Can anyone tell me what adding vinegar to a dough mix does for the resulting mix. I presume it adds some sort of flavour but is there another reason?
This is a question out of the blue really. One of the YouTube videos that I watched about "No Knead" bread added some beer which I have no problem with, but also added a teaspoon of vinegar. Further searches intimated that this could be for flavour but also because there is an effect on the gluten. I am only looking for guidance!
Thanks for the quick response.
vinegar in dough
I add vinegar to the dough for my Double Crusty bread, not a sourdough, and it gives the bread incredible lift.
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.
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.
Andy - Gluten-free bread is often reluctant to rise. I couldn't get a decent loaf of bread before I started adding apple cider vinegar to my recipes. I have done recipe comparisons - usually on accident when I forgot the vinegar - and the loaves often didn't even work without the vinegar. Acid definitely works with commercial yeast. In fact, ascorbic acid is an ingredient in "quick rise" yeast because it helps to activate it.
I can't remember where I first read about using vinegar to get a higher rise, but here's another thread on TFL that talks about vinegar: http://www.thefreshloaf.com/node/11796/effect-vinegar-instant-yeast-dough
see response from ars pistorica below. Acid does not impact positively on baker's yeast fermentation. It is used in bread as a preservative because it suppresses microbial activity.
The comments about dough strengthening made by AP are key.
Many thanks for all your comments on what vinegar does to dough.
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.
helps extensibility? You mention the tightening effect so how can mean extensibility? Acidity increases elasticity and reduces extensibility...
Of course it does! What do you think proteolysis is? What do you think happens to a sourdough that has fermented too long? Why do proteins denature and coagulate in the presence of acid? Your assumption, mistakenly, is that the presence of acid only has one effect on a dough over time. The presence of acid at certain levels does have a strengthening effect, as it acts as an oxidiser (versus something that has reductive consequences), but only at certain levels and for a certain amount of time. Why do you think a lot of good puff pastry recipes call for the addition of vinegar? To increase elasticity? Why do eggs scramble in the presence of acid, or ceviche denature and achieve a "cooked" texture?
Do not conflate redox potential with a dough's rheology!
Certainly I agree that there is a tipping point and that coagulation is at the end of it. But the practical level of usage will not be sufficient to cause a meltdown and will only serve to boost strength.
Plus I'm not sold on the idea that the acid is acting as an oxidiser. I'm no scientist so I would be interested to read your explanation of this too...
EDIT: You'd be interested in my Italian starter as the discards that I've put into food waste are nearly a week old and it's still dough and not soup.
Certainly I agree that there is a tipping point and that coagulation is at the end of it. But the practical level of usage will not be sufficient to cause a meltdown and will only serve to boost strength.Certainly I agree that there is a tipping point and that coagulation is at the end of it. But the practical level of usage will not be sufficient to cause a meltdown and will only serve to boost strength.
Actually, coagulation occurs almost immediately! The constriction and then binding of proteins is what gives dough its premature strength. In puff pastry applications, for example, acid serves to prevent discoloration and helps strengthen the dough in the short-term, a special consideration since fats above 15% greatly increase a dough's extensibility and also because mechanical means may make the dough too tough. After a certain amount of time, however, the presence of acid then begins to have a counteracting effect, and thus increases extensibility.
Acids acting as an oxidising agent is universally accepted; just Google it.
By "Italian" starter I'm assuming you mean a 100:100:50 feeding ratio, like those used in Pannetone? The pH of such starters (remember, throughout Italy there are vastly different means of maintaining a starter on a professional level, and I say this with direct, personal knowledge) would be in line with what you're describing, especially if using a wheat flour with very low ash content.
Premature strength - What kind of time frame are we talking about? It must be a length of time longer than it takes for the dough to rise as it's not something I've noticed a problem with. I can only see my doughs getting stronger and stronger.
Typical formula for bread made using my Italian starter.
First dough (Biga acida): (8-10hrs room temp 18-20C)22.5% lievito madre (taken after 16hrs in a water bath)45% water100% flour
Second dough: (32C ~6hrs)50% biga acida78% water100% flour2.5% salt
As the final dough ferments and proves the acidity increase and the dough becomes visibly stronger. So strong that as a freestanding loaf it rises vertically.
