Potatoes that float or sink, starch content

The friendliest place on the web for anyone that enjoys cooking.
If you have answers, please help by responding to the unanswered posts.

redmike

Senior Cook
Joined
May 4, 2006
Messages
120
Location
Nazaré, Portugal
Just been looking for an article that properly explains how to prepare a brine solution to gauge whether a potato is high or low starch.


All the ones that I found are similar to this.

"If you are not sure which type you have, put one in a brine of one part salt to 11 parts water (11 fl oz water and 2 TB salt). Waxy potatoes float, mealy potatoes will sink."

But which kind of salt?

The volume of 2 tbs of coarse (kosher) salt is completely different to 2 tbs of table salt.

Any ideas?

Thanks
 
I tried just now and my boiling potatoes floated but I don't have any baking potatoes to test it on, and will look for some later. Right now they're harder to find, for whatever reason.

I used double the amount of coarse salt.

The skins on the above potatoes are easy to scratch off with a fingernail which is the test I normally use.

Dissolve 3.8oz, 120g of salt into 2 US pints / 1 liter of water.

The above seems better and I don't think it will matter if you use coarse or table salt.
 
I tried just now and my boiling potatoes floated but I don't have any baking potatoes to test it on, and will look for some later. Right now they're harder to find, for whatever reason.

I used double the amount of coarse salt.

The skins on the above potatoes are easy to scratch off with a fingernail which is the test I normally use.

Dissolve 30 oz, 90g of salt into each 2 US pints / 1 liter of water.

Baking/frying potatoes will sink in this brine solution.

Potatoes for boiling and salads will float.

Dissolve 3.8oz, 120g of salt into 2 US pints / 1 liter of water.

The above seems better and I don't think it will matter if you use coarse or table salt.

But a pain to have to use two different brine solutions.
 
ATK has the same ratio.

1 TB Table Salt = 1½ Tb of Morton's Kosher = 2 Tb Diamond Crystal.

P.S. High starch and low starch potatoes usually look fairly different.
 
Last edited:
Out of curiosity, why do you feel the need to test them? As a general rule, I use red or gold, or sometimes new white potatoes for boiling or to cut up and roast, and russets for baking.

I admit to not being an expert or a connoisseur of potatoes, and none of that is a hard and fast law.
 
ATK has the same ratio.

1 TB Table Salt = 1½ Tb of Morton's Kosher = 2 Tb Diamond Crystal.

P.S. High starch and low starch potatoes usually look fairly different.

My first reaction was "Huh?" so I did a little investigation. Turns out there is quite a difference between different brands, which I never knew.

http://dinersjournal.blogs.nytimes.com/2010/04/28/warning-measure-your-salt/?_r=0

not all salts are created equally | tips

That said, an ounce of table salt = an ounce of Morton's = an ounce of Diamond Crystal
 
Out of curiosity, why do you feel the need to test them? As a general rule, I use red or gold, or sometimes new white potatoes for boiling or to cut up and roast, and russets for baking.

I admit to not being an expert or a connoisseur of potatoes, and none of that is a hard and fast law.

Well it's very important to use the right ones and the color is not at all a reliable guide.

Scraping with your fingernail is pretty reliable.

If you can easily scrape the skin off with your fingernail, then they are most likely best for boiling, scalloped, or potato salad.
 
Potatoes in Portugal may be different from those we see in the USA. Here's a helpful chart. Cook's Thesaurus: Potatoes

Well if there not named you can only scrape with a fingernail.

Don't think going by the color is very reliable.

Sometimes small sacks are marked here for baking and boiling which is fine if you want to buy a small sack ;-)

Going to make a potato salad now.

New York Style Potato Salad

Serves Approximately four as a side dish.

2 lbs / 1 kg of unpeeled similar sized low starch potatoes.

The Marinade

9oz, 240g white vinegar - approx. 1 cup
5oz, 150g sugar - approx. 3/4 cup
1 yellow onion coarsely chopped
Salt and pepper to taste when adding the mayonnaise

Wash and boil whole potatoes checking for doneness after about 20-25 minutes, strain and set aside to cool.
Boil the marinade ingredients for five minutes.
Chop or slice the potatoes into bite size chunks.
Strain the marinade, and set the onions aside.
Add the liquid to the potatoes, don't add the mayo.
Marinade for 24 hrs in the fridge or for at least a couple of hours.
Stir once or twice if you remember to do it.
Strain the potatoes and optionally add back the onions.
Stir in mayonnaise (less is better than too much) and table salt and black pepper to taste.

When are the potatoes cooked? Stick a sharp pointed knife into the center, lift the potato and if it falls off, it's done. 210°F, 99°C internal temperature.
Which potatoes to use? Yukon Gold or red, but avoid russet (baking) potatoes if you can, because they aren't waxy and they tend to fall apart.
Diced potatoes will cook faster, but when you cook the potatoes whole, they maintain more of their flavor and natural sweetness.
 
I didn't know there was a New York-style potato salad ;) and I've never heard of marinating potatoes. How much liquid are you marinating them in?

All potatoes in grocery stores here are identified by type. Even at farmers markets and farm stands, there's usually a sign identifying the type of produce.
 
Last edited:
I didn't know there was a New York-style potato salad ;) and I've never heard of marinating potatoes. How much liquid are you marinating them in?

All potatoes in grocery stores here are identified by type. Even at farmers markets and farm stands, there's usually a sign identifying the type of produce.

I don't live in America anymore ..

New York Style Potato Salad

Serves Approximately four as a side dish.

2 lbs / 1 kg of unpeeled similar sized low starch potatoes.

The Marinade

9oz, 240g white vinegar - approx. 1 cup
5oz, 150g sugar - approx. 3/4 cup
1 yellow onion coarsely chopped

The Salad

Table salt and black pepper to taste.
Mayonnaise to taste.

Wash and boil whole potatoes checking for doneness after about 20-25 minutes, strain and set aside to cool.
Boil the marinade ingredients for five minutes.
Chop or slice the potatoes into bite size chunks.
Strain the marinade, and set the onions aside.
Add the liquid to the potatoes, don't add the mayo.
Marinade for 24 hrs in the fridge or for at least a couple of hours.
Stir once or twice if you remember to do it.
Strain the potatoes and optionally add back the onions.
Stir in mayonnaise (less is better than too much) and table salt and black pepper to taste.

When are the potatoes cooked? Stick a sharp pointed knife into the center, lift the potato and if it falls off, it's done. 210°F, 99°C internal temperature.
Which potatoes to use? Yukon Gold or red, but avoid russet (baking) potatoes if you can, because they aren't waxy and they tend to fall apart.
Diced potatoes will cook faster, but when you cook the potatoes whole, they maintain more of their flavor and natural sweetness.
 
Back
Top Bottom