Jarlsberger

[Gustav]

I'm intererested in making A jarlsberg tomorrow & think I will definately use this recipe that is on the forum. I just want to make sure of one thing... Sodium nitrate is the same thing as salt peter isn't it? The stuff one use to make gunpowder?  What specific role does it play in the cheese?

What is the role of the propionic bacteria?

[Sailor Con Queso]

Sodium Nitrate (Saltpeter) has traditionally been added to cheeses, especially Dutch types, to eliminate late gassing from unwanted colifrorm and Clostridium bacteria. The actual inhibitor is Nitrite reduced from the Nitrate

Propionic bacteria produce propionic acid - Swiss flavor.

[Gustav]

Thnx. I just placed my order for some.

[DeejayDebi]

Probably a bit late for this but I made the recipe with and without the nitrates and saw no difference.

[Boofer]

Yeah, I'm late too.

I have also tried sodium nitrate following Debi's recipe in combination with information from the Norwegian study.

Here's some info from the study on nitrate usage:

"Addition of nitrate is a well-known technical aid in cheesemaking to avoid butyric acid fermentation. Butyric acid fermentation in cheese is due to the growth of spore-forming bacteria in the genus Clostridium, so-called butyric acid bacteria, and the species Clostridium tyrobutyricum is the most common in cheese. Growth of such bacteria in cheese can render it totally inedible, mainly because large amounts of butyric acid are formed. In addition, so much hydrogen is produced that the cheese structure is destroyed. Unlike CO2, hydrogen is not soluble in the cheese moisture and large holes and cracks are produced in the cheese. The effect of adding nitrate to the cheese milk was dependent on the presence of butyric acid bacteria in the milk and the potential for them to develop in the cheese."

I concluded that the possibility of encountering butyric acid bacteria in the milk I buy was fairly low so I decided not to use it any more.

-Boofer-