Cut off the top of the plastic, 2-liter soda bottle where the sloping “shoulders” meet the straight sides. Discard the top. Place 2-1/2 lbs. sliced or shredded cabbage and 1-1/2 Tbsp. salt in a large bowl. Mix it all up really well (use your clean hands to do this). Let the cabbage stand until it is limp, about 15–30 minutes. Pack cabbage into the soda bottle, using a water-filled jar to press the cabbage down firmly. Leave at least 2 inches of space below the rim of the bottle. Place the soda bottle in a cool location (a basement or closet that stays around 60–70 degrees F. would be perfect). Place the water-filled jar on top of the cabbage to keep it weighted down. Press the cabbage down a few times over the course of the next several hours—this will release liquid from the cabbage. The liquid must cover the cabbage. If it does not, then press the cabbage more to release more liquid, or remove some of the cabbage. The cabbage will begin to ferment in a day or two; you’ll know it’s happening when bubbles begin to form. The bubbles will slow down eventually. A scum or mold might form on the top of the cabbage during this time. Don’t worry about this! Simply remove the scum with a spoon every other day or so, or when the cabbage is fully fermented. The fermentation takes about 14 days, give or take several days. You can taste the sauerkraut once in a while—dig a little out from beneath the liquid. Notice how the flavor changes as more days pass. The sauerkraut is ready when it tastes the way you like it. So, if you like it a little tart, you can let it ferment for fewer days. If you like it very tart, let it ferment longer. Sauerkraut can be eaten right from the crock, but some people simmer it in a pot on the stove for a short while first. (For some dishes, kraut can also be cooked for a long, long time, as in a slow cooker with onion, sausage, and apples. The long cooking changes the flavor of the kraut, sweetening it and letting it absorb the flavor of the other ingredients.) Sauerkraut can also be refrigerated or frozen. Makes 8 servings.