Bone Broth Fasting Rules (Prep Safety Guide)
A safe bone-broth fast starts with careful cooking, fast cooling, and cold storage. Broth contains calories, protein, and often sodium, so it is not a zero-calorie fast. Use clean, suitable cookware, refrigerate broth at 41°F (5°C) or colder, and reheat each serving to 165°F (74°C). Whether fasting is safe for you depends on your health and clinician’s advice.
The best-kept secret is that safe broth fasting depends less on a long simmer than on what happens after cooking. A large pot can cool too slowly, even if it looked and smelled fine. I recommend treating preparation, cooling, storage, and reheating as one connected process.
A broth-only plan also means more than choosing a recipe. You need to know what your broth contains, how your plan defines fasting, and whether fasting is appropriate for your health. The steps below focus on those decisions and on preventing food-safety problems.
Cookware and Ingredient Setup
Choosing the right pot and handling bones safely helps reduce spills, scorching, and contamination. Start with clean tools and a pot that suits your burner. Then keep raw bones and their juices away from foods that will be eaten without further cooking.
Use a stainless-steel or enamel-lined stockpot. Stainless steel is durable and non-reactive for normal broth cooking. Avoid prolonged simmering or storage in unlined aluminum or copper, which may react with food. A thick, multi-ply base can spread heat more evenly, but it cannot prevent every hot spot.
For induction cooking, hold a magnet to the pot’s base. If it sticks firmly, the pot is generally compatible with an induction cooktop. Check the cookware maker’s instructions as well. There is no universal oven rating or safe temperature for every pot, so follow the exact model’s limits.
Before you begin:
- Wash your hands, work surface, and utensils.
- Thaw frozen bones in the refrigerator, not on the counter.
- Use a clean, intact pot that fits the burner and can hold the batch without filling to the rim.
- Keep raw bones and their liquid separate from ready-to-eat foods.
- Check that the pot is approved for your heat source.
Common setup scenarios
| Situation | Safer choice | Why it matters |
|---|---|---|
| You are using an induction cooktop | Check the pot with a magnet and the maker’s guide | Not all cookware works on induction |
| You are using a large batch | Choose a pot with room for water to simmer without spilling | A crowded pot is harder to manage safely |
| You are thawing frozen bones | Thaw them in the refrigerator | This avoids leaving them at room temperature |
| You are deciding where to store broth | Use clean food-safe containers | Cooked broth still needs safe cooling and storage |
These checks do not need to be complicated. They help you start with equipment that is clean, compatible, and easy to control.
Safe Simmering, Cooling, and Reheating
A controlled simmer cooks broth without the hard bubbling of a rolling boil. After cooking, fast cooling matters just as much: the FDA Food Code benchmark is to cool from 135°F to 70°F within two hours, then to 41°F or colder within four more hours. Use a food thermometer to check.
Add bones and fresh water, then heat the pot gradually. Once the broth reaches a simmer, lower the heat to keep it gentle. Skim as needed and do not leave the pot unattended. Cooking time depends on the recipe; a longer simmer does not make slow cooling or poor storage safe.
When the broth is ready, strain it with clean utensils and portion it promptly into shallow containers. Smaller portions cool faster than one deep container. An ice bath can help: set the container in ice water and stir the broth with a clean utensil as it cools.
Use the following cooling targets as a clear safety benchmark:
| Cooling stage | Target | Time limit |
|---|---|---|
| First stage | 135°F to 70°F (57°C to 21°C) | Within 2 hours |
| Second stage | 70°F to 41°F (21°C to 5°C) or colder | Within 4 additional hours |
The clock begins when the broth drops below 135°F. Do not leave it on the counter for hours while you wait for it to cool. Avoid putting a large, hot stockpot directly into a crowded refrigerator; it may cool slowly and can warm nearby food. Portioning the broth first makes cooling easier to manage.
Refrigerate broth at 41°F (5°C) or colder. Keep it for 3–4 days, or freeze it for longer storage. Label containers with the date so you can track how long they have been stored. Thaw frozen broth in the refrigerator or reheat it from frozen, allowing enough time for it to heat evenly.
Reheat only the portion you plan to use. Heat leftovers to 165°F (74°C), checking the temperature with a food thermometer. When reheating soup or sauce, bring it to a boil, then serve promptly. If you are keeping broth hot for service, hold it at 135°F (57°C) or above.
A practical cooling scenario: If you have made a large batch, do not rely on one deep pot to cool in the refrigerator. Divide the broth into shallow containers, use an ice bath if needed, and check the cooling times and temperatures. If you cannot confirm that it cooled safely, discard it. Reboiling is not a reliable way to make mishandled broth safe because some bacterial toxins can persist.
