Dried Pasta, Water and Salt

Table of Contents

• Cooking Dried Pasta
  • Pasta
  • Dried
• Culinary Advice
  • Recommended Practices
  • Culinary Writing and Publishing
  • Web Forum
• Science
  • Search
  • VTI Paper
  • The Culinary Sources’ Advice
  • Public Health Guidance, Flavor and Appetite

Cooking Dried Pasta

Pasta

Pasta is a starchy food products that has been cooked in Italy for centuries. Other food productd made with wheat – e.g. couscous – are known in countries around the Mediterranean.

Italian buyers have favoured semolina, a coarsely ground flour ground from Durham wheat, a hard, high-protein wheat. Modern “fresh’ pasta recipes for pasta dough for manual and electric pasta machines (that press and cut the dough) call for some semolina, some lower protein “soft” flour (e.g. US “all purpose”) or white bread flour, and water. Some recipes call for some salt, and for eggs to make egg pasta noodles. The dough recipes are similar in proportions of flour and water to bread formulas

Wheat flour will form gluten when water is added, which makes the dough extensible and elastic. Pasta is an unleavened product; the dough, made of flour and water, does not ferment or rise. Dough is pressed and cut into noodles. Gluten makes the noodles hold their shapes. The noodles are cooked in boiling water. Fresh noodles may have to be cooked fairly soon; industially manufactured fresh pasta has become a refrigerated product available in grocery stores.

Dried

Dried pasta was developed by Italian manufacturers in the 19th century and the early 20th century. It is more durable than fresh pasta. It is made by mixing flour and water into dough, extruding the dough through dies, cutting it, moving it on conveyor belts to drying machine, drying it and packaging the dry noodles. The Wikipedia article pasta processing provides an overview. Whole wheat and gluten-free dried pasta products became available during the late 20th century. Dried pasta generally is made without salt and has very little sodium.

Dried pasta noodles vary: long, short, and shaped. Noodles gain weight and volume when cooked in water. Dried pasta of any given weight generally absorbs about the same amount of water as the same amount of differently shaped dried pasta. The Dry to Cooked Pasta Calculator: A Comprehensive Guide at the Lyn’s Kitchen site provides the amounts of gain, by volume, in tables. Four US ounces (112 g.) of dried elbow pasta (macaroni), a short pasta, which is one US cup by volume, yields 2.5 cups of cooked pasta. (The same amount, by weight, of dried long or shaped noodles yields different volumes of cooked pasta.) The tables at that site do not estimate the weight of the wet, drained, cooked pasta. The USDA tables, discussed below, suggest that the main difference between 100 g. of uncooked and cooked dried pasta is that cooked pasta has an additional 51 g. of water, suggesting that less than 50 g. of dried uncooked pasta gains over 50 g. during cooking.

The USDA FoodData Central data has nutritional information about some cooked pasta in the Survey Foods (FNDDS) and Legacy Foods (2018) databases. and states nutritional information for a stated volume (e.g. 1 cup) or weight (100 g.). The Legacy Foods data has separate entries for uncooked dried pasta and salted cooked pasta. Noted with respect to 100 g. of uncooked dried pasta or cooked pasta:

• uncooked dried pasta contains about 9 to 9.9 g. water;
• cooked pasta contains about 62 g. water;
• dried pasta cooked without salt has 1 mg. of sodium; and
• dried pasta cooked with salt has 131 mg. of sodium .

Culinary Advice

Recommended Practices

Many culinary sources discuss the best practices for cooking dried pasta: to drop dried pasta in boiling water and drain it when the pasta has been hydrated and cooked al dente (which may vary from the time specified by the manufacturer). The sources vary on the amount of water. The majority recommend a gallon of water (4 US quarts, or 16 US cups, by volume) for one pound (454 grams) of dried pasta. A pound of dried pasta is said by many culinary writers to be enough for four servings of cooked pasta. A US gallon of water weighs about 3,800 grams, and has a volume of 3.785 liters. A cook may decides to use less cooking water:

• to cook less than 1 lb. of dried pasta, or
• to use a recipe or method that uses less water for other reasons.

Low-salt and other health oriented cookbooks (e.g. The American Heart Association’s Low-Salt Cookbook) counsel against salting pasta water while most culinary sources advise the home cook to cook the pasta in salted water to make the pasta taste better. Older culinary sources say that pasta has been traditionally cooked in water “as salty as the sea” but modern sources dismiss that standard. Some sources also say salt slows the gelatinization of starch in the pasta and makes the pasta more firm. The majority of culinary sources recommend 1 Tablespoon (3 tsp.) or 4 teaspoons (of ordinary table salt – i.e. made of moderately fine crystals) in 1 gallon. A printed example: The Complete Italian Vegetarian Cookbook, (1997) by Jack Bishop. Web sources:

• America’s Test Kitchen (Cooks Illustrated) How Salty Should Your Pasta Water Be,
• Martha Stewart Why you should salt pasta water

1 Tablespoon of table salt weighs 17.1 grams. 1 Tbsp. of salt
dissolved in water adds to the total weight of the cooking water by
about .005. It contributes 6,720 mg. of sodium ions to 1 gallon cooking
water. Some of the boiling cooking water evaporates, and some is
absorbed by the pasta. There is a question about how much
sodium dried pasta absorbs when cooked in salted water.

