How Do You Make Potato Juice

[theLaw]

Update: I emailed Peat about the potato juice preparation, and he said that the juice can be cooked right after juicing as opposed to waiting for the extra starch to settle.

He specifically said that the cooked sediments "aren’t harmful", so the juice preparation above is incorrect as it removes valuable "egg-like" solids containing valuable keto-acids.

Personally, I still let it settle before cooking just to be safe, but I assume that small amount of starch after being cooked is pretty harmless. The quality of your juicer also probably plays a role in how much starch is left.

 

[Ella]

@theLaw, why does the juice in the jar look black?
I thinly slice my potatoes. I only use the yellow flesh ones which produce a liquid similar to the consistency of of eggwhite. Is this what you mean by the "egg-like" solids containing valuable keto-acids?
I don't even bother with white flesh potatoes and no longer grow them.

 

[theLaw]

@theLaw, why does the juice in the jar look black?
I thinly slice my potatoes. I only use the yellow flesh ones which produce a liquid similar to the consistency of of eggwhite. Is this what you mean by the "egg-like" solids containing valuable keto-acids?
I don't even bother with white flesh potatoes and no longer grow them.

The juice is just dark brown without the clumps of keto-acids (mostly water).

Why would the slicing make a difference? Are you juicing them?

 

[Ella]

@theLaw, so the brown colour is due to oxidation of the raw juice. Makes sense. I avoid potatoes browning by cooking the potato first and extracting the ketoacids into the boiling water. A big assumption on my behalf. Anyway tastes good.

I thinly slice to increase the surface area. My mother hates this because she says I waste the potatoes as they disintigrate into the water. She doesn't understand that this is precisely the aim. She has finally learnt to not throw the water down the sink.

I do it this way for two reasons. 1) As mentioned, to increase surface area 2) Water is extremely expensive where I live and I don't like to waste precious water to wash unnecessary utensils in the kitchen. The less equipment the better for me. If I can do it with a knife, I'm happy. I don't even use a chopping board. Just knife and hands, very fast, straight into the pot and it's done in no time. If my potatoes, I don't peel them and no need to scrub and a bit of dirt does not worry me, because its my soil. I would not do this with unknown potatoes, even if they are organic.

I boil them for an hour. So I am hoping that my method of extracting is comparable to juicing the raw potatoes and then cooking. I assume the eggwhite film that forms in the water is due to the amount of ketoacids extracted. There is no sign of this film when using starchy white potatoes. The yellower the flesh, the thicker the film. The yellower the flesh, the more protein.

It would be good to know whether juicing is really necessary to break up the sub-cellular structures to release the keto acids or whether boiling in water is adequate to inactivate the enzymes that would destroy the keto-acids and more important which keto-acids are being extracted and does it matter. IDK.

I am hoping my method is good enough as I would be less inclined to blend my potatoes.

I would appreciate further thoughts. I am investing in potatoes big time as my source of protein. Peat says it is the perfect food as it has zero fat. I don't have digestive issues and it has been wonderful for weight lose and excellent for replenishing minerals and electrolytes.

I tried drinking the raw potato juice and it was horrid.

 

[theLaw]

@Ella

I think that the juicing is just a more efficient way of making the juice as you still have to strain the well-cooked potatoes, but it could probably be done either way. Haidut mentions it here: Potato Protein Soup Cooking Rules

Ray specifically mentions a juicer in his email, but he also states "I used a centrifugal juicer", so not sure if that means that there are other options.

Not sure what effect the boiling would have on the skins, but personally I would remove them.

If I try the yellow potatoes, I'll let you know how it goes. Cheers!

 

[golder]

Would anyone be kind enough to help me out. Obviously this is a very time intensive process, and I want to try to incorporate this infrequently as my digestion is gradually getting better. I was looking for a ready made solution and found this. Would this suffice? Pros/cons? If anyone could chime in absolutely anything that would be fantastic, thanks guys.

https://www.amazon.co.uk/Biotta-Org...8&qid=1540056262&sr=8-1&keywords=potato+juice

 

[aquaman]

The juice is just dark brown without the clumps of keto-acids (mostly water).

