Currently I am reading up on dough acidity and what happens with what enzymes and microbes in our dough. What are they all up to?.
A pH meter measures the acidity in our dough, more or less. And at different acidities different things happen. We can use this information to get better bread.
Some online Tech. Geeks still promote pH meters as a crucial instrument in assessing our bread fermentation. There are serious flaws in their reasoning. I mainly rely on my pre-installed meter… It’s called my nose and tongue. We can learn a lot about our dough by tasting and smelling it at different stages of the fermentation.
What is interesting is that yeast reduces the dough’s acidity, just enough to get it to the right acidity window, or range, for it to be at its maximum activity. What is also interesting is that yeast does not create very much acidity and so will never inhibit itself, unlike natural leavens.
The downside?
Good bread flavour largely comes from organic acids produced by the yeasts and the microorganisms in the dough. These react with the alcohol, produced by the yeast, to develop a lot of flavour compounds. The low acidity produced by yeast means less of these fuller flavour compounds when compared to Natural Leavens and all of their acid producing LAB microbes, but they are still there and we can use that.
The reactions between organic acids and alcohol is slow. This is why long fermentation and cold fermentation is so important for flavour development. They give these reactions time to take place. Long fermentation can be achieved by using less leaven and fermenting at cooler temperatures.
What we can do
When using instant yeast consider cutting the dosage down to 0.063g x the weight of the flour in your dough. This is actually the bottom of the recommended dosage for normal fermentation. We can easily halve that. In easy terms that is 1Tsp of instant yeast / per 500g of flour. Consider using ½ tsp.
Next ferment at lower temperatures, if you can. 24C / 75F gives good progress to the fermentation without being over slow. 26C / 79F is fairly quick and at 28C / 82F the fermentation is rather fast.
For those in hot climates I see that professional bakers often use crushed ice in their dough water, sieving off the water they need.
When I get to it I plan on trialling vinegar in my instant yeast dough. This is an organic acid too. The recommended usage is about 1.5% of the total flour used. That is 7.5g for 100g of flour. I have seen people use up to three times that amount. Be wary of using too much at the usual dosage it cannot be tasted in the finished bread. Too much and the loaf ill have vinegar notes. Consider using a live vinegar such as live apple vinegar. The Acetobacter will continue their work in the dough, to a slight degree. They need oxygen to work properly and there is precious little of that in fermenting dough.
Vinegar, as with all acids, increases the elasticity of the dough which can lead to a lower loaf volume. Some folk might want to increase the amount of water they use or add a small scald, say 10% of the flour, to the process to counteract that. For those of us who bake with weaker flours, we just got a bonus.
For those of us with hard water (alkaline water) a little vinegar will likely help the yeast to get the dough just slightly acid (pH 5 - pH6) where it can ferment properly. Yeast likes a sligtly acidic environment. pH7 is neutral acidity and hard water can be as gigh as pH8 or so.
Is your water too hard?
Hard water is alkaline, the opposite of acidic.
There is one very useful use for measuring the pH and that is for the water you bake with.
Neutral, neither acid not alkaline is pH7. Yeast likes an acidity of pH4.0 – pH 6. With a pH number over 6.0 the yeast cannot ferment very well. Hard water can be anything up to pH8.
If you think your dough is not fermenting very well, you can check the pH with some narrow range pH strips. They are inexpensive and are readily available online. Get the ones which measure from about pH4 – pH 8.0. They will give more accuracy than the ones measuring pH1 – pH11.
Just wet one with the water you use and check the colour of it against the colour code on the packet.
Your yeast does increase the acidity so it might be that it can correct slightly alkaline water. To check this press a strip against your dough, after it has fermented for a while, until it is damped, then read off the acidity on the colour chart.
If your dough ferments well, you do not need to do this. If you decide that hard water is a problem then consider using vinegar to correct the pH a little, or increasing the yeast dose.
The easier option is to use bottled water for the dough.
I use water with a pH of 7.4 and instant yeast has no difficulty getting that down and within the good fermentation range.
Natural Leavens
Those of us who use Natural Ferments are home and dry as the LABS are already doing the heavy lifting, as long as we give the dough time in a nice long bulk ferment.
Yeast is convenient, reliable and easy to use. However, it is like a one man band. Bread baking works so much better when lactobacillus is present. An easy way to use a natural leaven is to use an Old Dough. The method is reliable and involves no more than popping a little of the dough into the fridge when it comes time to shape the loaf.
I plan to write a longer article on acidity and dough development with natural leavens. With natural leavens the acidity is over ten times that produced by yeast alone. At that acidity level the final bread does not taste ‘Sour Dough’. The French and German artisan bakers do some interesting things with their natural leavens. All easy to do. That will be included.
And, yes, I have just obtained a pH meter. (Face palm) much of what I write about is drawn form research papers, empirical work and years of baking bread. Bread is a craft and the behaviour of the dough, its look, feel, smell and taste tells us everything we need to know. A pH meter does not replace a feel for the dough and its development.
Happy baking!