Build a 12 volt sous vide

[owly]

I have a dislike of running inverters. They are inefficient and noisy. I love my sous vide. It's a low energy and very effective method to cook things with unparalleled precision. Meats and veggies are easy to get exactly the way you want. With sous vide, you can't really overcook... at least not easily. Meats that are tough can be cooked literally for days, and continue to tenderize, without passing that ideal medium rare. A low grade tough chuck for example can be cooked for as long as 48 hours at 130F , and will come out as tender as a rib eye, moist, tender, and pink from one side to the other... It needs only a good sear on a hot grill to get that dark surface you get grilling... it takes only minutes as very high heat. Veggies can be sealed in a bag and cooked at a precision temp for exactly the texture you want, with butter and flavorings, etc. If you haven't tried one, you don't know what you are missing.



I just got curious about building my own to run on 12 volt. Ebay offers everything you would need. A tiny 12 volt pump to circulate the water, a precision temp controller with a thermocouple that runs on 12 volt and has an accuracy of 1/10 deg C, a 12 volt heating element. All the parts there to do it, and not expensive. The result would not be the elegant Annova or Chef Steps. It actually would not be difficult to make it fairly streamlined using a tiny 12 volt motor with an impeller like the commercial ones... an interesting and challenging project. Simple in principle, but challenging to achieve anything resembling elegance.



The beauty of this is that you could do your cooking on very low energy while you have surplus solar power. That means saving on battery storage, as well as cooking fuel, while at the same time creating a superb meal that doesn't require you to tend it over a hot stove in the tropics.



The topic of sous vide cooking on board has been covered here before, and on other forums. In a couple of cases the ignorance and fear about the technique dominated the discussion, with people spreading unfounded fear of botulism..... which while the spores are not killed.... they aren't in normal methods either.... the bacteria itself cannot produce toxins. It's killed at a far lower temp than the spores. Nobody's advocating sous vide for preservation of foods.... only cooking. Other folks talked about high energy usage.... which is silly. I use an insulated pot, and cooking temps are very low. It's actually very energy efficient. It's a method used by the best restaurants in the world, and is heavily documented.


H.W.

[john61ct]

also consider passive solar, very low tech

[Simi 60]

Originally Posted by owly

I have a dislike of running inverters. They are inefficient and noisy. .

That's one persons opinion.

We run ours 24/7 for over two years.
Wouldn't be without it and never hear it.

Oh, and I to like sous vide cooking.

[owly]

Originally Posted by john61ct

also consider passive solar, very low tech

I've thought about that... Problem is collecting solar heat and controlling the temp... two separate operations. The complexity of maintaining a precise temp from solar is not to be under estimated. I haven't figured an elegant way to do that.


H.W.

[john61ct]

Are you sure **that** much precision is critical?

A thermostat pushing a little linear actuator, cracking a lid?

[thinwater]

Why not a 12v crock pot and swap the thermostat? In fact, some hold at 150F, which should be OK for the non-purist (won't be pink). But swapping the thermostat is easy.

[owly]

Originally Posted by Simi 60

That's one persons opinion.

We run ours 24/7 for over two years.
Wouldn't be without it and never hear it.

Oh, and I to like sous vide cooking.

It is more than "one person's opinion". Inverters often operate as low as 75% efficiency. I prefer not to have a dual wiring system with 12 volt and 120 volt, or to be dependent on sensitive electronic equipment merely for the convenience of being able to run shore type appliances.... It is however "the easy way". I'm not sure weather my Annova would like MSW power, or if it would require far more expensive PSW to be happy. What sort of inverter are you using?
I'm preparing to build, and my intention is not to have any dedicated AC circuits if possible. The more systems you have, the more maintenance. The last thing I want is to be sitting at Noumea or Port Moresby waiting for parts, and dealing with import export issues.... I like simplicity!!
A lot of things that make sense stateside are not viable in the remote parts of the world. Imagine being stuck in Punta Arenas for a few months awaiting parts.....



H.W.

