The Cellar - Blueberry Spread

Today I Learned. Good one James and Ali.

It turns out that salt and sugar both work the same way:

http://www.answers.com/Q/Explain_the...d_preservation

Quote:

High-salt and high-sugar mixtures preserve food because they are absorbent relative to the internal fluid of microorganisms, causing them to shrivel up and eventually die. When a layer of a high-salt or high-sugar substance is used to preserve food, the food is protected from microbial invasions. This is a more sophisticated way to preserve food than the oldest method - simply letting it dry out. With salt and sugar, one can theoretically preserve food for decades without it being consumed by bacteria. The value of a method to reliably preserve food can hardly be understated. Prior to refrigeration, which is only about a century old, a preserve was the only way that an autumn harvest could be stored throughout harsh winters.

The deeper explanation:

http://sciencefocus.com/qa/how-does-...t-preservative

Quote:

Bacteria evolved in environments where the concentration of sugars and salts is the same as or lower than those inside the cell. High sugar concentrations cause the bacterium to lose water by osmosis and it doesn’t have any cellular machinery to pump it back in against the osmotic gradient. Without enough water, the bacteria can’t grow or divide. Mould is more tolerant though and can grow on some jams.

It's life, Jim, but not as we know it.