WEEK
11
Goddisgoode

I beg you . . . to bear in mind that my observations and opinions are only the result of my own impulse and curiosity and that there are in this town no amateurs who, like me, dabble in this art.
—Antoni van Leeuwenhoek, letter to the Royal Society, 1673

Weight: 199 pounds
Bread bookshelf weight: 18 pounds

“Anne, can you bring home your microscope for the weekend?”

She just stared at me, unblinking.

“What’s the problem?” I asked. “I’ll be careful with it.” Anne is a physician of the old-fashioned sort who still looks at slides (of what, I’d rather not know) under a microscope and has a nice one in her Office.

“It’s not that. What do you want to look at?”

What was this all about? Oh, right, the last time I had borrowed her microscope was twenty years earlier. Exactly. How do I know that? Because Zach was now nineteen. In the second year of our marriage, after having unprotected sex, oh, five or six times with no results of the reproductive variety, I was positive I was sterile. Perhaps it was my concern about the really hot baths I love to take or some painful but temporary sports injuries down there, but I think my hypochondria was mainly the result of having had it drummed into my head since junior high school health class that only two things can happen when you have intercourse: pregnancy and disease. The third possibility, that most of the time you’d simply have some fun, was somehow never mentioned.

Thus when I spilled a little of my seed onto a microscope slide, my stomach was tied up in a knot. I really, really wanted kids. I wanted to coach Little League teams; I wanted Kennedy-style touch football games on the lawn. Yet as I peered through the lens and twisted the focus knob forward, then backward, I saw . . . nothing. My worst fears were confirmed: I was sterile. “I knew it,” I groused as I slumped into a chair. “Now what are we going to do?”

Anne peered through the microscope as she fiddled with the knobs. “Come take a look,” she said. I gloomily dragged myself back to the instrument.

Holy smokes! There were dozens, no, hundreds, no, zillions, of my little guys swimming around like mad. It looked just like the health class movies. “Let’s go!” I yelled, dragging Anne out of the kitchen and toward the bedroom. “We’re celebrating. I can make babies!”

And not long afterward, I did. Twice. (For the record, I never coached Little League and couldn’t ever interest anyone in touch football, but we had fun all the same.) This time around, once I’d explained that I simply wanted to play voyeur to a little yeast sex, Anne was relieved. The fact that I had in my lifetime asked to borrow her microscope, though, on exactly two occasions, both times involving reproduction, did not escape her attention.

Why pull out the microscope? Well, the bread baked last week in Bobolink’s brick oven had, I am sorry to report, the same lousy, dense crumb under the gorgeous (and delicious) crust. In previous weeks, the water business had been a red herring; I had decreased the amount of yeast, changed the steam, changed the oven, and changed the flour, yet my loaves were still moist and devoid of holes. Frankly I was running out of ideas.

But not curiosity. I like science and had in fact wanted to be a doctor back in the day, but a C–in organic chemistry and a major in English literature from a state university didn’t have medical schools fighting over me. According to Anne and the kids, this is the best thing that ever happened to me (and my community), and I have to concede that Anne, as an internist, speaks with some credibility on the matter.

“You would’ve hated medicine,” she reminds me every time I bring it up, careful not to say that I would’ve been a terrible doctor, though I’m sure she believes that as well.

“I can just hear you, Dad,” Zach adds. “‘Suck it up and stop whining! Next!’”

“You have no patience,” Katie invariably chimes in. “And you don’t like talking to people.”

No patience? Well, I’d show her. We were going to do a little patient science in our own kitchen laboratory this morning. “Come on, Katie,” I said in my most enthusiastic let’s-go-out-and-play voice. “We’re going to watch a little yeast sex!”

“Cool.”

“Really, dear . . .”

Since none of the previous experiments had produced gas holes, I decided to look to the yeast. After all, it’s the yeast that produces the gas that makes the holes, but that was about where my knowledge ended. I wanted to know more and even see the process in action.

I wasn’t alone in not knowing much about yeast. For roughly fifty-nine of the sixty or so centuries that bakers have been making bread, they did so without knowing what yeast even was—not just how it worked, but even what it was. It wasn’t until the eve of the Civil War, after the invention of the steam engine, photography, and even vaccination, nearly a full century after the discovery that plants convert carbon dioxide into oxygen, that we figured out what makes bread rise. For much of that time, baking was an act of faith—faith that the dough would rise, provided you added a little of yesterday’s dough to today’s.

The word yeast first appears in Middle English before the year 1000 and is derived, suitably enough, from the German word for foam (a vestige, no doubt, of Oktoberfests of yore). But no one really knew what yeast was, and certainly no one had a clue as to why it made beer and wine ferment and bread rise, let alone suspected it was a microorganism (naturally; the very concept of microorganisms hadn’t been discovered yet). To some, the action of yeast seemed downright mystical, even proof of the divine. The 1468 Brewers Book of Norwich refers to yeast as “goddisgoode” because it was made by the blessing of God.

That wasn’t good enough for Antoni van Leeuwenhoek, one of those wonderfully eccentric figures who thankfully pop up throughout history to enliven dull science texts. A Dutch draper from Delft (which sounds like the opening of a limerick), Leeuwenhoek was born in the same city and year as the artist Jan Vermeer. In fact, their baptisms are recorded on the same page in the Delft baptismal register, surely making it one of the most valuable register pages in the world. Leeuwenhoek became enamored—one might say obsessed—with microscopes and the invisible world after coming across a hot new best seller that was sweeping Europe in 1665, Robert Hooke’s Micrographia. Filled with spectacular copper engravings made from Hooke’s own drawings of the miniature world as seen through his microscope, the book enthralled Europe with its details of a fly’s eye, a plant cell, and, most famously, a foldout of a louse that was four times the size of the book itself. (Contemporary Playmates can only blush with envy.)

