Effect of salt in bread baking
I have a very technical question concerning salt used in making bread. I know that high sugar content can retard yeast and that is why osmotolerant yeasts are used in these situations. Does salt act in the same way to retard yeast (i.e., increasing osmotic pressure)? More specifically, are the effects of salt on yeast and gluten a function of the sodium ion in the salt, or are they a function of the overall ionic concentration of the sodium and chloride ions (“ionic strength”) in the dough?
The reason I am asking is whether “lite salts” (blends of sodium and potassium chloride) in the same amount produce a comparable effect on the yeast and gluten. I want to reduce the sodium content of breads, but do not want to cause the effects mentioned above. I have tried researching this question online, but I have yet to find a definitive answer.
Thank you.
I realize that this response does not fully address your question but may be of some value to you. The reduction of salt in the bread I produce ( I suppose on the order of 200 loaves a year) has been one of my goals as well. While I normally see the salt content of commercial products in the range of 8% to 16% I also regularly see values as high as 36% (daily value on the nutrition label). I am currently using a baker's percentage of 1.6% for my recipes which seems to work.
In my rather sparse collection of books on break making I have found the discussion on page 16 of 'ARTISAN BREADS At Home with the Culinary Institute of America' 2010 by Kastel and Charles the most helpful.
According to this source salt adds flavor, strengthens the gluten, controls the activity rate of yeast and helps brown the crust. They note that below 1% to 1.5% the yeast will ferment faster but you will have tacky dough and the loaf will lack color. Above 2.8% to 3.2% the dough will be tighter and yeast will ferment more slowly. This leaves a rather small useful range they suggest of 2% to 2.3% which would translate into a daily salt limit of about 8% per serving (based on a daily limit of 2000 mg).
While I would 'expect' your salt blends to have a similar effect, I am certainly not competent to provide you with a definitive answer. My only suggestion would be to do up some test batches and see what difference there would be in the result and possibly run the recipes through a nutrition analysis program. Normal 0 false false false EN-CA X-NONE X-NONE MicrosoftInternetExplorer4
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I hope this helps.
Thank you for the info. I have been experimenting with using either less salt or a combination of salt and lite salt to get the sodium level lower. I use the final dough/loaf weight and total added sodium and use that to estimate how much sodium would be in a typical slice.
How do you find 1.6%?
I am currently on 1.8%, which I am happy with, but not sure about going any lower.
Have you both seen the Weekend Bakery article on salt content?
Lance
Many baking sites that I have read about salt in bread say that NaCl salt is hygroscopic and that explains its effect on yeast. I worked as a lab chemist for over 30 years and never considered pure NaCl to be very hygroscopic, if at all. It might get slightly caked in the container, but does not turn into one hard chunk or liquefy like a typical hygroscopic salt. According to the Salt Association of the UK, NaCl is only hygroscopic above 75% relative humidity. Below 75% RH, it will dry out.
With additional search engine attempts, I finally found an excellent summary on salt’s effect on bread dough:
Salt in bread dough
I also found a scientific journal article that is a review of salt’s effect on bread. Here is the link for those interested:
Bakery Science of Bread and the Effect of Salt Reduction on Quality: A Review
Unfortunately, most or all of the articles cited in the review are behind paywalls, so I can’t delve deeper into the subject. From what I learned from the both articles, the effect of salt on bread is mainly due to the ionic nature of the salt and is not specific to the sodium ion. So I am going to try replacing NaCl salt with the common NaCl/KCl blend.
Thanks for sharing the link to that informative BBGA technical article. It suggests that the sodium ions are not so much involved in gluten strength as chloride ions.
I don’t have much to add, but since I had recently been looking up other research on the effects of salt in sourdough, I dug a little further and here are a few things I found.
In other literature searches, I'd come across this article, which cites research finding that NaCl or KCl (perhaps ionic strength in general?) inhibited growth of LAB more than sucrose at the same osmolality: Serrazanetti DI, Guerzoni ME, Corsetti A, Vogel R. Metabolic impact and potential exploitation of the stress reactions in lactobacilli. Food Microbiol. 2009 Oct;26(7):700-11. doi: 10.1016/j.fm.2009.07.007. Epub 2009 Jul 17. PMID: 19747603.
Maybe you only care about yeast, but they cite another article that discusses a potassium transporter (K+-ATPase) involved in pH homeostasis (van de Guchte, M., Serror, P., Chervaux, C. et al. Stress responses in lactic acid bacteria. Antonie Van Leeuwenhoek 82, 187–216 (2002). https://doi.org/10.1023/A:1020631532202). This illustrates that there may be biological effects that are specific to certain ions.
Focusing on yeast breads, there were numerous titles on sodium reduction in breads, of which the most relevant seem to be studies replacing NaCl with KCl (https://www.tandfonline.com/doi/abs/10.1080/09637480701782118), with calcium compounds (https://pubag.nal.usda.gov/catalog/389650), and a mix of potassium/magnesium/calcium salts (https://www.tandfonline.com/doi/abs/10.1080/09637480701331148) replacing 10-30% of sodium chloride and reporting equivalent acceptability scores from tasters. The full texts are behind paywalls but the abstracts are free to read and list high-level conclusions.