Why would the slicing make a difference? Are you juicing them?

No it’s not, at least not for me.

The juice for me only goes black when you leave it to sit for too long, ie it oxidises. I only drain mine for 10 mins, 95% of the starch settles out and I cook the rest. Don’t mind a few grains in it.

After cooking, mine stays light yellow for days.

 

[Light]

From : https://www.tandfonline.com/doi/pdf/10.1080/10942912.2016.1230873

"Potato fruit juice (PFJ) is an aqueous by-product of the potato starch industry. PFJ contains most of the tuber protein released after grinding of potato tubers in a rasping machine. One thousand kilograms of potatoes release 5–12 m^3 of PFJ . PFJ contains 2–5% dry matter, of which one third is protein, peptides, and amino acids/amines"

There seem to me that it must be a mistake where they claim that a thousand kilos of potato make 5-12 thousand liters of liquid, but the same data is quoted again and again, so maybe i'm missing something.

The good news here is that most of the protein from the potato is extracted in the juice, including when juicing with a home juicer acording to one example.

So overall, about 2% of the raw juice is protein, or about 20g-25g in a liter of raw juice.
In another thread :Potato Protein Soup Cooking Rules @Stilgar says:
"I get close to 1 1/2 to 2 litres of juice from 5kg of potatoes (pre cooking)."

So 5Kg of potatoes would make maybe 50g protein in the juice. Or about 10g protein for 1Kg potatoes.
That's about half of the total protein in the potatoes acording to cronometer.
That's really not that much, but for good quality protein with almost no fat it might be worth it.

I would really like to know how some people got these numbers:

Just be careful because that 13 ounces = est. 150-300G of protein.

assuming the pre-juiced to juiced potatoes will always yield a 1lb:30-50g protein ratio

I wish they were right, but I don't see how.

*** What if you juiced the potato after you cooked it? Is there any reason to think you might get more of the protein that way?

 

[Mossy]

From : https://www.tandfonline.com/doi/pdf/10.1080/10942912.2016.1230873

"Potato fruit juice (PFJ) is an aqueous by-product of the potato starch industry. PFJ contains most of the tuber protein released after grinding of potato tubers in a rasping machine. One thousand kilograms of potatoes release 5–12 m^3 of PFJ . PFJ contains 2–5% dry matter, of which one third is protein, peptides, and amino acids/amines"

There seem to me that it must be a mistake where they claim that a thousand kilos of potato make 5-12 thousand liters of liquid, but the same data is quoted again and again, so maybe i'm missing something.

The good news here is that most of the protein from the potato is extracted in the juice, including when juicing with a home juicer acording to one example.

So overall, about 2% of the raw juice is protein, or about 20g-25g in a liter of raw juice.
In another thread :Potato Protein Soup Cooking Rules @Stilgar says:
"I get close to 1 1/2 to 2 litres of juice from 5kg of potatoes (pre cooking)."

So 5Kg of potatoes would make maybe 50g protein in the juice. Or about 10g protein for 1Kg potatoes.
That's about half of the total protein in the potatoes acording to cronometer.
That's really not that much, but for good quality protein with almost no fat it might be worth it.

I would really like to know how some people got these numbers:





I wish they were right, but I don't see how.

*** What if you juiced the potato after you cooked it? Is there any reason to think you might get more of the protein that way?

Maybe during cooking evaporation of moisture would happen, which would yield less liquid. Or, the protein would remain within/bind to the solid, not extracting within the liquid/juice. But, these are just guesses, which more scientific minds could correct or confirm.

 

[Light]

Found another study: https://brage.bibsys.no/xmlui/bitstream/handle/11250/134400/Strætkvern.pdf?sequence=1
According to them 8Kg potatoes make about 4.8L potato juice, so around 60% of the potatoes' weight is juice.
And they got around 12.5g of protein/liter of potato juice, which comes down to only 7.5g of protein for every 1Kg potatoes, or less than 1%.

 

[Mossy]

Found another study: https://brage.bibsys.no/xmlui/bitstream/handle/11250/134400/Strætkvern.pdf?sequence=1
According to them 8Kg potatoes make about 4.8L potato juice, so around 60% of the potatoes' weight is juice.
And they got around 12.5g of protein/liter of potato juice, which comes down to only 7.5g of protein for every 1Kg potatoes, or less than 1%.

