In the Kitchen
Tech Slices: Water as a dough ingredient
By Bob McDougall
Water as a dough ingredient
By Bob McDougall
For a long time many of us took water for granted. That
has changed a lot over the past decade or so, with municipal water
tragedies, heated discussion over exports of fresh water and the
incredible proliferation of bottled water worldwide. It’s hard to
believe we routinely pay as much for a glass of bottled water as for
the gas to drive 10 km or more.
For a long time many of us took water for granted. That has changed a lot over the past decade or so, with municipal water tragedies, heated discussion over exports of fresh water and the incredible proliferation of bottled water worldwide. It’s hard to believe we routinely pay as much for a glass of bottled water as for the gas to drive 10 km or more.
But pizza makers, like other masters of the art of baking, have never ignored water. It is one of only two ingredients without which no pizza can exist (the other being flour). Flour and water combined in the correct ratio will form dough. The starch and protein of the flour, together with the water molecules, make up the three-dimensional network.
All water used in dough must be clean and pure. Water that is not biologically safe, or is below drinking quality, cannot be used. Contaminants in water can grow rapidly in dough prior to bakeoff, generating large amounts of deadly bacteria or their poisons. The risk of not destroying, in the bake, all dangerous organisms or their toxic poisons is real.
Of course, chemical impurities, and even certain off-tastes and aromas, such as those from high-algae municipal water sources sometimes found in parts of the prairies, or mustiness sometimes seen in water from cities on the Great Lakes after prolonged heavy rains or spring runoff, can show up in finished crust.
The chlorine, chloramines and other compounds commonly used to treat water supplies can be considered chemical contaminants for the purpose of dough making, since they can definitely interfere with the ability of yeast to work properly in a dough system.
The solution for many of these issues can often be a high-quality polishing filter in the “dough water” line. If you serve coffee, you might want to use the same filtered water to feed that equipment as well.
As some are painfully aware, the hardness, or type and amount of dissolved minerals in dough water, is very important. The mid-range of hardness, around 50-100 parts per million (or ppm) of minerals is ideal. Ask your municipal water utility for the typical levels in your area.
Generally, water that is too hard (above 100 ppm) can lead to stronger, stiffer dough from mineral interactions with the flour proteins. Yeast may act faster, since it requires minerals to grow, but the tight dough resists rising and may flow poorly. Increasing yeast, adding yeast food such as ammonium carbonate in minimal amounts and even adding a little malt or malted flour may be sufficient.
In large production operations, it may be possible to specify use of a lower protein flour in order to match the available water.
Very hard water, especially with high metal levels, can also depress the activity of yeast. In extreme cases, using a water softener can be the way to good dough. Remember, softeners remove hardness by substituting salt for the minerals, so in extreme cases you may need to adjust salt levels in the dough formula. An added advantage to a softener is easier cleanup of hard water deposits from moist proofers or coffee machines.
A very soft water can yield a slow rising and soft, weak dough. Yeast, as mentioned, needs minerals to function well. An extreme case of this would be trying to make dough from distilled water, which has essentially no minerals at all. If you’re ever stuck in this emergency situation, boosting salt to above two per cent of flour weight can help, as well as dropping water levels as much as two per cent. You’ll still see a poorer crust colour and texture, but you’ll get by with most dough types. Another useful trick is to work the dough a bit more than normal, thus developing a better gluten structure.
Another property of water important to pizza dough is the acid level – called pH. The pH scale runs from 0 to 14, with 7 being neutral. Lower numbers indicate more acidity or sourness (tomato juice is around 4, vinegar is around 2) and higher numbers, more alkaline (baking soda is around 8, ammonia water is around 12). Pure water is 7 – the ideal balance point. Most municipal water ranges from 6.5 – 8, mostly due to dissolved minerals and gases, which is the acceptable range for dough.
Overly alkaline acidic water can occur, and will slow yeast activity. If slower proofing is a problem, adding a touch of vinegar, cream of tartar or sour dough concentrate can bring the pH into the optimal range. Some yeast is less sensitive to alkalinity, and switching to one may reduce the need for other additives. Excessively acidic water is rare, but in a few cases may occur in wells or other surface sources. Adding a little bicarbonate of soda, or even alkali corn masa flour can improve dough using such water.
Water amount and temperature control dough consistency and temperature. By changing the amount, we can make dough stiffer or slacker. Typical levels vary with flour type and source, but a strong Canadian hard flour will typically require at least 65 parts water by weight water added to every 100 parts flour. Such a measurement is termed “65 baker’s per cent,” meaning 65 per cent “to the flour.”
Water levels to some degree determine whether a crisper or softer baked crust is produced, as water combines with wheat proteins to form the gluten, which is basic for all flour dough-based products. Baking sets this gluten, and the set gluten character contributes to crispness. It is useful to note that added oil or shortening is also a key factor.
Water also acts as the solvent for those dough components that dissolve, including salt, sugar, and similar items. For all ingredients, it acts as the lubricant for dispersing them. Finally, during the bake, water swells the starch in the process of gelatinization. This swelling of starch, along with heat coagulation of the water-dependent gluten, gives the basic structure to any crust.
Water temperature should be carefully controlled to ensure the desired end product. Typical finished dough temperatures are 20-25ºC. A cold dough can fail to develop adequately, requiring overly long mix times. Excessive warmth can lead to reduced yeast viability, and excessively soft and flowable dough, which may not proof correctly, leading to collapse under store conditions.
Controlling dough temperature by water temperature is a useful tool, and opens the possibility of varying the amount of mixing of dough to give specific crust characteristics without requiring a traditional long mix to bring the dough to temperature through mechanical warming. Recording the water and dough temperatures is always useful when looking for dough consistency, or in experimenting with alternate crust styles.
Of course, any water-containing liquid, such as beer, buttermilk or even soda water can serve in dough making, and indeed even bring some unique advantages. Adding beer to dough water can soften and condition a tough crust; the acid in buttermilk can help ensure a great, rich-tasting crust even in high-alkaline water areas.
Some pizzerias, like some bakeries, make great stock of using spring water – and that can provide a consistent, clean water source year in and year out. Feel free to experiment – how about a little apple juice in your dough to add a slightly fresh and tart note? Just keep in mind mineral content and pH of any partial or complete water replacement, and apply a little science to the art of pizza!•