Chamber Vacuum Sealers, 2011–2014

[Robert Jueneman]

I tried to edit my post, but it timed out.

There are two more modifications to the unit that I want to try. PolyScience was running a special on the new MVX-35XP, which is slightly larger than mine and adds a soft-fill control. In addition, it allegedly supports an external vacuum hose, so that I could use it with a FoodSaver dry goods container (perhaps instead of the gas fill option), or a hotel-pan marinating tray But when I asked Joe Stryber at PolyScience about it, he said, "yes it does -- just like your "MSV-31X". WTF ???

I went back to reread the manual, but it doesn't say anything at all about such an option. The best I can figure is that it should be possible to screw a threaded barb into the vacuum opening at the inside rear of the unit, then press a hose onto it to connect to something else, of course with the lid open. I just ran over to the hardware store to check, but unfortunately they closed early for New Years Eve. The threaded vacuum port has an interior diameter of 9 mm, but I don't have a metric thread gauge to know what size threads it uses. If anyone else knows, please respond.

Finally, I would love to have a soft-air release feature, to avoid the sudden compression at the end of the cycle. As best I understand, that would simply require putting a constricting valve in the air resupply line. It would be nice if this were accessible from outside the unit, but that might not be essential -- except maybe for compressed watermelon. Maybe in July , but probably not in January (except in the antipodal regions!) But perhaps this wouldn't be too hard to add as an option. TBD.

If I could confirm that the MVS-35XP has all of these features, along with the label printer; or maybe the larger 45XP, I might be tempted to buy one and sell my existing unit on eBay or elsewhere, but first they will have to make the user manual available.

Finally, I'd like to suggest that the single most useful accessory item for the MSV-31X or similar machines is the slanted tray with variable stop positions. I find the stack of spacers supplied with the machine to be quite awkward to use, and particularly to remove, and as a consequence I use them once in every blue moon. But the slanted tray I use every single day. Even if you don't have the MVS-31X, I would suggest that you consider this accessory, assuming it will fit in your machine.

Happy New Year, everyone! Or as they say around here. Feliz Ano Nuevo!

[Robert Jueneman]

Hmmm. Your nitrogen regulator shouldn't leak and I don't ever recall having to use Teflon tape. Been quite a while since I had a tank and regulator, but I think there should be an o-ring type seal. If it is the regulator, it's defective. I suspect your leak is elsewhere.

30 psi is quite high actually and good regulator should be able to hold that without an issue.

A soap solution test showed that the leak was around the bottle-to-regulator interface. There is no O-ring seal, but there is a sliding coupling, and that may be the problem, in which case the Teflon probably won't help. TBD.

[GlowingGhoul]

Robert, if you do decide to upgrade, have a good look at the Henkelman units.

There is a proprietary feature the Henkelman's have that simply becomes indispensable once you've used it: Vacuum by H20 sensor (instead of time or pressure, though it does that as well). This applies the maximum vacuum to meats and liquids but stops just at the boiling point. Quality of meats prepared for storage and for sous vide is noticeably better than when estimating the proper vacuum level. When packaging liquids using the H20 sensor there is never a mess.

I know service is one of your concerns (and rightly so). Henkelman built and shipped my machine from the Netherlands to New York 5 days from my order. I've ordered accessories that came straight from their factory in 3 days. Shipping was always free (well, included in the price anyway).

Vacuum packaging machines use fairly straightforward technology, and with proper technical information and parts anyone who services one brand can service another. Henkelman makes both the schematics and parts easily available. They have a video on their site with an engineer talking about how they keep every replacement part in stock for immediate shipping and how, at their customers request, they've broken down expensive parts into smaller components which can be replaced individually at a much lower cost. I've been advised that in the event of a breakdown during the warranty, they will use a local restaurant equiptment servicing company to do the repairs.

[Robert Jueneman]

GlowingGhoul (what a moniker!), thanks for all of your useful posts on this subject.

It's true, I was somewhat concerned about availability and service of the Henkelman units here in the US, vs. the Minipack MVS-31X sold by PolyScience and Doug Care, among others. But when I ordered the gas fill adapter, it took almost 6 weeks to be delivered -- hardly exemplary. Apparently the Italian factory was closed for their extended vacation at the time.

I'm not entirely convinced about the necessity of the H20 sensor, although it seems like a nice feature. I haven't had a problem with 99% for most meat, for example, and I tend to chill any liquids that need to be packaged.

