The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Salt-stressed yeast increases rise?

leucadian's picture

Salt-stressed yeast increases rise?

I just ran across this story about using yeast that has been exposed to a 7% salt solution for 40 minutes. Apparently the resulting bread is softer and faster rising. While this is desirable for commercial bakeries (faster, bigger, softer), it doesn't look like it's going to be a hit with the artisan baking community (maybe shift the retarding phase to the freezer??). But perhaps for those sugar laden pastries, or 100% whole wheat breads, it might be a useful technique.

Note that at 7% salt, I'd want to use only about half of the total water in the stressing solution. (Assume a 1.6kg dough, and 60% hydration. That's 1kg flour, 600g water. Two percent bakers math salt is 20g in the entire recipe. A 7% solution would require 20/.07 = 286 grams of water, with the remaining 314 grams added with the flour. Upping the water to 300g -half of the total water- would yield a 6.7% solution, and would make the measurements a lot simpler.)


from the article:
- 'Commenting on the mechanism, the researchers report that exposure of the yeast to salt solutions leads to an accumulation of glycerol in the cell membranes. Increases in volume may be due to "glycerol acting as a lubricant for the gas bubbles, allowing greater expansion", suggested the Taiwanese and Rutger researchers.

- "Specific volume increased with increasing levels of glycerol. Therefore, the larger loaf would have a less dense gluten network giving less resistance to compression," they said.



rick.c's picture

Think this would have an effect on a sourdough culture?  It could be worth a try.  I already keep hoochie mamma starved & cold in the fridge to make her work harder, maybe introduce the equivalent of crack to make a super producer.  But, what to call it?


spsq's picture

In a nutshell, what does this mean for the home baker?  I've been led to believe that salt retards the rise of bread, so in my ww loaves, I've always added towards the end of kneading time, hoping the gluten is stronger and the bread will have improved rise.  Does this mean the opposite is true?

rick.c's picture

My thought process is that exposing the yeast, etc to a saltier solution would propogate the breeding of yeasts that are more aclimated to a saltier soltion.  Then, when you put them into a normal solution, watch out!  Kinda like playing with evolution and forcing natural selection.  I might be a dreamer, but that is how I make sense of it.


Mini Oven's picture
Mini Oven

like if I'm stuck with high gluten bread flour and want to make a dough that is softer and less chewy.

I would half all your measurements for a trial and make two loaves side by side.  I might mix up the starter and water and divide into two mixing bowls.  Then add 10g salt to one  mixture for the first 40 minutes.    If the salt speeds up the process to under 6 hours, I would then be tempted to retard in the fridge to lengthen the fermenting time.  It might be interesting to see if there is a great crumb difference.  

So the yeasty beasties are tricked into making a protective thicker wall out of glycerol to prevent loss of their own cell fluid being drawn to the saltier solution.   Now if they are making glycerol, what is not happening in the dough?   Is something else going on as well?  As molecules are being used to make glycerol is another process being interrupted or eliminated or started?  After the initial 40 minutes, is the glycerol reprocessed or does it stay glycerol?


bottleny's picture

I was curious when seeing this sandwich bread (toast) recipe. Then found out the study regarding the salt-stressed yeast.

The recipe uses part of water as salt-yeast solution, with 10% salt (by weight with respect to the solution) and yeast (2% in Baker's percentage), which is stored at 5C for minimum 4 hr, before the main dough process.

The study claimed that the salt-stressed yeast leads a softer and bigger bread. Then this might be good for making a sandwich bread? I haven't tested it, but share the information here for someone who might be interested.