Oven canning flour may seem like an unusual concept, but it can actually help extend the shelf life of this pantry staple. Flour is sensitive to oxygen, light, moisture, and warmth which causes it to go rancid over time. By oven canning flour in sealed jars, you can keep it fresher for longer. In this article, we’ll explore the benefits and proper methods for oven canning flour at home.
What Is Oven Canning?
Oven canning is a way of preserving foods in Mason jars using dry heat. It involves placing filled, capped jars in the oven to sterilize them and create a vacuum seal. This process kills microorganisms and removes oxygen from the jars, preventing spoilage. Foods canned this way can be shelf-stable for over a year when stored properly.
Oven canning works especially well for low-acid foods like flour that cannot be safely water bath canned. The oven provides enough heat to kill bacteria and mold spores without cooking the flour. When done correctly, oven canning makes an airtight seal on the jar lids as they heat and cool.
Benefits of Oven Canning Flour
There are several advantages to oven canning flour:
- Extends shelf life – Properly oven canned flour will stay fresh 3-5 years or longer. Unopened jars may last indefinitely.
- Maintains quality – Oven canning prevents oxygen and moisture from causing flour to go rancid or moldy.
- Saves money – Buying flour in bulk and oven canning it allows you to get a better price per pound.
- Enhances storage – Canning makes flour storage more organized by containing it neatly in quart jars.
- Improves readiness – Having home canned flour makes baking easier. The jars are portable and convenient to use.
- Increases self-sufficiency – Being able to preserve your own pantry basics like flour reduces reliance on stores.
Oven canning gives you control over the quality and freshness of your flour for the long-term.
Choosing Jars and Lids for Canning Flour
To safely oven can flour, you need specialized equipment:
Canning Jars
Use new regular or wide-mouth Mason jars in pint or quart sizes. Do not use old jars or ones with any cracks or defects – these may break during heating. Ball and Kerr are examples of reputable canning jar brands. Clear jars allow you to see the contents inside.
Canning Lids
Always use new, unused flat metal lids and screw bands when oven canning. Old lids or ones that have been through previous canning may not seal properly. Purchase lids specifically designed for home canning.
Oven Thermometer
An oven thermometer is essential for maintaining accurate temperature when oven canning. Do not rely solely on your oven’s built-in thermometer. Place the oven thermometer on the center rack to monitor the true heat level.
Investing in high-quality jars, lids, and a thermometer is necessary for achieving safely sealed jars of flour.
Step-by-Step Guide to Oven Canning Flour
Follow these simple steps for successful results oven canning flour at home:
1. Preheat oven to 225°F
Preheating achieves an even heat level for efficient processing. Bake flour at 225°F, no higher. Temperatures over 250°F can cause excess pressure buildup.
2. Wash jars and lids
Wash Mason jars and lids in hot, soapy water. Rinse thoroughly and inspect for damage. Jars should be spotless for canning.
3. Fill jars
Pour flour directly into clean jars. Fill only up to 1 inch from the jar rim to allow room for expansion during heating. Use a plastic utensil or wooden chopstick to release air pockets. Wipe any spilled flour from the rims with a damp towel.
4. Apply lids and bands
Place a new flat lid on each jar, then screw on a metal band fingertip tight. Do not overtighten bands. Overtightening can prevent air from venting during processing.
5. Load jars in oven
Arrange filled jars upright on a rimmed baking sheet with at least 1-inch space between each jar. Staggering helps heat circulate evenly. Use a sheet with guard rails to prevent tipping.
6. Bake for 1 hour
Bake flour for 60 minutes at your oven’s true 225°F temperature. Start timing when the thermometer stabilizes at 225°F. Do not open the oven during baking.
7. Turn off oven and cool
After baking for 1 full hour, turn off the oven and let the jars cool undisturbed for 24 hours. Do not try to speed cooling with water or fans. Gradual cooling creates an airtight seal.
8. Check seals and remove bands
Press on each lid to ensure it does not flex up and down when the middle is pushed. Remove screw bands. Wash jars and label with contents and date.
9. Store properly
Store oven canned flour in a cool, dark place up to 3-5 years. Check periodically for broken seals, mold, or any signs of spoilage before use. Re-process any unsealed jars within 24 hours.
