Kosher for Passover means avoiding fermentation of grains

 

There are different interpretations of the religious laws, but in general they do not allow wheat or other traditional grains, including grain alcohol, during Passover with one exception:

Wheat flour that is used to make matzos has been specially supervised from harvest through processing to ensure that it has not had an opportunity to start fermenting, so it is continually inspected to ensure that it is not in contact with moisture in order to inhibit fermentation. The water used to make matzos is left out overnight to cool, also in order to inhibit fermentation. Milling, mixing with water, kneading, and baking are done in separate areas to avoid cross-contamination. 

Fermentation is believed to occur about 18 minutes after a grain is mixed with moisture, so after mixing the flour with water, kosher for Passover matzos are put in the oven within that time limit; the ovens are separate from the preparation areas so that the heat is not promoting fermentation of materials being mixed/prepared.

Grain-based fermentation products such as alcohol are also forbidden in kosher for Passover products, since the purpose is to avoid using aged or fermented materials to mimic the plight of fleeing slaves who didn't have time to let (sourdough) bread rise in their hurry to flee Egypt. 

(While it is quite likely that the newly freed slaves would have grabbed already-baked bread, this specific kosher for Passover practice of removing all leavened bread and other forbidden items from a household during the holiday is evidently intended as a ritual to evoke sympathy for their hurried exodus during the Passover Seders practiced by their descendants.)

The traditional grains banned unless following the same rules as the matzo wheat include wheat, rye, barley, oats, and spelt; all of which were available in Egypt some 3,500 years ago. 

Wine is allowed for Passover when the yeast is the product of the grapes themselves. But the wine must not include added non-kosher yeasts, other non-kosher additives (isinglass), or be produced/stored in a room containing grains or products made from grains. The work must also stop on the Sabbath, so observant Jews must be the winemakers. 

Gluten issues, allergies vs sensitivities vs digestive issues

All grains contain gluten; some forms are just more allergenic or more difficult to process than others, which can vary from individual to individual. Wheat is the most common gluten reaction; which is also possible for rye, oats, barley and buckwheat. Some people are sensitive to certain proteins because of leaky gut, a condition where digestion is impaired because of GI tract disorders. Non-allergenic "delayed sensitivity reactions" to proteins may be caused by leaky gut and the specific immune cells reacting to these specific proteins can be reprogrammed to be non-reactive to them by completely avoiding these specific foods for at least 6 weeks. Not so for true food allergies, which can be permanent and trigger ever-increasing reactions with every occasional exposure. People's abilities to digest proteins vary with genetics, immune system capacity and probiotics present in the gut. There is even current research on specific bacteria that prevent the damage caused by wheat in susceptible people's guts. Only about 1% of the population tests as truly allergic to wheat protein, between 1-2% for dairy protein. Obviously, many more are (temporarily) sensitive to these proteins based on gut dysbiosis and leaky gut tissues failing to completely digest these foods. The issue of lactose intolerance is another possible cause of gas or bloating after consuming non-fermented dairy products (except for low-lactose products like whey protein isolate). The use of antacids is a major factor reducing digestion of proteins and minerals in the stomach, as well as reducing the essential acidic barrier against pathogenic organisms that may be present in our food and water; even from dirty hands that we use to eat. Stress and improper chewing may also contribute to the presence of extra undigested proteins in the gut, composed of undigested food and undesirable microbes. Who's left to clean up the mess and try to get some badly needed nutrients into the bloodstream? The immune system, though imperfectly. A major part of immune cell counts and activity is in the GI tract for exactly this reason, consuming a lot of energy. If digestion fails and the GI tract contains an unhealthy mixture of organisms and large protein masses, the result is a significant immune challenge by every measure, leading to inflammation and fatigue. Glutamine is an amino acid present in most protein-containing foods that is essential to brain and nerve function. Magnesium, other amino acids (ie taurine) and antioxidant co-factors render it far less overexciting to neurons. MSG and aspartame are additional proteins that can cause nerve overstimulus in some circumstances. There are ways to reduce these reactions, as described thoroughly by Dr. Russell Blailock in his books, lectures and articles. The bottom line: No need for most people to avoid soy, milk or grains if they can maintain the intregrity of their digestive and GI tracts properly. Most of those whose systems aren't in such good health can utilize fairly effective means of correcting these issues and eventually resuming the use of these foods in their diets, unless they are the relatively few with true allergies.