What does vinegar add to a mix?

vinegar in dough

pickle juice

I add vinegar to the dough for my Double Crusty bread, not a sourdough, and it gives the bread incredible lift.

Hi Bunjie,

Vinegar [acetic acid] is primarily added to commercial bread dough as a preservative, as it lowers the pH of the dough.   It can be added at a level up to 1.25% on flour, but beyond that it will impact in terms of the taste of the finished bread.

Acid also has a strengthening effect on the dough as you have noted, so vinegar does can also be added for this reason too.

Best wishes

Andy

Was it in the '60's ? Vinegar was good for the yeast or something like that. I have a self-published cookbook from an author that added fresh ginger to every loaf because that was "good for the yeast". She used modern,dried yeast and I believe she published this in the same era-60's or early 70's. It was typed on a typewriter.

A search is always a good thing. There are many reasons to use an ingredient and it can be very  educational to see all the different posts and ideas. 

I add vinegar to almost all of my gluten-free yeasted doughs.  It really helps the bread to rise better.  Yeast like an acidic environment, so the vineger is stimulating for them and makes them more active.  Vinegar is also a dough conditioner that improves the texture of the final baked good.  Usually recipes will call for apple cider vineger because of special enzymes this vinegar has, but I think any vinegar will do to add the acidity needed for the extra lift.  Ascorbic acid (vitamin C) is usually found in commercial breads for the same reasons.

Clazar, I have been experimenting with using ginger as a natural preservative in bread.  I use a very small amount, which is supposed to be at a level that is tasteless, but I'm finding that sometimes the taste comes through too much and I'm thinking of trying something else.

Hi GFG and clazar,

I always thought acid tended to inhibit baker's yeast.   Hence why sourdough yeast contains limited sacchromyces cerevisiae and is noted for utilising yeast strains such as candida millieri and sacchromyces exegus...strains which can tolerate more acidic conditions.

Best wishes

Andy

Vinegar does not increase the fermentative activity of Saccharomyces cerevisiae.  Different acid types affect this yeast strain differently; concentrations of acetic acid (vinegar) above .6% begin to have an inhibitory effect on cellular reproduction, glucose consumption, and, as the concentration increases, an exponential increase in lag time is observed  (Narendranath, et al, 2001).  Yeast have acid-stress response mechanisms, and S. cerevisiae will begin to show these stress signs at acid values as low as .05%.  If concentrations are high enough, cell death may even occur.

What vinegar does do, like all dough oxidisers, is alter the dough rheology by effectively tightening the glutenin and gliadin, making for a prematurely strong dough with increased fermentation tolerance.  Thankfully, strains of S. cerevisiae have evolved stress-response mechanisms to weak acids.

All acid types, though, will eventually display a deteriorative effect on gluten, if left long enough, which is the reason vinegar is often included in unyeasted feuilleté doughs, as it helps extensibility.

It should be noted that wild strains of S. cerevisiae act differently, and can easily become the dominant yeast strain in a sourdough culture, especially when Lb. sanfranciscensis is involved.

Yeast likes a neutral to slightly acidic environment.  I think we can agree that an alkaline environment is not good for yeast.  Perhaps the reason our answers don't mesh up is because we haven't really talked about the amount of vinegar in the dough.  I usually put 2 tsp of natural apple cider vinegar in a 1-pound loaf of bread.  I know from experimentation that there is no advantage to adding more.  The water in my area is slightly alkaline (7.2-8.2) so this amount of vinegar seems to put the dough into that "slightly acidic" enviroment that yeast thrive in, but isn't nearly enough acid to give the dough a sour flavor.  It may be true that baker's yeast isn't as tolerant of acid as a natural yeast, but we aren't talking about that level of acidity.

I find it interesting when I run across information on what elements strengthen gluten in a dough.  I often find that the same additives work for gluten-free dough as well.  There aren't any studies that I know of that demonstrate the effect of vinegar on gluten-free dough, but almost every recipe that I've seen for a gluten-free bread with a decent rise had vinegar in it.  Every commercial GF bread and baking mix I've seen have also had some sort of acid, usually ascorbic acid.

Thanks ars pistorica for a very informative post!

Gina

Hi Gina,

I think the reason for the apparent differences in our responses to this question comes from the original focus of our answers.

I was looking in particular at industrially-manufactured bread, which utilises an improver or dough conditioner made up of a number of chemicals and enzymes, each of which is added for a specific purpose.   Vinegar, or Acetic Acid is one of these and it is added as a preservative, because lowering the pH inhibits microbial activity.   Where vinegar is deemed insufficiently powerful, food manufacturers would add Calcium Propionate or Potassium Sorbate in its place.   Dough strengthening is achieved through the addition of L-Ascorbic Acid and enzymes.   Yeast activity is encouraged through the addition of yeast foods; these being chemicals such as Ammonium Sulphate, Ammonium Chloride and Ammonium Phosphate.

Your particular context was Gluten Free Baking.   It is good to clarify that your experience is that the improvements you note in Gluten Free dough comes about from the addition of small amounts of vinegar.   Pyler [my editions come from 1988 (volume 1) and 1973 (volume 2)] confirms what you say about yeast functioning most happily in a slightly acidic environment, with pH of 5.8 - 6 seemingly optimal [I assume this is for industrially-produced Sacchromyces Cerevisiae used in large-scale bread production].   Pyler also suggests that yeast is relatively tolerant of this acidic environment, but only for a short period of time.

I am really interested to see what effect this discussion might have on your future bread baking.   I very much agree with you that the inclusion of an acid in Gluten Free bread is common, and its benefits are manifest.   Vinegar is the most common one I have seen used in recipes intended for home use, and, it is the one we used at Village Bakery when we first started making Gluten Free Bread as the year 2000 approached.   This recipe was "no time", and quick fermenting.   So, the benefit of the acid as discussed in this context does indeed stand up.   But what of using longer fermentation processes in respect of Gluten Free?   It's something I have no experience of, but also something I believe you are very keen to investigate.   Longer fermentation will generate an acidic environment over time, so it will be interesting to read what you find about any potential role for vinegar, or ascorbic acid.    I suspect they will become redundant just as is my experience with wheat-based dough.

All good wishes

Andy

Thanks for the info AP,

I always thought that freshly-mixed dough as you describe was slightly acidic; good to have that quantified.   So would any addition of vinegar have an immediately negative impact on yeast activity, or could one add a very small amount before yeast activity became compromised by the acetic acid to any sort of extent?

Best wishes

Andy