I often have Hollandaise left over which I’d like to re-use.
I’m using the sous vide method to cook the egg at 65 deg for 30 min (Modernist - at home) then I transfer the final sauce to a creaming siphon and it goes back into the sous vide at 55 deg for 1-2 hours.
Given the egg has been cooked and pasteurised and it’s basically a mayonnaise, how long should it last in the fridge?
Helen, cooking from MCAH can be a challenge, good for you.
Hollandaise is one of the sauces that doesn’t take kindly to reheating.
The mass of the siphon helps maintain temperature, but consider It also resists cooling to a safe temperature.
For just myself i would never keep any similar sauce longer than 72-hours, and only if the formula contains a substantial amount of salt and acid. If serving others, i wouldn’t risk keeping it.
Does Myhrvold provide any guidance on keeping it, and if so, in the siphon?
I wouldn’t, they are difficult enough to clean.
MCAH is awesome isn’t it?
Hollandaise…
Re-heating in a microwave at 20% power until it’s warmed works for me.
And the Hollandaise recipe in MCAH has as a lot of salt and citric acid.
I also realise that if I didn’t empty the Whipper into a container it would clog-up like cement.
Chatnoir,
I like Robert L Wolke for my foodige science.+ MCAH, et al.
But mate. “consider it also resists cooling to a safe temperature.” ?
What?
Hi @HMR
I believe the comment “resists cooling to a safe temperature” simply refers to the fact that you also need to cool the siphon as well as the food itself. Takes a lot more to cool both siphon and food that it does just the food. Good old Thermodynamics at work! 
HMR, please pardon my poke in the eye.
My replies here are usually meant to impart some thoughtful awareness of what’s happening to Community members’ food while it’s cooking or not.
You know, - how some folks are blissfully unaware of concepts such as food safety and how mass matters when it comes to energy in or energy out in case someone is considering chilling something in a siphon.
That’s all.
And Mirozen always gets it.
I am also interested to know about this. Thanks for updates.
Cheers! Thanks for getting back to me.
Food poisoning is unappealing and it’s why I’ve put it out there. I was at boarding school…
“Resists cooling to a safe temperature” had me thrown though. I apologize if my response seemed a touch ungracious.
Anyway, so I’ve scraped the still warm Hollandaise from the siphon into a plastic container and put it in the fridge. Usually there’s only about 100ml leftover Hollandaise (don’t scoff, it’s enough to put on a Benedict), The fridge is at 2 deg and I’m not too worried about it (100 ml) adversely effecting the temperature of the surrounding food.
So, if the egg has been cooked at 65 deg for 30 min and then gets 2 hours more at 55 deg. It’s got salt and Citric Acid. Does that count as pasturised?
My BIG question is: “does anyone actually know how long you can safely keep it in the fridge?”.
PS. But you could have just said "are you reducing the kinetic action of molecules in the bounding material faster than the perversely thermal properties of the foam - by using nitrogen? ", and I would have been right there.
Chatnoir
Food safety should be compulsory at school. Basics are one lesson. Please don’t think food safety wasn’t foremost in my mind.
But effective communication is important too.
I’m just saying;:
… “consider it also resists cooling to a safe temperature”
might be better put as, (and I’m still not 100% sure)
… "consider that the siphon will stay warm, which may adversely heat food in your fridge and allow pathogens to develop.
Scrape sauce from the siphon into a container and place in fridge"
Cheers H
HMR, i thought it hard to believe anyone cooking at your level would refrigerate a warm siphon. However, I’ve always found it better to focus on thoroughly chilling the food first. Then i don’t have to wonder how many hours newly refrigerated food is in the danger zone.
In my experience there’s too many variables to have one ultimate length of cold holding time for the home cook. It concerns me how often Anova users cite Baldwin’s " . . . for up to 90 days," which strikes me as potentially dangerous if not done in an extremely well regulated kitchen.
Most public heath agencies mandate a 72-hours-and-out rule and look for proof of compliance by labeling and dating. That’s always been good enough to keep me problem free.
You ask about your technique of Pasteurization. A two stage cook puts the necessary mathematical calculation well beyond my level of competency, but it appears safe particularly considering the probable low pH of the sauce. I would still adhere to 72-and-out.
Thanks mate, I’ll go with 72 hours until more information is available.
PS. I’m with you on Baldwins. Anyone got a petri dish? Yerkk.
Baldwin’s extended storage times depends on proper pasteurisation, complete rapid chilling in a sufficiently iced bath and storage at he correct temperature in a fridge with an accurate and efficient thermostat. It’s a process chain that most home setups are not up to.
Now I’m curious. Would Baldwin know how long a Hollandaise lasts?
But, thanks, I shall check out this Baldwin cove 
Just had a look at Baldwin.
Referencing his chicken pasteurisation guide for a 7D reduction in Salmonella (using this guide because it specs Salmonella).
An egg (which contains about 10% fat) cooked at 65 deg for 6 minutes should be pasteurised. 30 minutes should nail just about everything. Plus the 2 hours at 55 deg.
But it looks like 72 hours is still the best guide.
I have a mea culpa. I suspect I was conflating ‘pasteurisation’ with ‘sterilisation’.
(NB. if anyone else is reading this; pasteurisation ensures the fresh food you eat is safe, sterilisation is what they do to the food they send to the space station. Fresh food does not automatically equal safe food.)
But the most definitive advice I’ve been able to find from Baldwin is:
Pasteurized food should be served immediately or stored below 3°C (37°F) and consumed or chilled/refrigerated within a specified time period.
Helpful.