The America’s Test Kitchen/Cook’s Illustrated site, a culinary site, minimizes the sodium added by cooking dried pasta in salted water on the basis of “independent” testing. But, it did not say how the test was conducted and state the results:

Adding salt to pasta’s cooking water ensures that the pasta is
flavorful. Throughout the years we’ve zeroed in on a preferred ratio of 1 tablespoon of table salt to 4 quarts of cooking water per pound of
pasta for the most well-seasoned pasta of any shape or size.

Give or take a few milligrams of sodium, all the shapes absorbed about the same amount of salt: 1/16 teaspoon per 4-ounce serving or a total of 1/4 teaspoon per pound of pasta. … even if you are watching your sodium intake, the amount pasta actually absorbs is so
small that it’s probably not an issue.

How Much Sodium Does Salted Cooking Water Add to Pasta?

An article published on the culinary MarthaStewart.com web site suggested the amount of sodium added to pasta by cooking it in water with 1 Tablespoon of salt was minor:

Sodium patrollers can rest easy knowing that your pasta will not absorb the full tablespoon of salt. In fact, a pound of pasta is estimated to absorb only about a quarter of that amount.

Rebecca Morris, updated by Victoria Spencer, Why you should salt pasta water, MarthaStewart.com

The estimate of a quarter of a tablespoon of salt is not explained. This would be 4.3 grams, which would include nearly 1,700 mg. of sodium. This works out to 425 mg per serving, which is not alarming but is a significant amount for one course of one meal in a day.

Culinary Writing and Publishing

“Tastes better” is an opinion delivered as culinary advice.

The culinary sources above implied there is scientific evidence that cooking dried pasta in salted water does not present health concerns for consumers. The sources have failed to identify the experimental evidence or papers that anchor their opinions. If the writers, editors and publishers understood the heatlh risks, they might have said what they knew. The culinary publishing industry has not been giving advice based on food science or medical science.

The culinary sources suggest that cooking dried pasta in salted water does not add much sodium in terms of the US National Research Council’s Recommended Daily Allowances (“RDAs”). The RDA for sodium is 2,400 mg. (or 1,500 mg. for many individuals). The legal and regulatory context:

• there is no law against sodium in cooked pasta or adding salt to dried pasta through the cooking water; but
• sodium in cooked pasta or salt added to dried pasta through the cooking water is not “approved” or recommended by US authorities.

The RDA is not a government standard for sodium in food. U.S. public health guidance warns about sodium in prepared, processed and cooked food and requires disclosure of sodium by the manufacturer or seller of a packaged product in precise terms.

There is no law or regulation requiring a culinary writer to explain the consequences of following a tradition, a recipe or advice on cooking. There is no RDA for culinary advice from journalists.

Web Forum

A threaded discussion in the Seasoned Advice site (“a question and answer site for professional and amateur chefs”in the StackExchange network) of the question “When cooking pasta in salted water how much of the salt is absorbed” began in 2010. The discussion includes a couple of published scientific research papers, some theories, and a little math. The references in that discussion to scientific sources:

• “Contents and Retention of Sodium and other Minerals in Pasta Cooked in Unsalted or Salted Water” a paper published in Cereal Chemistry, the journal of the Cereal & Grains Association, in 1986, and
• “Changes in Sodium Content in Potatoes, Pasta and Rice with Different Cooking Methods” a report written for the Scottish Food Standard Agency in 2006. The report is not in the publications of Food Standards Scotland in 2024. The report is in the Internet Archive’s Wayback Machine, but that service often returns a 503 error – “no server available” – to requests. There is a copy in the USDA National Agricultural Library at https://www.nal.usda.gov/research-tools/food-safety-research-projects/change-sodium-content-potato-pasta-and-rice-different.

Science

Search

A seach engine search can lead to the Seasoned Advice discussion. Finding other papers published in scientific journals about the salt in pasta cooking water with a search engine is not easy. Understanding or applying a paper is not easy. Food scientists writing for publication in academic journals do not explain the effects of cooking in the terms used in culinary writing. I located a paper that addresses, and seems to answer, the question, by searching the citation of the 1986 paper in Cereal Chemistry.

VTI Paper

There is a paper published in Food Chemistry in 2019: “Cooking parameters affect the sodium content of prepared pasta” (“VTI paper” – some of authors were at the Virginia Technical Institute at the time). It was based on experiments cooking one pound (454 g.) of dried spaghetti pasta, and other pasta samples in 6 quarts (1.5 gallons) of unsalted water, and salted water. The VTI experiments tested pasta made from wheat. Some pastas are made
from rice or other gluten-free starch products. Some dried pasta
products may have more sodium or take up more sodium from salted cooking
water (as discussed in the 2006 report to the Scottish Standards Agency
noted above).