Follow these oven canning steps precisely each time for successful long-term flour storage. Always use tested canning recipes from trusted sources. Never oven can low-acid foods like flour using unofficial methods due to serious health risks.
Frequently Asked Questions
Many people new to oven canning flour have additional questions. Here are answers to some common FAQs:
Is oven canning flour safe from bacteria?
Yes, oven canning eliminates bacteria when done properly at the right temperature. Flour does not contain enough moisture to support bacterial growth after canning. Just be sure to start with fresh, dry flour.
What temperature should flour be canned at?
Bake flour at exactly 225°F for 1 hour. Temperatures above 250°F risk excess pressure in jars. Too low under 200°F may not kill all bacteria. Use an oven thermometer for accuracy.
Can any flour be oven canned?
All types of flour can be oven canned including white, whole wheat, gluten-free blends, etc. Just avoid expired flour or any with mold, bugs, or rancid smells.
Does oven canning nutrient content of flour?
Oven canning has minimal effect on the nutrient profile of flour. Since it is not cooked, the vitamins and minerals remain intact. The dry heat does not degrade nutrients.
How long does oven canned flour last?
Properly oven canned flour lasts 3-5 years stored in a cool, dark place. Jars stored for over 5 years should be inspected closely before use. Discard any with signs of spoilage.
Can oven canning cause jars to explode?
Overfilling jars or baking at too high of heat can cause flour and steam to expand rapidly and break jars. Follow trusted recipes exactly to prevent explosions.
Oven Canning Flour Recipes
Once you understand the basics, try these delicious recipes for oven canning flavored flour blends at home:
Everyday White Flour
Ingredients:
- 4 cups all-purpose flour
Directions:
- Preheat oven to 225°F.
- Fill a clean quart jar with flour, leaving 1-inch headspace.
- Wipe rim, seal lid, and band.
- Bake for 60 minutes, then cool for 24 hours.
- Check the seal, then store.
Whole Wheat Flour
Ingredients:
- 3 cups whole wheat flour
- 1 cup all-purpose flour
Directions:
- Preheat oven to 225°F.
- Mix flours together in a bowl.
- Fill a clean quart jar with the flour blend, leaving 1-inch headspace.
- Wipe rim, seal lid, and band.
- Bake for 60 minutes, then cool for 24 hours.
- Check the seal, then store.
Italian Herb Flour
Ingredients:
- 4 cups all-purpose flour
- 2 Tbsp dried basil
- 2 Tbsp dried oregano
- 2 Tbsp dried parsley
- 1 Tbsp garlic powder
- 1 Tbsp onion powder
Directions:
- Preheat oven to 225°F.
- Whisk herbs and spices into the flour.
- Fill a clean quart jar with the flour blend, leaving 1-inch headspace.
- Wipe rim, seal lid, and band.
- Bake for 60 minutes, then cool for 24 hours.
- Check the seal, then store.
Feel free to create your own oven canned flour blends! Let your imagination run wild with different herb and spice combinations.
Tips for Successful Oven Canning
Follow these best practices to safely oven can flour with great results:
– Only use trusted recipes from reputable sources like the USDA or Ball Canning.
– Carefully wash and inspect all jars, lids, and bands before each use. Defects can prevent proper sealing.
– Fill jars 1 inch from the top to prevent overflow and explosions from heat and steam expansion.
– Wipe jar rims completely clean before sealing. Flour residue can cause seal failures.
– Bake flour at exactly 225°F for 1 full hour. Use an oven thermometer for precision.
– Let jars cool fully before handling. Gradual cooling creates a vacuum seal.
– Press on cooled lids to check the seal before removing bands. Re-process unsealed jars.
– Label jars with contents and date after canning. Store in a cool, dark place up to 3-5 years.
– Inspect stock routinely for broken seals or any signs of mold, moisture, or bugs.
– Follow all oven canning safety advice to prevent botulism risks. Only can high-acid foods in a water bath canner.
Conclusion
Oven canning is an effective method for safely preserving flour long-term to maintain freshness and quality. Taking the proper precautions allows you to extend the shelf life of flour for a few years while saving money buying in bulk. Canning your own flour means having a from-scratch baking staple on hand anytime.