For maximum botulism-killing effect, can curing salt be added to boiling water when making a brine, or should the brine be cooled before adding the sodium nitrite? Bonus points for citing sources.
Brines with curing salt are made similarly to other brines except that the curing salt must be stirred into the brine after it has cooled to room temperature. It cannot be added to hot or warm brine because heat lessens its effectiveness.
Heck of a first post!I think it is a very good idea to NOT BOIL your pink salt or prague powder. The chemistry of meat cures is not terribly complex and it goes like this. Nitrate ions can be reduced to nitrite ion by fermentation bugs over time. The nitrite can be further reduced to nitric oxides which DO THE CURING by reacting with meat proteins like myoglobins to create the pick color. Using just a small amount of very reactive nitrite allows the cure to be much safer as the extra abundance of nitrate is not needed when using an insta cure made with nitrite. BUT nitrite can be oxidized back to nitrate so you want there to be enough to get the job done without exhausting them to zero before the cure completes. A reason to boil your salt, sugar brine is definitely to kill off as much bacteria and fungi as possible. Yes the spores can survive this boiling but only spores can survive boiling for any length of time including the tough to kill C, botulism spores. That is why canned foods with low acidity have added acids (green chilis etc) to keep the C. botulism from growing in the low acid media. Same for meat cures. Unless it ferments to make it a sour dry ferment, the added nitrites kills off the C. botulism bacteria that somehow survived as spores.
So Nitrates are very stable in solution and do not degrade from boiling although nitrates can be leached from meats and veg by boiling in water so the levels go down iin the meat or veg f you don't eat or drink the boiling liquids. Nitrites are less stable in solution and capable of being oxidized OR reduced. Reduction to nitric oxide in solution is the desired step to effect a meat cure but nitric oxide is REALLY UNSTABLE in liquids or as a gas. It is a super reactive short lived species (it will react with many molecules including proteins and fats) and also volatile so until it reacts with the meat it can also just outgas into the air or volatilize away as it is also a gas and a big component of smog etc.
Boiling the water kills good and bad bugs but not the spores from bugs quickly AND it helps dissolve the salts and sugar. Boil salts and sugar and then let it cool and THEN ADD your prague powder or instacure. The less nitrite you are using, the more important that the small amount used is really there and active. Commercial cures often require the use of sodium erythorbate which is a preservative on it's own and safe but ALSO acts a reducing agent to help reduce the small amount of nitrite to the super active nitric oxide curing species. So if you are using a ton of instacure or a mix of nitrite AND extra nitrate for a long cure, it doesn't much matter if you boil it first as you have a huge and unhealthy excess of nitrate to act as a reservoir but that isn't considered healthy or safe and may exceed FDA approved levels for nitrate. GO low nitrite without extra nitrate and be much more careful and still get a good safe cure is the way to go.
Very cool.I searched and found that this was the one board that even mentioned this topic. So I posted a reply as I am a chemist working in biotech for way way too many years and have too many technical books on fermentation science, brewing, wine making and meat smoking / curing / fermentation. This is just an overlooked part of making your meat brines. The history of meat brines and cures is fun stuff and over time here in the US, the levels of nitrite just keep going down as excess free nitrites are bad for our health. But of course no nitrites can ALSO be very bad for our health if the meat has C. botulism toxins in it. Yet in Europe and Asia, there are many large cuts of meat safely preserved without ANY nitrites at all. Spanish jamon, Chinese Yunnan hams and many more. Tons of Italian charcuterie are made with salt as the basc cure and they know how to do it safely.