The VTI paper discusses cooking by a reference method (“Ref.” M.”): adding 36 g., ¹the team used the conversion factor of 1 Tbsp = 18 g. 2 Tablespoons of table salt (Morton® iodized) to 6 quarts (1.5 gallons) tap water, bringing the salted cooking water to a boil, and cooking the pasta for 9 minutes. There were tests at several different concentrations of salt in water, listed in the table below. The team used a fixed amount of salt for a fixed amount of dried pasta in one control experiment. The VTI paper used the term “concentration of salt” of water (i.e. salinity, a specific mass concentration) in grams of salt in a liter of water (g/liter).

The VTI team did not test at the concentrations the culinary sources recommend, as such. These values are interpolated in the table below on the linear basis found in the paper (see below):

• 1 Tablespoon of table salt, 17.1 grams (some would say 18 g.); 4.52 g/liter.
• 4 teaspoons, 22.8 g.; 6.02 g/liter.

The VTI experiments tested for sodium in the cooked pasta:

Sodium was quantified using inductively coupled plasma spectroscopy-mass spectrometry (ICP-MS) after digesting the samples using a two-day, open vessel, nitric acid/hydrogen peroxide digestion procedure

The paper reported results by sodium in milligrams divided by the mass of the cooked pasta for 100 g. of cooked pasta and for 140 g. of cooked pasta. The paper correlates experiments and data by identifying the experiments with letters of alphabet. The results of experiments A, B, G, H, I, J can be listed in a table. the results and the interpolations are ranked in the ascending order of sodium in cooked pasta:

Test and salt	Salt g/liter	mg. sodium /100 g.	mg. sodium /140 g.
G – unsalted	0	≤5	≤5
B – 50% Ref. M.	3.17	91.2	128
H – Ref. M. & rinse pasta after cooking	6.34	115	162
Interpolation*: 1 Tbsp. /gallon	4.52	125.5 *	176.1 *
Interpolation*: 4 tsp. /gallon	6.02	167. 2 *	234.5 *
A – Ref. M.	6.34	176	247
I – 150% Ref. M	9.51	267	373
J – 2x Ref. M	12.7	350	490

The VTI paper noted:

…. Dry pasta is itself low in sodium, but significant and varying sodium content results from salt added during preparation. Reducing (or eliminating) the amount of salt added when cooking pasta and/or rinsing after cooking is a simple and quantitative way to reduce dietary sodium. The purpose of salt in cooking pasta is generally agreed upon to be for taste.

The VTI experimental results supported:

… a predictive equation for sodium in cooked pasta as a function of the salt concentration in the cooking water … based on differing amounts of salt added during pasta preparation, and whether or not the pasta was rinsed.

The connection between the concentration of salt in the cooking water and sodium in the prepared pasta was linear, i.e. it graphed as a straight diagonal line in graphs in the paper. The VTI paper suggested:

The linear relationship between the concentration of salt in the cooking water and sodium in the prepared pasta … can be used to obtain a more accurate estimate of the sodium content …

This information could also be communicated to consumers as demonstrable and simple way to reduce sodium intake, by relating how much salt in pasta cooking water increases sodium, and that rinsing after cooking could reduce by 1/3 the sodium content of pasta cooked in salted water

The Culinary Sources’ Advice

The VTI team did not test at concentrations that the culinary sources recommended – 1 Tbsp. or 4 tsp. of salt per gallon of water. The results suggest that the 1 Tbsp. would add about 125 mg. and 4 tsp. about 167 mg. of sodium to 100 g. of cooked pasta.

The culinary sources are justified in saying that salting a gallon of cooking water with 1 Tbsp. or 4 tsp of salt does not make the cooked pasta very salty, and in saying pasta cooked in water with salt at those concentrations adds sodium to the cooked pasta in amounts that can be calculated as in the table above. The sodium in 100 g. of cooked pasta is less than 200 mg.

Then, think about the size of serving. A serving of cooked pasta may begin as 100 to 150 g. of dried pasta, which swells in volume and gains weight. That serving of pasta may weigh 200 to 300 g. when cooked in water and may contain 350 to 500 mg. of sodium if the water has been salted to the level recommended by culinary sources.

Public Health Guidance, Flavor and Appetite

The VTI paper helps understand how much sodium a person who eats pasta cooked in salted water consumes. The paper does not prove that it is “safe” to eat pasta cooking in salted water. The health effects depend on the person, the concentration of salt, the size of the serving, and other variables.

Science-based RDAs and label warnings are not much use in preventing cooks from cooking with salt.

Cooks do not often:

• weigh or measure salt or water,
• know, let alone understand, the sodium or salt RDAs, or
• weigh the portions of cooked pasta.

Cooks commonly serve much more pasta than 100 g., topped with a sodium-rich sauce (highly processed and/or made with salt), accompanied by
sodium-rich food.