What Preservatives Do
A preservative exists to stop biological processes — mostly microbial growth, sometimes enzymatic browning, sometimes oxidation. Every common one works by one of three mechanisms:
Lowering pH (citric acid, acetic acid). Bacteria need a roughly neutral environment; acid keeps them from establishing.
Directly inhibiting microbes (sodium benzoate, potassium sorbate, sulphites). These interfere with specific bacterial metabolism.
Blocking oxidation (ascorbic acid used as preservative, BHT, BHA). These donate electrons to reactive oxygen species before those species damage the product.
Which Ones Are Genuinely Fine
- Citric acid — present in every lemon. Added to industrial foods in the same form. No meaningful health concern at food-level doses.
- Ascorbic acid (Vitamin C) — identical to the vitamin in fruit. Also a preservative. No concern.
- Salt — the oldest preservative. Pickling, curing, fermentation all rely on it.
Which Ones Are Worth Avoiding Daily
- Sodium benzoate + Vitamin C — benign on their own. Mixed with ascorbic acid, benzoate can form small amounts of benzene (a known carcinogen) under heat or light. Common in industrial juice.
- Potassium sorbate — generally safe in moderation; some evidence of gut-microbiome disruption at high daily intake.
- Sulphites (SO₂, sodium metabisulphite) — triggers asthmatic reactions in sensitive people. Common in dried fruit, wine, some packaged juices.
Why We Don't Use Any Of Them
Not because any single preservative is dangerous at reasonable doses. Because the whole point of a cold-pressed juice is that you're drinking something still biologically active. The enzymes, vitamins, and phytonutrients you're paying for are kept alive by the absence of the very thing a preservative is designed to stop. Preserving cold-pressed juice is, technically, the opposite of the product you wanted.
The honest alternative — and it's the one we chose — is short shelf life, daily delivery, and no preservatives. The cost is that the system has to deliver every morning. The benefit is that what you drink is what was pressed a few hours earlier.