Sous Vide while off grid

(Susan) #1

So I’ve gone down the sous vide rabbit hole and ordered one. I’ll make it work. We live in a really rural area on the Big Island of Hawaii and rely on solar for electricity and propane for cooking and hot water. Can anyone confirm if the following ideas will work?

  • Heat up the water on the propane stove to start with to the required temp or a degree or two higher so it’s the right temp after the colder food goes in.
  • Turn the propane back on low for 5 minutes every so often.
  • Insulate the pot in between. My electric system can handle the water pump no problem and some heating, but not hours and hours. I’m thinking I would put plastic wrap over the top and a towel around the pot.
  • I’ll have to choose smaller cuts that take four hours or less and cook on sunny days (no a problem here.)
  • Would it be possible to cook something tougher for 10 hours one day and then 10 hours the next if I need really long cooking times?

One question is when should I put the sous vide into the pot? After I’ve heated the water? I have an electronic thermometer that we got for roasting meat that should work for this too.

Any recommendations?? Thanks!!

#2

you ordered one. Doesn’t what you ordered, a machine, do it all for you? All you do is put water in it, push a button and you walk away?

what did you order? I am not sure why you need all these other steps? All you should need is electricity.

Not sure what I am missing here, sorry :slight_smile:

edited to say…oh wait, am I right in thinking you ordered that stick machine thing?

I am thinking that bigger machine which is all in one.

(Doug) #3

Hey Susan. :slightly_smiling_face: Off the grid in Hawaii - I’d love to hear more about this; sounds fascinating (and certainly, at times, challenging).

I put the food in right away - everything has to heat up anyway, and I figure the sooner the better. ‘Cold’ or room temperature food will usually chill the heated water down more than a degree or two. And until the center of the food gets up to the desired temperature, heat will be being absorbed from the water.

Periodic heating is a good question. Once everything is up to temperature, I’d insulate the heck out of it. Definitely want to keep the pot sealed - a lid or plastic wrap, and I’d also put towels, etc. on top as well as around the sides. More insulation is better than less. If the propane can be turned down very low, that would help.

If you overshoot on the high side when the heat is on, then at least the outside of the food will be more cooked. I would think this has to be acceptable to some degree (no pun intended) - taking the insulation off, turning heat on, waiting, then turning it off and reapplying the insulation - this is some work, and wider temperature swings, if acceptable, means fewer cycles of doing it all.

Some experimentation is needed. A 90° day and 130° sous vide means substantially slower cooling than 80° and 150°, for example. Personally, with a hunk of beef in there, I’d be fine with 6 or 7 degrees above the chosen temperature, and then turning heat back on at 6 or 7 below it. Depending on the insulation and ambient conditions, a temperature swing of 12-14 degrees ought to give decently long intervals between heating it up again - my opinion. You’ll have to see what works best for you. If the food turns out fine, perhaps the next time you can increase the temperature swing.

Tough stuff and 10 hours one day and then the next - is the food going to be refrigerated overnight? If spoiling/bacteria growth is ruled out then I see no problem with it. Some people like beef pretty rare, and if the temperature isn’t getting to ~130°F (54°C) then there is potential danger. This also applies when cooking - you don’t want stuff below 130° for hours at a time, while swinging from 125 to 135 and back (for example) should be no problem.

(Susan) #4

@Fangs Because I rely on solar power and batteries for electricity, I have a limited amount of electricity and can’t run any electric heating element for long periods of time without draining my battery excessively. We even use hot water bottles instead of heating pads! Before coming here, I cooked almost everything in a toaster oven. No longer. No hair dryer either. Lights, fans, recharging the lap top and that sort of thing (my electric piano) don’t take up nearly as much electricity.

(Susan) #5

@OldDoug Thanks for the thoughtful response. I’ve decided that a pot wrapped in towels in the larger cooler with plastic wrap on top (so the sous vide can stick up) should be sufficient. Just so I don’t cook when it’s dark out, the battery shouldn’t be used up too much as the heater turns on and off. As you said, some experimentation will be needed watching the voltage on the battery carefully. We use this method of insulation for bone broth except we don’t need the plastic wrap because we could use the pot lid. Putting the broth back on the stove to come to a boil about every 6-10 hours works well, though I never thought to put the thermometer in and check the heat loss.