In summary, it seems that publications in the nutrition literature alone demonstrate the feasibility of your plan, and it’s unlikely that moderate substitutions will have a pronounced effect on dough properties, but as usual it will come down to how much is acceptable to your personal tastes. Please let us know!
--Tom
Tom, thank you for the additional articles. I don't know if you are aware that the article in the USDA link actually is open access and can be downloaded (click the DOI link on the USDA site). The authors found that a 50% Na reduction was possible with minimal differences in the bread. Your comments about other ions affecting the behavior of bacteria was the reason I was inquiring about salts. Many biological processes are dependent on specific ions for activation or suppression. Proteins especially are affected by ionic strength, pH, and specific ions.
I feel more confident in substituting other salts for sodium when I bake now. I had never thought to use magnesium or calcium salts for substitution, only potassium. I might experiment with calcium as I may have some CaCl2 and CaCO3. Magnesium salts are more difficult to use because MgCl2 is very hygroscopic and hard to find in food grade.
1.6% vs 1.8% .... I've seen little difference overall. I have tried bread with about 1% salt content which produced some negative comments from some people about the lack of taste.
Thank you very much for the article on salt. I found it quite useful.
JB
I would love to hear how your experimental loaves turn out. There is a flavor difference between the salts-NaCl and KCl. I wonder if that will come through on the finished bread? KCl has a salty taste to our palate but with a distinctly different metallic taste.
Looking forward to any research
I baked a loaf of Oatmeal Bread from Laurel's Kitchen Bread Book earlier this week. The recipe was scaled to target a 730 g final dough. I replaced the salt with an essentially equal amount of Morton Lite Salt (290 mg Na vs 590 mg Na in salt). Here is the baked loaf:
The loaf color does not seem to be affected by the salt blend. The loaf may have been slightly under proofed but I have recently had a couple whole wheat loaves collapse from over proofing, so I popped it in a little early. The flavor of the bread did not seem to be affected by the salt blend, but I have not made a control loaf with regular salt, so I cannot compare directly. An independent taster who is more sensitive to bitter or off flavors said the bread tasted fine.
I'm re-learning some yeast bread techniques after 30 years of not baking and learning new ones on the 100% whole wheat breads.
Glad to see it turned out so well. That could make a big difference in dietary sodium intake! Thanks for sharing your results.
The loaf looks fine and I am very interested to hear your independent taster's opinion b/c Lite Salt does taste very different to me.I may re-visit Lite Salt as it has been more than a few years since last tasting.
Thank you!
I have been using lite salt blends in cooking and at the table for many years, so I may be less sensitive to the taste of the KCl. I do have some Nu-Salt that is all KCl and I can taste the metallic note if I use too much on food. There is also mySalt that is KCl with the amino acid lysine. The lysine is supposed to mask the metallic note. I just bought some but I have not used it enough to decide on the flavor.
FYI, the final calculated Na content of the bread I made is 1740 mg in the 650 g baked loaf, or 120 mg in a typical 45 g slice.
Is your goal to increase production rate/speed or lower the cost of ingredients?
If not, the primary purpose of salt is flavor. 1.8%-2.0% is a common salt weight:flour weight ratio for bread. It's based on what most people prefer, as established by both history and current custom.
Other salts besides NaCl may require lower weight:flour ratio because they have different flavor and strength.
Salt and salinity are similar to sugar and sweetness in baking. There are common weight percentages, mainly influenced by flavor. And in the case of commercial producers, their effects on production output and cost of ingredients.
What is your fundamental aim?
While you await Alcophile's reply, I would like to make the point that surely no salt substitute is likely to be cheaper than NaCl?
Lance
@semolina_man
My goal for sodium reduction in bread is for health reasons. Bread is one of the foods implicated in high Na intake and with few exceptions, most commercial breads are relatively salty. My rule-of-thumb is 1 mg Na per 1 food calorie. That way the daily Na intake is close to the recommended value (2300 mg, 1500 mg preferred).
I decided to make my own bread to control Na intake. I read that Na plays important roles in the process of making bread and I was concerned that reducing the Na content and/or replacing it with other ions would negatively affect the yeast or the gluten, in addition to flavor. What I found was that saltiness (aka ionic strength), regardless of the identity of the ions, is more important. I can now experiment by adding less NaCl salt or with other salts (like LiteSalt).
Early in my bread baking journey, I was taught to avoid iodized salt. Supposedly the iodine can kill or at least inhibit the yeast or sourdough cultures. So I always use fine grain sea salt. Also I add it after the autolyse step, because it can interfere with the absorption. But beyond that, I know nothing of how it reacts with the dough. Following this discussion to learn more.
@Sandy V
I have not noticed any effect on the the breads I have made with iodized salt. I am not working with sourdough only yeast. Iodide is much more easily oxidized than chloride so it could get involved in some chemistry during all the mixing/kneading. It may also affect bacteria more than yeast(?).