However, I would be most interested if you or anyone else could provide concrete, organoleptic blind taste tests to confirm the quality of meats prepared using the H20 sensor vs. say 99% vacuum?

Bob

[GlowingGhoul]

Although it doesn't appear that there's been any scientific study of the subject, you can easily demonstrate the drying effect of applying too high a vacuum to meat.

Thoroughly dry a piece of red meat, then seal it at 99% vacuum.

Watch the meat carefully as vacuum is applied, and, depending on temperature (but certainly by 96%), you'll see liquid boiling out of the meat.

Although the colder the meat is the lesser the effect, this will occur even if near frozen.

Open the package, and your once dry meat is now soaking wet with liquid on the surface. Leave it in the package for several hours, and the quantity of liquid removed from the meat will be much higher.

In the meat packaging industry, this is known as "drip loss" (though drip loss can be caused by other factors as well as vacuum). This is controlled by meat packers vacuuming to a lower percentage then heat shrinking the bags make them skin tight, rather than using very high vacuum. Freeze drying uses vacuum to intentionally accomplish the same effect, but to a much higher degree of course.

Most of the time, the H20 sensor stops vacuum at between 84% and 92%, before any boil off is visible.

Simply lowering the vacuum to 85% would probably avoid this problem in most cases, but because I do a lot of long cooks where the bag has a tendency to puff up (due to phase change) I like being able to maximize vacuum to keep the bag as tight as possible.

Other changes happen to meat in high vacuum as well. Large pores develop, changing the structure and texture of the meat (for the worse or better I'm not certain yet). There are food industry studies on line documenting this pore development effect.

For storage I want to keep the meat and it's liquids intact as far as possible, but...

I am experimenting with beef brisket at the moment, intentionally removing moisture post smoking at 99% vacuum (controlled by varying the "hold time" after 99% is reached), then opening the bag, pouring out the liquid, drying the meat, and rebagging for sous vide. Thus far I've found the beef flavor intensified, texture improved (in the traditional BBQ brisket falling apart sense), but required cooking time increased by 10% or so (lower heat conductivity within the meat perhaps?).

Buy a chamber vacuum, become a mad kitchen scientist

Edited January 1, 2012 by GlowingGhoul (log)

[mgaretz]

Hmmm. Your nitrogen regulator shouldn't leak and I don't ever recall having to use Teflon tape. Been quite a while since I had a tank and regulator, but I think there should be an o-ring type seal. If it is the regulator, it's defective. I suspect your leak is elsewhere.

30 psi is quite high actually and good regulator should be able to hold that without an issue.

A soap solution test showed that the leak was around the bottle-to-regulator interface. There is no O-ring seal, but there is a sliding coupling, and that may be the problem, in which case the Teflon probably won't help. TBD.

I'd suggest looking into getting a different model that has the o-ring seal. Here's a link to a data sheet from Taprite: http://www.taprite.com/pdfs/beer/Sentry_Nitrogen_Regulators.pdf

Taprite primarily serves the beer/wine market so their regulators are designed to be on at all times (meaning the main tank never gets shut off unless it's being replaced) and they are also designed to work at and hold a low delivery pressure. You can see in the picture there's an o-ring at the tip of the nipple. I never had one leak.

[PedroG]

Although it doesn't appear that there's been any scientific study of the subject, you can easily demonstrate the drying effect of applying too high a vacuum to meat.

Thoroughly dry a piece of red meat, then seal it at 99% vacuum.

Watch the meat carefully as vacuum is applied, and, depending on temperature (but certainly by 96%), you'll see liquid boiling out of the meat.

Although the colder the meat is the lesser the effect, this will occur even if near frozen.

Open the package, and your once dry meat is now soaking wet with liquid on the surface. Leave it in the package for several hours, and the quantity of liquid removed from the meat will be much higher.

In the meat packaging industry, this is known as "drip loss" (though drip loss can be caused by other factors as well as vacuum). This is controlled by meat packers vacuuming to a lower percentage then heat shrinking the bags make them skin tight, rather than using very high vacuum. Freeze drying uses vacuum to intentionally accomplish the same effect, but to a much higher degree of course.

Most of the time, the H20 sensor stops vacuum at between 84% and 92%, before any boil off is visible.

Simply lowering the vacuum to 85% would probably avoid this problem in most cases, but because I do a lot of long cooks where the bag has a tendency to puff up (due to phase change) I like being able to maximize vacuum to keep the bag as tight as possible.

