My precision cooker is currently being shipped and, while I’m waiting, I’d like to ask you a question.
This is what happens in my SV container after a 18 hours long cook (the longest I used a SV machine):
There are “floating” limescale flakes floating everywhere, it looks like a dirty acquarium covered in slime and the machine absolutely needs descaling after.
I usually fill the pot as high as possible to the MAX level of the stainless skirt and add 0,5L of alcohol vinegar then let the machine go for 1 hour at 60C.
I was wondering if there’s a way to prevent the buildup of limescale by adding something to the water inside the container during the cooking, if that’s possible and doesn’t damage the machine or harms the bags with the food inside.
For example at my local store they sell buckets of powdered citric acid that dissolves in water, are these a solution/good idea?
Use distilled water. End of problem
It appears you have an unusually high degree of water hardness or the APC wasn’t sufficiently rinsed after your unusually weak descaling treatment. Try a straight vinegar dip in a jar next time followed by a water rinse. If you can find 6% cleaning vinegar it works even better and quicker. It can be reused too.
My water supply has 6 grains of hardness and the calcium accumulation is judged minimal requiring descaling after every 25 cooks or so. Frequent cooking at high temperatures will increase the scale buildup.
If you use distilled water it can be reused many times.
My water has never been that hard, that was the first and only time that I witnessed that slimy mess, but usually my cooks last for 2-3 hours on average and definitely not as high as the 74C I set the machine to for cooking pork shoulder for 18 hours.
After a 12 hours cook the water was clean but touching the stainless skirt of the machine (the one in the picture is not an Anova btw but it was clean and basically new) just after I took it out the bath it felt rough and white dust appeared as it dried up.
Never thought of this, but it doesn’t look convenient for me since I don’t cook everyday SV and I can’t leave the container with water laying around until the next cook.
That’s why I was thinking of adding a descaling agent, such as citric acid, to the water every time it’s easier for me (I water the plants and wash the dishes with the used water unless it looks like the picture I posted).
I never tried using this one btw and that’s why I ask before doing something wrong either for my food in the bag or the machine.
If you live in an area with really hard water (and it appears you do), you may want to invest in a water softener for your home. Lots of companies make and sell them. Using soft water will minimize any buildup on your Precision Cooker.
I’ll consider buying one of these thanks.
Just a last question while I am still at it.
You suggested using distilled water and reusing it (how many times can it be used for long 15-20 hour sessions?), that’s what I’m probably going to do next time I’ll make something low and slow, but can it be recycled if I use liquid smoke in the food in the bags?
Maybe it’s a stupid question, but since I don’t really know the answer…the “problem” is that liquid smoke seems to filter through the bags since I can definitely smell it when I open the lid (no smoke drops outside the bag before sealing) and if it does this then I can assume that it could potentially reach the food inside the bags, right?
Right, but it’s use dependant. You can repack distilled water between uses as long as it’s clean, as in smoke free.
I suspect the smoke molecules are small and can slip through the plastic while the fatter water molecules can’t. I’ve noticed coffee aromas penetrating plastic too which is why the better brands pack in metal or Mylar lined packaging.
There’s been considerable discussion here over the years regarding smoke-cook or cook-smoke. Consensus has been that there is less smokiness with the first option although i can go either way depending on the menu item.
Only use distilled water. Its better for your anova
Thank you, then I guess that I’ll use the liquid smoke only for “quick” cooks (max 4 hours below 60C) and use the distilled water multiple times for long cooks so I won’t see that slime again.
A word of caution - pure water (H2O) is highly corrosive!
Basically, water needs to balance itself chemically and it achieves this by either robbing (corroding) or shedding (scale depositing). Since pure water contains nothing dissolved in it, it is negatively balanced; consequently, it will acquire whatever it requires in order to neutrally balance itself - stainless steel is not immune.
To learn more look up the Langelier Saturation Index in your preferred search engine.
@mgoody I love when people throw Science into the equation. Thank you for posting this. I do electroplating (depositing) and electroetching (corroding) and what you said makes perfect sense to me. That’s homeostasis. To the OP. I just clean with citric acid whenever the lime/calcium scale builds up, like I do with my coffee maker and kettle. I’m not sure I’d go so far as to add it to a cook though, even though it’s food grade citric acid.
Thank you for the scientific insight.
Since I noticed that very noticeable limestone build up appears in cooks over 8-10 hours I’d say that I would use the distilled water for these ones and normal water for regular “quick” cooks that on average lasts 2 hours and descale when needed.
I discarded the use of citric acid after and during cooking, I’ll just use vinegar but I still have to figure out if it’s safe to add a bunch of it in the water bath (maybe a glass).
Maybe I can ask the Anova customer support, they supposedly should know if this hurts the machine.
I recently bought the Pro and the manual has a section on descaling. It says to use a 50/50 solution of water and white vinegar in a small pot. Run the temperature up to 140 degrees F and let it run for 30 minutes. Remove and let dry completely.
Distilled water would work but what a PITA. How many gallons would you need to have on hand, anytime you wanted to SV?
Instead or a water softener (which requires a soft water loop already built into your plumbing system), I’d get a whole house filtration system.
Here in Phoenix, AZ, we have hard water.
I’ve had a water softener, and you still get stains from the water.
With a water softener, if you fill your SV tank with water from the kitchen sink, it’s not going to be soft water anyway - by Plumbing Code, kitchen sinks cannot be served with soft water - all other faucets can but not the kitchen sink. Softened water doesn’t taste good, so you don’t want that in the kitchen when you’re filling up coffee makers and tea pots.
In my most recent place, I put in a whole house filtration system - no more bags of salt, and I just change filters every six months, and get nice tasting water, with very few minerals in it, at every faucet in the house.
I’m back because I had an epiphany: what if I use the condensed water discharged from my house air conditioner?
Isn’t this water basically free of limescale and just the same as distilled water?
This would straight solve the problem of storing a big volume of distilled water because everyday I would have enough water for my needs and I can always recycle it for days, if this works of course. At least until the end of the summer.
Also, on long cooks I noticed that the water smells like the food in the bags, as I said with liquid smoke is really noticeable, and this time I cooked a Chuck roll for 24 hours and I could smell it even on the plastic after washing the water tank with dish soap.
If my distilled water is infused with the smell of the food I’m cooking is it still considered clean? Of course the bags were intact, nothing leaked in the water bath.
We have very limey tap water here in central Texas. I just add a dash of double strength vinegar to prevent lime coating the bin and the Anova.
We’ve never considered a water softener, because every relative that has one, has salty-tasting tap water. For drinking and cooking we have a water cooler and spring water delivered once a month.
If you’re using bottled water for drinking and cooking, why would you care how the water tastes out of your tap?
The advantages to soft water:
- no hard water scaling build up in your hot water heater, pipes, kettles, sous-vide or any other water heating appliances
- your soap / detergent is much more effective - you can use less.
My husband prefers to drink tap water.
About 2 ounces of double-strength vinegar in a 12 quart bin works fine .
Many households that have soft water actually run a separate line for a drinking water tap (as there’s health benefits to drinking hard water)