I’ve done a lot more reading since I originally posted and found Kenji’s cook-your-meat-in-a-beer-cooler-the-worlds-best-sous-vide-hack that gives me hope that everything will work well, even if it’s not quite as precise as it would otherwise be. I don’t think I’ll need to tolerate large temperature swings to the degree you mention (pun intended.)

130° should probably be my minimum temp for longer term projects because of the chance of bacteria.

Being off grid, we have two top loaded freezers. One is on maximum during daylight and the other on a timer with 15 minute intervals. On minimum for 15 minutes and off for an hour during daylight works well as our refrigerator. Last time I went to Costco (a 3 hour drive one way), I noticed they now have the top loaded freezers with the ability to cool to refrigerator temps too. The timer would just need to turn it off at night like we do with our freezer now.
We went ahead and paid huge bucks for a large lithium battery (car battery sized). It stores a LOT more than the previous ‘normal’ solar batteries and made life more care free. I can even microwave for a few minutes at night without draining the battery noticeably. (Small 700 Watts) We use an on demand propane water heater and cook (oven, stove, BBQ) with propane. I still can’t use a hair dryer for even a few minutes, but that’s not the huge deal it would be in the northern US.

(Bob M) #6

You can also get a plastic cooler and cut a hole in it large enough to hold the sous vide machine. This will limit heat and water loss.

I’ve done this and use it for large hunks of meat for 24 hours or greater.

It helps to have a hole saw.

(Susan) #7

Yep, I saw a picture of that somewhere after putting my first post up. We’ve got the hole saw. When I get to wanting much longer cook times, I’ll probably move to that over the towel insulated stew pot. It’s going to take 10 days for the package to arrive out here in the middle of the best place in the world, so I’m rather frustrated. Time to practice my patience. Thanks for the tip!!!

(Todd Allen) #8

If you preheat the water the stick heater will only cycle on to maintain the temperature. The better you insulate the less power it will take to run. Get a device that can track power usage on an outlet and you can test your setup for an hour or two without the meat and find out how many watts you are averaging to see if you can get it below your power budget. You might have to use a smaller cooking vessel and add more layers of insulation but it should be possible to get the total energy needed quite low.

(Doug) #9

Sounds good, Susan, and a lot easier than unwrapping it all and turning the propane on. Agreed that just maintaining the temperature (especially if you insulate as well as you can) shouldn’t be a big deal. The water has substantial thermal mass, and getting it up to temperature is the big thing.

(Susan) #10

Thanks @brownfat and @OldDoug You give me hope this will really work and chicken will return to being juicy and not stringy, while steak stops being a crap shoot. Now I just have to wait for the thing to arrive!

(Susan) #11

Another question. If you cook something (sous vide, of course), and then freeze it in it’s vacuum bag, how long do you heat it up in hot(ish) water (say, 130 F) before searing and eating it?

(Bob M) #12

Good question. I’ve never done that.

I always go the other way, buy meat on sale, freeze it in bags, then sous vide it.

(Susan) #13

I just figured I can sous vide multiple chicken pieces at a time for not much more energy than 1 or 2, since the bulk of the energy will be in heating things up initially for which I will use propane. My husband thinks freezing things a second time will degrade the quality, but so many of you freeze your meat and still rave about the taste with sous vide.

(Bob M) #14

So, the meat you get there has already been frozen? Then, it’s thawed, and you get that?

If you’re sous vide-ing birds, most recipes use two different temperatures for the breast and the legs, so it would be nice to cut the bird into parts.

But I see your issue: you’d get something previously frozen, sous vide it, then refreeze it, then sous vide it again to bring it to the proper temperature. I guess the easiest thing to do is try the double freezing and then reheating compared to a bird just cooked (if that’s possible).

