One gal mentioned that her husband was a firefighter and that leaving a stockpot simmering overnight or while they were out of the house was completely out of the question.
If leaving a stockpot on the stove on low heat, continuously simmering for anywhere from 6-50 hours depending on the types of bone broth is in any way a concern, you have a couple of options. Option number one is to make fish stock. Fish stock is very fast and you can make a quick gallon of it in only 4 hours.  Alternatively, you can make bonito broth which takes only a few minutes.
Option number two is to use the Cumulative Time approach for making stock. Monica Corrado, MA CNC and author of the blog Simply Being Well introduced me to this concept recently when I sat in on one of her amazing cooking classes at the Fourfold Path to Healing Conference in Baltimore.
The Cumulative Time approach for making stock simply means that the required simmering time for a particular type of stock can either be continuous or broken up into sections that equal the total required duration when added together.
The catch is that each time you start to heat the stock again, you must bring it to a boil, skim the foam, and lower to a simmer.  You can’t just bring it to a quick simmer after it’s been off the heat for awhile.
Making Stock: What to Do When the Heat is Turned Off
The great news is that there is no need to move the stockpot in and out of the refrigerator between simmering sessions on the stove. The reason is that it would take a stockpot 4 hours or more at room temperature before any pathogens started to grow.
Anyone who is experienced making stock knows that a stockpot with the lid left on will never get to room temperature for 4 hours even if you leave it on the stove for 12 full hours with the heat off.
If the length of time required to make chicken or beef broth has been intimidating to you in the past, try the Cumulative Time approach! Just be sure to keep a little notebook in the kitchen so that you can log the total amount of time the stock has simmered so that you ensure a quality, gelatin rich broth when you are finished.
Making stock safely couldn’t be easier when using the cumulative time approach!
Sarah, The Healthy Home Economist
We use a crock pot-works great and greatly lessens the risk of a fire.
What a great idea, Dawn. The thing that’s held me back from stock is definitely the time component. I’m not comfortable with an open flame going while we’re asleep or out, nor do I possess the planning & managing chops to keep track of simmering time. So I love the idea of the crock pot.
Can you share what kind you have, what temps you use, when you lower the temp, etc? I’m very new with the crock pot and only know enough to be dangerous – but not effective. ; )
I use my crockpot too. After letting the bones soak with a splash of ACV I turn it on high. Skim if needed once simmering. Later I will turn it to low for the rest of the time.
I definitely love my crockpot for stock making. I have a 6 quart hamilton beach that is about 5 years old. I add all the ingredients and a generous blast of vinegar, cover and cook on high. On high I get a nice simmer, and from beef bones I get stock with so much gelatin you have to gouge it from the jar. For chicken stock I get a much softer gel, but still it normally gels. If it isn’t gelled after 24 hours in the fridge (which happens if I don’t have many or very good quality bones in the pot), I put it back in the crockpot on high, bring it to a simmer and then I crack the lid. I let it cook ’til the volume is reduced by half. By then I normally have a nice gel.
Haha the first thing I thought when reading this was, USE YOUR CROCKPOT!!! Scrolled down to post and you had beaten me to the punch. 🙂 I don’t know if stock would ever get made at my house if not for a crockpot. We’re busy people and are in and out of the house all the time.
Once you’ve brought it to a boil and skimmed the scum, it’s best to turn it down so it is barely burbling. A high simmer for the duration isn’t recommended since it can oxidize the cholesterol, from what I understand. Ideally you want a very slow, almost still, gentle simmer.
I do the same thing. I turn it on high and let it boil for a couple hours then turn it on low for 24-48 depending on how much stock I’m making. It gels great every time!
I’ve been doing this for years now. It’s nice to know that others are too.
I have always let mine simmer on extremely low heat overnight. Now I am wondering if I should be concerned doing that due to a fire hazard? :/
I do both the stove top and the crockpot. Although now with GAPS its both crockpots PLUS the stove top! lol! I do have to check the stove top though as its in a drafty place and has blown out before when someone left the back door open. That made me nervous so I try to use the crock. Is there anything wrong this using a crockpot? I bring it to a boil on the stove and then transfer it to the crock… and when reusing bones do you need to boil it again?
Since I work outside of the home, I am unable to use the stovetop (also have gas stove and worry about gas leak if flame went out) and need to start doing this regularly. I just started making my own broth and am so excited to add it to my family’s regimen. Could you please tell me how long you let your broth cook in the crockpot? I like the idea of boiling it and transferring! I am loving all these tips–and thanks to Sarah for getting this info out there for me!!
I have a gas stove as well and I can’t take that risk. I boil on the stove and then transfer to a crockpot. I wish mine had a temperature setting. That would be awesome!
I usually just boil it on the stove and get out the scum and then transfer it to my crock pot. I had to play around with the temp settings as I have two VERY different crocks and neither are anything fancy! I got it to where its def on the verge or at a low simmering bubble. (not boiling!) And honestly I leave it in the pot for however long it takes me to get back to it! lol! usually overnight. I would consider the timing the same as if you had it on the stove. I think the newer crocks that are all fancy would work even greater… thats why I am bugging my hubby to get me one 😉
This is how I make bone broth. The broth is always wonderful. There’s never too much for freezing though. It’s usually gone within 3 days.
I always make my stock in a crockpot. That way I feel comfortable leaving it going while I’m gone or overnight.
I always use my crockpot. The rolling simmer is always perfect and my stock gels, no problem…even the lower quality chicken that I use sometimes to stay within budget.
Ever whipped up a gelatinous stock in a VitaMix – FROTHY!!!!
If I do have to leave it turned off at any time, I put a lid on it and bring it to a good rolling boil for a couple minutes before I shut it off. This should kill any pathogens that have happened to drift in and the lid keeps others from drifting in.
However, most of the time I just leave it simmering the entire time.
I use my crock pot for bone broth too, I unplug it in the morning when I leave for work. I put a couple cups and a bit of sea salt in a thermos to drink on my drive to work. Then when I get home I plug the crock pot in, bring it to a rolling boil, and then turn it down to a simmer while I’m sleeping. I repeat this each week, with a new batch. I guess I’m more scared to have the crockpot going when I’m not home, than to have it on when I’m sleeping 🙂