[owly]

Originally Posted by thinwater

Why not a 12v crock pot and swap the thermostat? In fact, some hold at 150F, which should be OK for the non-purist (won't be pink). But swapping the thermostat is easy.

Good thought

[Thalas]

Originally Posted by thinwater

Why not a 12v crock pot and swap the thermostat? In fact, some hold at 150F, which should be OK for the non-purist (won't be pink). But swapping the thermostat is easy.

Crock pots are great, but the results always tend towards homogenizing the individual flavors. That’s not always bad, but sous vide is a brilliant idea on a boat. Individual flavors, cooked to perfection, and best of all, should an emergency arise (as is wont to happen on a boat), you have all the time in the world to address it and then come back to your meal.

[dfelsent]

I really like this idea. Sous vide can be super energy efficient, especially with an insulated container. Baggies can be used and no vacuum sealer needed.
Cook and hold. All in one.
You are reminding me that a neighbor gave me some frozen kodiak moose. Sous vide soon.

[CarlF]

My Victron Multi efficiency is over 93%. Most large amperage 12 volt loads lose more than 7% due to wire resistance. You could avoid this by using very large wire gauge or a very small heating element but either would be inconvenient.

Of course, if you don't already have a good inverter it would be silly to spend the money just to run a sous vide.

[thinwater]

I assure you, having 120V available will be simpler than trying to work out all 12V solutions. Really. I've never had an inverter I could really hear.


In general, 12V appliances are more expensive and less efficient, returning some of that inverter loss. A much larger market.



Yes, you want PSW.

[44'cruisingcat]

Originally Posted by owly

It is more than "one person's opinion". Inverters often operate as low as 75% efficiency. I prefer not to have a dual wiring system with 12 volt and 120 volt, or to be dependent on sensitive electronic equipment merely for the convenience of being able to run shore type appliances.... It is however "the easy way". I'm not sure weather my Annova would like MSW power, or if it would require far more expensive PSW to be happy. What sort of inverter are you using?
I'm preparing to build, and my intention is not to have any dedicated AC circuits if possible. The more systems you have, the more maintenance. The last thing I want is to be sitting at Noumea or Port Moresby waiting for parts, and dealing with import export issues.... I like simplicity!!
A lot of things that make sense stateside are not viable in the remote parts of the world. Imagine being stuck in Punta Arenas for a few months awaiting parts.....



H.W.

As long as you're not looking for huge power capabilities you can get PSW inverters for very reasonable prices. Cheap enough that you could easily carry a spare.

We have a 1500W and a 1200W backup to run the fridge and freezer. Efficiency better than 90%. Silent, unless loads exceed around 500W, at which point a fairly quiet fan kicks in.

[GordMay]

... Inverters often operate as low as 75% efficiency...

That would be a very low-quality inverter, and/or improperly sized to it’s load.

Quality sine wave inverters generally have Peak* efficiency on the order of 95% to 98%, and CEC Weighted* efficiency between 94% and 97%.

* Peak efficiency indicates the performance of the inverter at the optimal power output (ideally sized to it’s load). It shows the maximum point for a particular inverter, and can be used as a criterion of its quality.
- European efficiency is the weighted number taking into account how often the inverter will operate at different power outputs. It is sometimes more useful than peak efficiency as it shows how the inverter performs at different output levels, with varying loads, during a day.
* California Energy Commission (CEC) efficiency is also a weighed efficiency, similar to the European efficiency, but it uses different assumptions on weighing factors.

[owly]

Originally Posted by Thalas

Crock pots are great, but the results always tend towards homogenizing the individual flavors. That’s not always bad, but sous vide is a brilliant idea on a boat. Individual flavors, cooked to perfection, and best of all, should an emergency arise (as is wont to happen on a boat), you have all the time in the world to address it and then come back to your meal.

I think you are misunderstanding what he was suggesting. The crockpot would only hold and heat the water for cooking sous vide.... it's the heating element, and container, nothing more.. It would require circulation and a better temp controller to do the job right.


H.W.