Cooking for Geeks: Real Science, Great Hacks, and Good Food (44 page)

Hops — the flowers of a herbaceous perennial — are a recent addition to beer making. The earliest beers were flatter and sweeter, and would quickly spoil. Around the eighth century, brewers discovered adding hops extended storage times by acting as a preservative.

Making your own homebrew doesn’t have to be a long, drawn-out process. You can make your own soda with just a few minutes of work, and it’s rewarding to see the curtain pulled back on an everyday drink, as the following recipe illustrates.

Start with an empty two-liter soda bottle. Add water, sugar, yeast, and flavorings, let it set at room temp for two days to give the yeast a chance to do its thing, and you’ll have soda.

Create a ginger syrup by bringing to a boil and simmering for at least 15 minutes:

Strain simple syrup to remove ginger pieces and transfer into a two-liter soda bottle. Add:

Screw on lid, shake to combine, let rest at room temperature for two days, and then transfer to fridge and drink.

Notes

You’ve just added starter yeast to bread dough or a liquid such as wort (beer liquid before it’s beer). What happens next?

While each yeast cell goes through these stages, different cells can be in different stages at the same time. That is, some cells can be reproducing while others are respiring or fermenting.

The recipes in this chapter assume that you are using instant yeast. Check in the refrigerated section of your grocery store: SAF Instant and Red Star are two of the more common brands.

If you have active dry yeast instead, you will need to proof it first. Proofing — soaking in lukewarm water — softens the hard shell around the active dry yeast granules. Use lukewarm water (105°F / 40°C). If the water is below 100°F / 38°C, an amino acid called glutathione will leak out from the cell walls and make your dough sticky; if it’s above 120°F / 49°C, the yeast will show very little activity.

Don’t be worried about too-hot tap water killing your yeast. Yeast actually dies somewhere above 131°F / 55°C, so too-hot water from the tap shouldn’t be able to kill the yeast; it just slows down reproduction. You can confirm this by filling a glass with your hottest tap water, dumping in some yeast, waiting a few minutes to give the yeast time to come up to temperature, and then adding some flour and watching the yeast still do its thing.

You can skip all this proofing and temperature stuff by just using instant yeast.

In baking,
proofing
can refer to a few different things: checking that your yeast is alive, allowing the dough to rise, or allowing the shaped loaf to rest and rise before baking.

Whatever you call it, you should make sure that your yeast is alive before proceeding to work with it. Measure out 2 teaspoons (10g) of the yeast and 1 teaspoon (5g) of sugar into a glass and add ½ cup (120g) of lukewarm water (105°F / 40°C). Stir and let rest for two to three minutes.

You should see small bubbles forming on the surface. If you don’t, your yeast is dead — time to head to the store.

You probably don’t need to check your yeast every time you use it, especially if you’re using instant yeast and storing it in your fridge. If you notice that your doughs aren’t rising as expected, though, give the yeast a quick check.

Proofed yeast will bubble up and foam (left); dead yeast will separate out and not foam (right).

If you’ve never made bread before, a simple loaf is easy enough to make, and perfecting it will keep you busy for many years. This is one of those recipes that’s worth making several days in a row, making one change at a time to understand how your changes impact the final loaf.

In a large bowl, whisk to thoroughly combine:

Add:

Stir just to incorporate — maybe 10 strokes with a spoon — and allow to rest for 20 to 30 minutes, during which the flour will absorb the water (called
autolysing
).

After the dough has undergone autolysis, knead it. You can do this against a cutting board, pressing down on the dough with the palm of your hand, pushing it away from yourself, and then folding it back up on top of itself, rotating the ball every few times. I sometimes just hold the dough in my hands and work it, stretching it and folding it, but this is probably unorthodox. Continue kneading the dough until it passes the “stretch test”: tear off a small piece of the dough and stretch it. It shouldn’t tear; if it does, continue kneading.

Form the dough into a ball and let it rest in the large bowl, covered with plastic wrap (spray it with nonstick spray to avoid it sticking), until it doubles in size, normally about 4 to 6 hours. Try to store the dough someplace where the temperature is between 72°F / 22°C and 80°F / 26.5°C. If the dough is kept too warm — say, if you’re in a hot climate, or it’s too close to a heating vent — it will double in size more quickly, so keep an eye on it and use common sense. Warmer — and thus faster — isn’t necessarily better, though: longer rest times will allow for better flavor development.

After the dough has risen, give it a quick second kneading — more of a quick massage to work out any large gas bubbles — and form it into a tight ball. Coat it with a light dusting of flour, place it on a pizza peel (or piece of cardboard), cover it with plastic wrap again, and allow it to rest for another hour or two.

While waiting for the dough to proof, place either a pizza stone or a baking stone in your oven and set it to 425°F / 220°C. (No pizza stone? Use a cast iron griddle or cast iron pan, flipped upside down.) Make sure that the oven is fully heated before baking — a full hour of preheating is not unreasonable.

Just before transferring the dough to the oven, pour a cup or two of boiling water into a baking pan or cookie sheet and set it on a shelf below the baking stone. (Use an old cookie sheet; the water may leave a hard-to-clean residue on it.) Alternatively, you can use a spray bottle to squirt the inside of the oven a dozen or so times to increase the humidity. (Be careful not to hit the light bulb inside: it can shatter.) Upping the humidity will help impart heat into the bread faster and will also prevent the outside of the loaf from setting prematurely, giving the bread better
oven spring
— the rise that occurs as the loaf heats up in the oven before the outside of the loaf sets and becomes, essentially, an exoskeleton.

With a serrated knife, lightly slash the top of the loaf with an “X” and then place it into the oven. Bake until the crust is golden brown and the loaf gives a hollow sound when rapped on the bottom with your knuckles, about 30 minutes. You can also check for doneness using an instant-read thermometer; the internal temperature should be above 205°F / 96°C and ideally around 210°F / 98.5°C, which is the temperature at which starches in flour break down (see
Making gels: Starches
in
Chapter 6
for more about starch gelatinization).

Allow the bread to cool for at least 30 minutes or so before slicing; it needs to cool sufficiently for the starches to gelatinize and set.

Notes

Baker’s yeast contains a number of enzymes, one of which, zymase, converts simple sugars (dextrose and fructose) into carbon dioxide and alcohol. It’s this enzyme that gives yeast its rising capabilities. Zymase doesn’t break down lactose sugars, though, so doughs and batters made with milk will end up tasting sweeter. This is why some bread recipes call for milk and why foods like yeast waffles come out with a rich, sweet flavor.

At least two hours in advance, but preferably the night before, measure out and whisk together:

Cover and store at room temperature. Make sure to use a large bowl or container with enough headspace to allow the batter to rise.

Briefly stir the batter and then bake in your waffle iron per instructions of your waffle iron manufacturer.

Notes