’s already milled-ground).

Unopened bags of white flour typically stay fresh for up to a year. As the flour ages, and depending on storage conditions, the flour will eventually develop a bad taste and then go rancid (especially wheat flour). Smell the flour. It will taste like it smells. It may even develop creepy crawlies depending on storage.

Having said that, I’ve consumed processed white flour that was several years old without issue (it was stored well).

Note: Wheat (not having been milled yet) may last decades if stored properly (naturally preserved in it’s shell – the bran).

Shelf Life Of Premix

Depending on what’s in your premix, limiting factors include the flour (~ 2 years), powdered eggs (~ 2 years), and yeast (~ 2 years).

Since flour is used in ALL of the recipes for cakes, breads, or cookies, an approximate 2 year shelf life may be the underlying limit for a premix.

Note regarding vacuum-sealed flour:
“It will also store much longer if vacuum-sealed, BUT, it needs to be vacuum-sealed in a jar or a canister where it remains free-flowing, rather than in a FoodSaver bag where it will get packed tightly. There is moisture in flour, and when it’s packed tight in a FoodSaver bag it can develop a musty smell, so the FoodSaver people suggest vacuum-sealing it in a jar or canister.”

Anyone else tried ready-made premix of dry ingredients?
How have you stored them?


  1. I have flour and cornmeal vacuum sealed in jars as suggested.
    Have used both and not noticed any staleness.

    5 years and counting! :-)

  2. I have only recently started adding pre-mixes to our storage, we have not had them stored for more than three years so I can’t comment on their effectiveness. I have had yeast in my freezer for just short of ten years and although still effective I do have to increase the amount called for by 50% in order to get the same results needed for proper leavening.

    1. Peanut, That’s quite a long time — I’m impressed. How are you storing your yeast in the freezer? And how do you access the yeast you need — do you only dip out what you need with every baked item, or do you take the entire container out to use?

      1. It’s stored in a airtight acrylic container. I remove the top and scoop out what I need then reseal and put back in the freezer. I purchased it specifically for the yeast as it holds exactly one pound of yeast. Never had any problems with moisture getting in the container.

  3. I have found the premix Bisquick in the Costco sized box lasts just over a year if left in original container. The pancake mix loses it’s rise after that long on the shelf. I noticed the difference at the end of one box so I went and hunted up a box slightly younger that was still sealed and it had the same problem rising.

  4. Its a good idea to learn how to grow a good sour dough culture so you dont need yeast, its a LOT of work but well worth the results if you bake your own bread, but you need to make it part of your daily ritual or else you lose it, easy enough to re start but still takes time and commitment.

    1. Yes I used to make lots of bread using sour dough, however after discovering that my husband was diabetic we had to drastically cut down on breads and other baked goods. Hence the almost 10 year old yeast. It just didn’t make sense to try and keep an active sour dough culture.

  5. This article is very timely — I recently purchased a half dozen brownie mixes because of the sale price. :-) I never use mixes but thought I’d try one and when we gave it the taste test, I went back and got 6 to store.

    I had thought to jar-store each of these mixes in their original bag. After reading this post, I’m going to vac-seal in canning jars and include the instructions with each jar. I assume this mix has baking powder, as with original from-scratch brownies. I add water and eggs so these should store for 12-18 months without any problems.

    1. I had brownie mixes in my cupboard for 3 years and used one last week without any problems.

  6. premixes are usually a waste of money, and you lose a lot of versatility you have with separated ingredients.

    You can store most ingredients for baking for years.. active dry Yeast for example. most large bakeries dont use any other yeast since decades, works always and dont needs any freezing.

    white flour loses quality after long storying, but its easy to rotate and you can use it stored well also for years.

  7. here might be a good thing for a prepper to know.
    How to Make Your Own Sour Dough Bread Starter…
    ran across these instructions.

    Sourdough Starter
    8 cups freshly ground rye flour
    8 cups cold filtered water
    2 large mixing bowls
    2 Cheesecloth

    Note that making a sourdough starter really requires freshly ground rye flour. If you use store bought, even if organic, it is likely the starter will not take and will get mold on it before it is ready. I know this from experience!

    In addition, you will get your best results from making your sourdough starter with rye flour instead of wheat. Once your sourdough starter is ready, you can of course bake your bread with whatever grain you like. It’s just best to use rye for the starter alone .. you don’t have to make rye bread with it, in other words.

    If you really want to make your sourdough starter with wheat, I would recommend einkorn which is the only unhybridized wheat left on planet Earth and, like rye, is lower in phytic acid and gluten than modern hybrid wheats.
    Note that the total time to make a proper sourdough starter is one week. It doesn’t take much time each day, but you have to give the dough a chance to get “ripe” with lactobacilli.

    Day 1: Mix 2 cups flour with 2 cups of cold water. The mixture will be rather soupy. Cover with a *double* layer of cheesecloth secured by a rubber band. This will allow beneficial wild yeasts and bacteria to get into the culture but will keep critters out.

    If the weather is good, set the bowl outside in the shade if you live in an unpolluted area and you don’t spray any pesticides around your yard. If this is not possible, set the bowl in a warm, open area like an indoor patio.

    Days 2-7: Every day for a total of 7 days, transfer the ripening sourdough starter to a clean bowl and add 1 cup of fresh flour plus 1 cup of cold water or even a bit more to make the mixture soupy. Cover with a fresh cheesecloth and let stand.

    After a few days, you will notice the mixture begin to bubble. It will also smell a bit like wine. The frothy

    Sometimes, despite your best efforts, the sourdough starter fails and gets mold on it before the 7 days is up. – Try Again.

  8. Thank you so much for this blog post! Perfectly answered what I thought would be impossible to find.

  9. I have a cake mix that is over 8 year past Use by date. Still in the box and stored in a tupperware container in our basement. It was forgotten about. Is it ok to use.

    1. It should still be good. The only problem is that it might not rise as much as it should. You may wish to add additional baking powder, otherwise it may be a bit dense once baked.

  10. I’d like to ask what the shelf life would or could be for a homemade premix that incorporates shortening into the mix. No dried eggs powder used, but there is milk powder…

    Any feedback would be really appreciated. Thanks

    1. @Sifulya, Shortening (vegetable shortening) is made from plant oils which are then hydrogenated, and lasts longer than animal oils. Evidently ‘they’ say that unopened you’re okay for about 2 years. Once opened, you’re looking at about 6 months to a year depending…

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