Common acids
Acid | |||||||
H+ ions | Name | Base Formula | pKa1 | pKa2 | pKa3 | pH of 1mM | Molar mass (g/mol) |
mono- | Lactic | C3H6O3 | 3.86 | 3.51 | 90 | ||
mono- | Acetic | C2H4O2 | 4.76 | 3.91 | 60 | ||
di- | Tartaric | C4H6O6 | 2.99 | 4.40 | 3.18 | 150 | |
di- | Malic | C4H6O5 | 3.40 | 5.20 | 3.33 | 134 | |
di- | Succinic | C4H6O4 | 4.21 | 5.64 | 3.65 | 118 | |
tri- | Citric | C6H8O7 | 3.13 | 4.76 | 6.34 | 3.24 | 192 |
Lactic and acetic acids - by products of heterolactic fermentation e.g., sourdough cultures, pickles, cheese.
Lactic acid - Dairy fermentations e.g., cheese, sour milk, yoghurt, silage.
Acetic acid - vinegar, pickles, kombucha.
Malic, citric and tartaric - common fruit acids. Malic acid and citric are the most common major fruit acids. Tartaric is the principal acid of grapes and raisins. Citric is the major acid in citrus fruits.
Succinic acid - byproduct of yeast fermentation.
What effects do lactic and acetic acids have on dough? - both acids show a tightening effect on dough, or put another way, both acids can be shown to decrease extensibility of doughs. However, while lactic acid increases elasticity, acetic acid tends to increase resistance and make the gluten short and hard. The effect of the latter can cause gluten to rupture during dough handling or even as it rises.