(Susan) #15

@ctviggen We usually buy large boxes of frozen chicken parts or a pork butt (shoulder) at our local (1 hour away) version of Costco called Cost-U-Less. They sell some Kirkland brand items, so have some agreement with Costco which is 3 hours away. It’s a Big Island.

The chicken parts are all stuck together. I think it’s 5 lbs. So to separate them, we’d have to at least partially thaw them. We could then bag and refreeze them. The pork butt I was planning on cutting as much as I could into 1-1.5 inch thick ‘steaks’ and then a bag of everything that couldn’t be cut that way in stir fry size chunks. I’d clearly have to completely thaw the pork before cutting.

We both retired years earlier than we ‘should’ have and bought the land here for $15,000 and my husband built the house (with friends we paid.) We occasionally buy fresh steak as an expensive treat, but mostly need to be frugal. Our carefree lives wouldn’t be possible without ObamaCare. One bonus of the area is we regularly get fresh Ahi (Tuna, but don’t think of the canned stuff), Sword Fish, Mahi Mahi etc. that we buy from the roadside. 2 lb. steaks. Since it can be eaten raw, we won’t need the sous vide. We just sear it as hot as possible for 1-2 minutes on each side. As we say in Hawaii ‘Broke da mouth!’

I originally thought that cooking larger amounts once in the sous vide would save on time and energy, but I’m not sure it will if I have to sous vide it all over again for a long time. Perhaps I should just plan on cooking things up most days from raw. That still doesn’t solve the problem of the large portions of the thawed meat. I’ll have to remind my husband that we’re usually put part of the roasted pork butt back in the freezer to keep it from going bad while we eat pork or chicken 2mad for days. (I’m 2mad. He’s not diabetic, very fit and is still 3mad, but mourns the decades he saved bacon for special treats and avoided steak and butter.) I don’t see any way around freezing things twice - either initially and after separating things into individual bags OR initially and after sous videing them. Any idea if there’s a difference between the two taste wise? I’m still wondering how long you have to sous vide something that’s been frozen after the initial cooking. A number of people have mentioned doing that but because they don’t have to worry about amounts of electricity used late in the day, never were specific about it. Again, thanks for working this through with me.

(Todd Allen) #16

I have never refrozen meat after cooking it sous vide. My set up handles two 1 quart bags at a time which is only about 4 lbs of meat. I have reusable silicone cooking bags and I store leftovers in the cooking bag in the fridge for a day or two and typically eat them cold. If I did refreeze I’d probably just put it into the fridge to thaw and then eat. If you want it warmer you could rewarm by any method of your choice but there would be no need to sous vide again as it would already be cooked.

(Bob M) #17

Those are all tough questions. And I really don’t have any answers.

I know that if I take out a roast, it can be anywhere between less than 3 to 6 pounds. I leave that in all day (from frozen), as I assume it’s going to take at least 1-2 hours to defrost and get the middle of the roast to temperature. However, I’ve never actually tested it. So, I’m looking at 6-8 hours of sous vide.

Supposedly, they don’t take much power once up to temp. Found this:

If you’re using a cooler, only 83 watts for 24 hours of cooking.

(Susan) #18

@ctviggen
WOW. This link is perfect! Thanks so much for persisting with me. It will take much less electricity than I thought and it looks like I can do much longer cooking times than I had anticipated. It’s clearly that the temps are so low that the heating element doesn’t get turned on for very long at a time.

I finally tested the temp of my soup last night to get a feel for what 130 to 150 degrees might be and it’s a lot lower than I thought. With insulation, I can probably even go overnight if I want. You’ve been a very big help. Now if the postal service could just go a little faster to my very out of the way location!

(Todd Allen) #19

I just cooked a 4lb chuck roast started slightly frozen at 133F for 24 hours, ambient temperature roughly 75F. It took 1.88kwh, 1.02 for the first 12 hours. So it took roughly 72 watts on average to sustain cooking once up to temperature. I’m cooking in a small cooler wrapped in an old worn out winter parka.

(Susan) #20

@brownfat
Thanks for checking that out for me. I’m feeling a lot better about my upcoming experiments. Can’t wait for it to arrive.