Low foam production: The foam that accumulates on top of your juice is a good indicator of how much air has been whipped into your juice by the machine, and more air exposure equals more oxidation. Oxidation is a controversial topic. As Harold McGee explains in On Food and Cooking: The Science and Lore of the Kitchen, “Because juicing mixes together the contents of living cells, including active enzymes and various reactive and oxygen-sensitive substances, fresh juices are unstable and change rapidly.” So the prevailing theory among juicers is that if less oxygen is whipped into a juice, the valuable nutrients and enzymes remain more intact. But as Kohler told us, there’s not much peer-reviewed research on how or if oxidation affects the nutrient contents of your juice. “It’s all manufacturers’ data for the most part,” he said, “which I take with a grain of salt.” That said, we still prioritized machines that produced less foam, because at the very least, oxidation can cause your green juice to turn brown, and may lead to some muddy, off flavors.
Centrifugal: This is the most common type of juicer sold at kitchen stores and big box retailers. It’s the most affordable. Once you feed in the vegetables or fruit, it shreds and spins very fast so that the pulp and bits of fruit and vegetables are caught by a strainer or filter and the juice spins out. Centrifugal juicers can be loud. And, because they are fast, they heat up, which can affect the nutritional value of the juice.
If a significant portion of your calories are going to come from juice each day, mix up your produce. Go with veggie-heavy juices, using just a bit of fruit for sweetness. Alternate types of produce, and try something entirely new periodically. Farmers markets and ethnic grocery stores are great spots to find fruits and vegetables you’ve never tasted before.
Another important consideration is where you plan to store your juicer and how easily you’ll want to access it. While horizontal-masticating juicers can churn out high volumes of juice, you may not have space for them. Plus, they tend to weigh more so tend to be difficult to move from closet to counter. The small footprint of vertical juicers is ideal for smaller kitchens with limited counter space and can often tuck under cabinets. Lightweight centrifugal models are perfect if you need to move your juicer from storage space to counter. Just make sure whatever model you pick can handle the volume of juice you plan to make: smaller juicers equal smaller amounts of juice per batch.