Inspired by Hooke’s best seller, Leeuwenhoek set about making his own microscopes, even grinding his own lenses, while his drapery business seemingly ran itself. But unlike Hooke’s compound microscope, with its familiar lens tube holding an eyepiece and a second lens close to the object, Leeuwenhoek’s microscope was remarkably simple: a single lens only about a half inch in diameter, held in place by two metal plates. In appearance it resembled the magnifying glass he used to examine his draper’s cloth far more than it did a microscope. The whole thing could be concealed in the palm of his hand, yet he saw objects that were hidden to every other microscope in the world. Leeuwenhoek had an extraordinary talent for grinding lenses. In fact, his pocket microscopes—he made dozens, only a handful of which survive—with a magnification of up to 266 times, are superior to most microscopes used in university classrooms today. What other instrument from the seventeenth century can you say that about?

Leeuwenhoek (he added the “van” as an affectation at the age of fifty-two) had no scientific training whatsoever, but he was blessed with boundless curiosity and started looking at everything from rainwater to mouth scrapings under his microscopes. One of his first investigations has become a ritual experienced by millions of elementary school children: bringing pond water to the classroom and examining it under a microscope. Leeuwenhoek coined the delightful term animalcules (meaning “little animals”) for the single-celled creatures—protozoa and the like—that he discovered in the water, swimming “upwards, downwards, and round about.”

He sent colorful letters in layman’s language describing his observations of these sightless, wriggling microbes, “the most wretched creatures that I have ever seen,” to the Royal Society of London for the Improvement of Natural Knowledge (more commonly called simply the Royal Society), which is like my sending doodles of my garden to Scientific American. One can imagine the initial reception his letters must have received: a Dutch cloth merchant telling the London intelligentsia that he had discovered microorganisms and bacteria under a microscope he made in his kitchen. Leeuwenhoek might have vanished into obscurity had not Hooke, after initially failing to substantiate the draper’s wild claims of microscopic life, gone back and built a better microscope, thus becoming the second man in history to view microorganisms.

Eventually, Leeuwenhoek got around to looking at a little brewer’s yeast under his microscope.* He described seeing clusters of “globules,” as he called them, and went so far as to make a wax model to play with. He squished it with his hands, tugged it, and twisted it, trying to understand the meaning and purpose behind the structure. His letter to the Royal Academy describing his findings included these sketches:

Most likely, Leeuwenhoek’s globules were yeast cells in the process of “budding.” Yeast reproduces asexually by growing a small bud that forms into a new yeast organism before breaking off, the process of cell division called mitosis.

I figured I should be able to easily observe yeast cells in the act, and I wondered if I would see anything close to what Leeuwenhoek drew three hundred years before. With the microscope set up in the kitchen, I smeared a drop of this week’s poolish onto a glass slide and called Katie into our impromptu kitchen laboratory. Silly me. All we could see were huge particles of flour obscuring the microscopic yeast. So we stirred about a teaspoon of instant yeast into warm water to which we’d added a pinch of sugar as a nutrient. Fifteen minutes later, the mixture had turned almost creamy, frothing as small bubbles rose to the surface, and we prepared a new slide. Under the microscope, the drop of water seemed to contain a host of yeast cells, many clustered together, but at this magnification it was hard to see any detail. Yet when I moved to the highest power of the microscope, the field was too dark to see anything. I moaned to Katie.

“Let me see,” she said, nudging me out of the chair to take over the microscope just as her mother had done twenty years earlier. Katie reached under the microscope stage and turned a diaphragm I hadn’t seen, letting in more light and revealing the yeast. At high power now, several of the clusters looked similar to Leeuwenhoek’s sketches, but I couldn’t see anything that I could conclusively say was budding yeast. This was confusing. We should be seeing reproducing yeast in various forms of development. I kept searching across the field of view, moving the slide up, down, left, and right, and then I saw what I was looking for: budding yeast.

There was, however, surprisingly little of this budding going on. We prepared a few more slides but still couldn’t find much evidence. This bothered me. Had I overestimated the amount of reproduction taking place? But if the yeast wasn’t reproducing all that much, then where did all the gas that makes the dough swell come from? Just that tiny bit of yeast originally added? And I had another question: Carbon dioxide is odorless, but there were some strong, pungent smells coming out of that bubbling yeast. I wondered exactly what was going on in there.

As did Leeuwenhoek. Aside from the budding, something else puzzled him: “I saw a great number of gaseous bubbles rising from a blackish particle which was a thousand times smaller than a grain of sand,” he wrote, “but in spite of all my pains I was unable to arrive at their cause.”

In fact, it would be nearly two centuries before anyone would “arrive at their cause,” and it would happen almost by accident. In 1854 a young chemist named Louis Pasteur took a position at the new Faculty of Sciences in Lille, in northern France. This industrial city, home to a number of sugar beet distilleries, had recently underwritten the school in hopes of training its young men in practical industrial applications of science. Pasteur, though, seemed ill suited for that role, needing to be reminded by his dean to make sure his “applications adapt themselves to the real needs of the country.”

Pasteur griped about this privately but descended from his ivory tower long enough to help the father of one of his students, a distiller who was having a problem. A number of M. Bigo’s sugar beet vats were sick; rather than fermenting into alcohol, they were going sour. When Pasteur examined the contents of the healthy vats under his microscope, he saw, as expected, many yeast cells. But in the sick vats, the yeast was being crowded out by something else—microorganisms far smaller than yeast cells and shaped like long rods.

Bacteria.