Yes my Italian style starter is fed 1:1 (starter:flour) but at 48% hydration or less. A stiff starter is still the most common form of starter (lievito madre) and is the only type used for panettone production in Italy (not including chemical formulations). It's only in recent times that wetter starters are being used. The stiff starter is traditional and so are Italians.
That style of starter isn't necessarily Italian; it's very Massari (yes, I own both of his books, too).
Anyway, this is sort of off-topic, but I have found an answer to your other question, about how to limit acid-production. It took me awhile to find the actual percentage, but try .75% citrate (per 100% flour), which will effectively force a co-metabolism of both maltose and citrate, with the end result being very low acid levels.
edit for answer: different oxidisers have different times. ascorbic reacts faster, typically 1 hr after mixing.
It should also favor the release of dyacetil, if I'm not mistaken, that I've been hunting for a lot of time without success (to mimic a buttery flavour).
Thanks! I'll search it.
diacetyl isnt observed in obligate heterofermenters. your best hope would be to switch to a lb plantarum based culture as it will produce diacetyl. same 30 degrees but push refreshment times to 48h. lb sf should drop out but plantarum and fermentum will stay.
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!
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
acidification and having a very specific hydration to achieve the right viscosity for the resulting gel network to capture co2 production are two of the most important considerations in gf bread. btw, there are many, many studiea dealing with acidificatio and gf baking. do you have the eimar gallagher book?
acidification and having a very specific hydration to achieve the right viscosity for the resulting gel network to capture co2 production are two of the most important considerations in gf bread. btw, there are many, many studies dealing with acidification and gf baking. do you have the eimar gallagher book?
what protein sources are you using in your formula? denaturing proteins is important in gf baking to bind them to the starch-hydrocolloid-water network. rice flour has low amounts of protein. have you used soy flour or soy milk powder? longer sd ferments can generate sufficient exopolysaccharide production to help strengthen this network. this can be achieved with a good bulk and a long, retarded proof.
andy, the ph you mention is also coincidentally the final ph of freshly mixed water and flour!
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?
different acids affect yeasts differently. (eg, lactic leads to more repression in glucose consumption). the mininum threshold for inhibitory effects vary. the amounts for acetic are stated above. understand that some vinegar, like in traditional straight 100% rye doughs, is needed to destabilise proteins to allow them to more efficiently bind in the gel matrix. this is also a principal concern for gf bakers. sd does this naturally and better though so no vinegar would be needed in a sd gf bread.
a better to to measurenit is thus: straight yeasted doughs finish fermentation with a usual ph of 5.0-5.1.
of a document I read recently
claiming that low-protein rye flour is claimed to be better for baking rye bread, for unexplained reasons.
Moreover recently I prepared a bread where the preferment was a 250% hydratation rye paste kept above 30°C for 12 hours. Obviously it was sour as hell, as I intended. The flour in the final dough (90%) was a very weak wheat flour that generally can barely absorb 65% water, giving a less than decent bread. With that preferment I had to raise hydratation of the dough to 78% overall and the bread came out MUCH better than I ever thought possible with that flour. I was very surprised, i could never imagine that a rye preferment could even *improve* the rheology of a dough. I hope it was not just a case.
it can as long as it is acidified!
I have been under the impression that acidification of rye doughs was primarily to suppress amylase activity so as to not destabilize the starch gels before the bread has risen in the oven. There are probably other good reasons to acidify, but if you don't acidify a 100% rye dough you run the risk of baking a brick.
Acidification in rye doughs does more than I have mentioned, and even more than you have mentioned. For the purposes of this discussion, I was trying to show the analogy between 100% rye doughs and gluten-free doughs. Acidification leads to the solubility and eventual hydrolysis of mineral salts bound with phytate, and ultimately leading an increased bioavailability of dietary fibre found in rye. You are quite correct that acidification of 100% rye doughs suppresses endogenous enzyme activity, especially for whole-grain rye, but it should be noted that it is not limited to just inhibiting a-amylase activity. Gel formation means nothing without destabilised proteins (present in minor but sufficient levels in rye flour for this purpose), which help form a more complete air-trapping network. There are lots of other benefits, too, like the anti-microbial properties, etc., but most are outside the bounds of this discussion. Thanks for your clarification!