If I understand correctly, the measurement of protein for the potato juice is in relation to keto-acids, which would not be a 1:1 measurement of protein, as protein is normally measured--hence, the reason for the greater protein being yielded for this juice. At least, this is my limited understanding/interpretation.

 

[Light]

Yeah, I looked into that : https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1199774/pdf/biochemj00851-0177.pdf
Even if all the keto acids in the potatoes would convert into amino acids (which doesn't seem to be the case),
according to this study, 1Kg of potatoes has around 0.006g of keto acids.
It's really really negligible...
(I write this with some pain, as I have just had the delivery guy drop off my new juicer... and I have 10Kg of organic potatoes arriving this evening )

 

[tara]

*** What if you juiced the potato after you cooked it? Is there any reason to think you might get more of the protein that way?

I doubt it - I imagine the starch gelatinises by absorbing the liquid? Ever tried squeezing a cooked spud? In my experience you just get mashed spud.
I share your skepticism about some of the maths you quote.

 

[michael94]

Yeah, I looked into that : https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1199774/pdf/biochemj00851-0177.pdf
Even if all the keto acids in the potatoes would convert into amino acids (which doesn't seem to be the case),
according to this study, 1Kg of potatoes has around 0.006g of keto acids.
It's really really negligible...
(I write this with some pain, as I have just had the delivery guy drop off my new juicer... and I have 10Kg of organic potatoes arriving this evening )

dont count your broken eggs before they break...

 

[Ashoka]

I tried making this today, and it’s the second time I’ve tried altogether. The first time I stupidly made the “scramble” lol. Oh dear. This time I guess I didn’t allow enough time for all of the starch to settle, because towards the end a small layer of starch built up and burnt the pan. I’m guessing it ruined the taste of the finished product quite a bit.

I’m a bit confused about this “egg-like solid” business. Are we saying that just by adding enough water to the potato juice right after juicing, it’s not going to turn into a starchy paste? (I’m clearly no chef.) It’s kind of rough to experiment with this because it takes a while and you go through a lot of potatoes.

I attached a photo of what I ended up with. It tastes a little burnt, not too great but not awful. I’m guessing it would still be okay to have?

 

[Mossy]

I tried making this today, and it’s the second time I’ve tried altogether. The first time I stupidly made the “scramble” lol. Oh dear. This time I guess I didn’t allow enough time for all of the starch to settle, because towards the end a small layer of starch built up and burnt the pan. I’m guessing it ruined the taste of the finished product quite a bit.

I’m a bit confused about this “egg-like solid” business. Are we saying that just by adding enough water to the potato juice right after juicing, it’s not going to turn into a starchy paste? (I’m clearly no chef.) It’s kind of rough to experiment with this because it takes a while and you go through a lot of potatoes.

I attached a photo of what I ended up with. It tastes a little burnt, not too great but not awful. I’m guessing it would still be okay to have?

If I understand your question, you will need to cook the potato juice to attempt to get a scrambled egg like result—though, I can say, I was not able to do it. Also, you do not need to add water to the juice—unless, of course, you should want to increase the volume for some reason. @theLaw has pretty good instructions on one of these threads. If it’s not this one, maybe it’s this one.

 

[Light]

I tried making this today, and it’s the second time I’ve tried altogether. The first time I stupidly made the “scramble” lol. Oh dear. This time I guess I didn’t allow enough time for all of the starch to settle, because towards the end a small layer of starch built up and burnt the pan. I’m guessing it ruined the taste of the finished product quite a bit.

I’m a bit confused about this “egg-like solid” business. Are we saying that just by adding enough water to the potato juice right after juicing, it’s not going to turn into a starchy paste? (I’m clearly no chef.) It’s kind of rough to experiment with this because it takes a while and you go through a lot of potatoes.

I attached a photo of what I ended up with. It tastes a little burnt, not too great but not awful. I’m guessing it would still be okay to have?