Storage, Cleaning, and Equipment Care
Safe storage depends on time and temperature, not on whether broth smells fresh. Keep containers covered in the refrigerator or freezer, and use clean utensils each time you serve. If you do not know how long broth sat warm or whether it cooled on time, do not taste it to decide if it is safe.
Use broth within 3–4 days when refrigerated at 41°F (5°C) or colder. Freeze portions you will not use within that window. Leave space in containers for expansion if freezing, and label them with the date. Follow your freezer’s instructions for storage and thawing.
After serving, return unused broth to the refrigerator promptly. Do not leave it at room temperature for an extended period. For hot holding, keep the broth at 135°F (57°C) or above; otherwise, cool and refrigerate it using the steps in the previous section.
Wash the pot, strainer, thermometer, and work surfaces after use. Clean utensils help prevent raw-food contamination and reduce the chance of carrying germs between batches. Follow the cookware maker’s cleaning instructions, especially for enamel or coated surfaces. Stop using a pot if it is damaged in a way that affects its safe use, such as a cracked lining.
If the timeline is uncertain: Smell and taste cannot confirm that broth was cooled and stored safely. A later boil cannot reliably correct a long period of unsafe temperature control. Discard broth when you cannot establish its time-and-temperature history.
Serving and Fasting-Plan Considerations
Bone broth contains calories and protein, so drinking it does not count as a zero-calorie fast. The amount varies by recipe and product. Check the label or recipe, and count additions such as oil, vegetables, or meat if your plan requires it.
Fasting plans use the word “fast” in different ways. Some allow broth; others do not. Ask the plan’s clinician or organizer what counts as permitted intake rather than assuming that broth preserves a fast. Broth can also be high in sodium, and it is not a nutritionally complete meal replacement.
If your plan permits broth, reheat only the serving you need to 165°F (74°C). Serve it in a clean bowl, and return any remaining broth to refrigeration promptly. Avoid repeatedly warming and cooling the whole batch; portioning makes it easier to heat only what you will drink.
Check with a clinician before fasting if you are:
- Pregnant or breastfeeding
- Under 18
- Living with an eating disorder
- Managing diabetes, kidney disease, or significant illness
- Taking medication that may be affected by food intake
A clinician can help assess whether fasting is appropriate and whether the broth’s sodium or other ingredients matter for your health. If you feel unwell while fasting, stop and seek medical advice as needed. Safe food handling does not make a fasting plan medically suitable.
Conclusion
A safer broth routine is straightforward: use suitable cookware, simmer with care, portion and cool quickly, refrigerate at 41°F (5°C) or colder, and reheat each serving to 165°F (74°C). Count broth as food, not as a zero-calorie drink. If the cooling history is uncertain, discard it; if fasting may affect your health or medication, ask a clinician first.
FAQs
Does bone broth break a fast?
Bone broth contains calories and protein, so it breaks a zero-calorie fast. Whether it fits a particular plan depends on that plan’s rules and your clinician’s guidance.
How long can bone broth stay in the refrigerator?
Keep broth at 41°F (5°C) or colder and use it within 3–4 days. Freeze it if you need to store it longer.
How quickly should homemade broth cool?
Use the FDA Food Code cooling benchmark: cool from 135°F to 70°F within two hours, then to 41°F or colder within four additional hours. Shallow portions or an ice bath can help.
What temperature should I reheat broth to?
Reheat broth to 165°F (74°C), measured with a food thermometer. When reheating soup or sauce, bring it to a boil, then serve promptly.
Can I cool broth in the stockpot?
A large, deep pot may cool too slowly. Portion broth into shallow containers and use an ice bath if needed, then check that it meets the cooling time and temperature targets.
Can boiling make broth safe after it cooled too slowly?
Not reliably. Some bacterial toxins may persist after reheating, so discard broth if it was mishandled or its cooling history is uncertain.
Can I simmer broth in an aluminum pot?
Avoid prolonged simmering or storing broth in unlined aluminum or copper. Choose stainless steel or enamel-lined cookware and follow the maker’s instructions.
Is bone broth a complete meal replacement during a fast?
No. Bone broth is not nutritionally complete, and it may be high in sodium. Ask a clinician whether a fasting plan is suitable for you and how broth fits your needs.
Who should get medical advice before fasting?
People who are pregnant or breastfeeding, under 18, living with an eating disorder, managing diabetes or kidney disease, seriously ill, or taking medication affected by food should seek medical advice before fasting.
(This article was written by one of our staff writers, Richard K. Ellison. Visit our Meet the Team page.)