I admit I Gave up the juicing idea, you lose most of the protein and nobody's quite sure how to make the liquid work.

Someone around here said they use the liquid like you would use stock - adding it to long-cooking mushrooms, and that sounds like the best option to me.

For myself - I just made mashed potato with butter, milk and parmesan - it tastes goos and has lots of protein from both the potatoes and dairy.

Good luck with your experiments, please post any progress, as many people find it hard to get right and good advice is very welcomed :)

 

[Ashoka]

If I understand your question, you will need to cook the potato juice to attempt to get a scrambled egg like result—though, I can say, I was not able to do it. Also, you do not need to add water to the juice—unless, of course, you should want to increase the volume for some reason. @theLaw has pretty good instructions on one of these threads. If it’s not this one, maybe it’s this one.

I admit I Gave up the juicing idea, you lose most of the protein and nobody's quite sure how to make the liquid work.

Someone around here said they use the liquid like you would use stock - adding it to long-cooking mushrooms, and that sounds like the best option to me.

For myself - I just made mashed potato with butter, milk and parmesan - it tastes goos and has lots of protein from both the potatoes and dairy.

Good luck with your experiments, please post any progress, as many people find it hard to get right and good advice is very welcomed :)

Mossy, that is exactly what will happen if you don’t let the starch settle after juicing. You get the rather bizarre “scramble”. I did that the first time. This time I let the starch settle but probably not long enough (maybe over half an hour), removed the juice, and cooked that for an hour. But the starch apparently wasn’t done setting, so well into cooking, another layer gathered in the pan and started burning.

The problem is whatever I created tasted quite awful ha. Burning it slightly doesn’t help, I’m sure. But some people seem to be saying that this is not in fact awful and can be made to sip. And my end product doesn’t quite look the same as other images, probably because I didn’t filter it enough and didn’t use a fine enough sieve. I didn’t want to lose these valuable egg-like solids lol. But next time I do it I’m really going to make sure I really end up with just the juice. Because I’m guessing that’s the only thing that will taste reasonable enough to sip (perhaps with some salt added).

Edit: Also, does the juice have to be consumed immediately? A lot of sources seem to say that, but they’re talking about raw potato juice.

 

[Mossy]

Mossy, that is exactly what will happen if you don’t let the starch settle after juicing. You get the rather bizarre “scramble”. I did that the first time. This time I let the starch settle but probably not long enough (maybe over half an hour), removed the juice, and cooked that for an hour. But the starch apparently wasn’t done setting, so well into cooking, another layer gathered in the pan and started burning.

The problem is whatever I created tasted quite awful ha. Burning it slightly doesn’t help, I’m sure. But some people seem to be saying that this is not in fact awful and can be made to sip. And my end product doesn’t quite look the same as other images, probably because I didn’t filter it enough and didn’t use a fine enough sieve. I didn’t want to lose these valuable egg-like solids lol. But next time I do it I’m really going to make sure I really end up with just the juice. Because I’m guessing that’s the only thing that will taste reasonable enough to sip (perhaps with some salt added).

Edit: Also, does the juice have to be consumed immediately? A lot of sources seem to say that, but they’re talking about raw potato juice.

I do let the startch settle and poor the juice off, leaving the startch to be discarded. I can get a consistent result every time, that looks like this.

The juice does not taste that hot, but you can dress it up, with mushrooms, eggs, etc., if you have time. Otherwise, you can just shoot a little bit with something else. Assuming it is as concentrated as it’s being talked about, you don’t need much at a time. My 2 cents.

P.S. I’m adding an photo of how I’ve eaten it.

 

[TripleOG]

Made my first batch with 2lb of potatoes. Was surprised how much starch settles at the bottom. I was left with about 8oz of juice. Put it in small pot and started cooking. I immediately understood what Peat meant when he described the coagulating fluid as "egg-like." The fluid became more clear as the coagulation went on. I see how this can mimic eggs if cooking in a pan and letting the water evaporate out.

The taste wasn't horrible, but definitely gonna take some getting used to.. It reminds me of cooked mushrooms with a strong earthy kick. A salty, metallic taste. Is that the high amount of potassium? Lol I have no idea how to describe it.