Other changes happen to meat in high vacuum as well. Large pores develop, changing the structure and texture of the meat (for the worse or better I'm not certain yet). There are food industry studies on line documenting this pore development effect.

For storage I want to keep the meat and it's liquids intact as far as possible, but...

I am experimenting with beef brisket at the moment, intentionally removing moisture post smoking at 99% vacuum (controlled by varying the "hold time" after 99% is reached), then opening the bag, pouring out the liquid, drying the meat, and rebagging for sous vide. Thus far I've found the beef flavor intensified, texture improved (in the traditional BBQ brisket falling apart sense), but required cooking time increased by 10% or so (lower heat conductivity within the meat perhaps?).

Buy a chamber vacuum, become a mad kitchen scientist

Very interesting observation! Regarding floating bags with 85% vacuum, see "The vacuum level dilemma with chamber sealers for sous vide cooking"; did you try my suggestion?

A way out with a chamber sealer might be using a sealed bag of water to weigh down the bag to be sealed and eventually a second sealed bag of water below the bag to be sealed, thus displacing as much air as possible out of the bag before sealing.

[GlowingGhoul]

Very interesting observation! Regarding floating bags with 85% vacuum, see "The vacuum level dilemma with chamber sealers for sous vide cooking"; did you try my suggestion?

A way out with a chamber sealer might be using a sealed bag of water to weigh down the bag to be sealed and eventually a second sealed bag of water below the bag to be sealed, thus displacing as much air as possible out of the bag before sealing.

I hadn't seen that, it's certainly worth a try.

I think I'll try to use 2 nearly identical cuts, pack one at 99%, and the other using your method at 80%. I'd like to find out if there's any appreciable difference in the amount of liquid in the bags after cooking. I know that once the bag is sealed the food inside isn't under vacuum pressure any longer, so if the meat vacuumed to 99% releases a lot more liquid it must be due to something like damage to the cells or some other change to the meat caused by the initial vacuum.

It would be great if liquid loss could be controlled to the point of being able to instantly create the concentrated flavor of dry aged beef(without the benefit of additional flavor from the enzymes though). On my machine, I can add additional vacuum beyond the H20 sensor tripping point (specified in seconds of additional vacuum). This might be the key to that control.

Edited January 1, 2012 by GlowingGhoul (log)

[blackp]

Very interesting observation! Regarding floating bags with 85% vacuum, see "The vacuum level dilemma with chamber sealers for sous vide cooking"; did you try my suggestion?

A way out with a chamber sealer might be using a sealed bag of water to weigh down the bag to be sealed and eventually a second sealed bag of water below the bag to be sealed, thus displacing as much air as possible out of the bag before sealing.

I hadn't seen that, it's certainly worth a try.

I think I'll try to use 2 nearly identical cuts, pack one at 99%, and the other using your method at 80%. I'd like to find out if there's any appreciable difference in the amount of liquid in the bags after cooking. I know that once the bag is sealed the food inside isn't under vacuum pressure any longer, so if the meat vacuumed to 99% releases a lot more liquid it must be due to something like damage to the cells or some other change to the meat caused by the initial vacuum.

It would be great if liquid loss could be controlled to the point of being able to instantly create the concentrated flavor of dry aged beef(without the benefit of additional flavor from the enzymes though). On my machine, I can add additional vacuum beyond the H20 sensor tripping point (specified in seconds of additional vacuum). This might be the key to that control.

See my post immediately after Pedro's referenced here. My experiment with chicken breast showed an unmeasurable difference in final cooked dry weight between samples vacuumed at 80% and those vacuumed at 99+%.

It will be interesting to see the result of your experiment using meat. If you find a difference I will repeat my chicken experiment with steak so we can see what the exact comparable difference is.

Peter.

[pep.]

I've sent back the Boxer 35 today - it just wasn't working right. I'm now again looking for an affordable chamber vacuum option, but I want a new machine.

The Vac-Star Mini is definitely to small, but the Henkelman Jumbo Plus with the domed top might be large enough (and the 8 m3 pump will be strong enough for home use with the relatively small chamber). Of course, sensor control would be preferable (not an option with the Jumbo series and the Boxer 35 is the smallest in the Boxer series). The new Henkelman Lynx models are smaller than the Boxer series, but they don't have a port for an external vacuum container and they are even more expensive. I don't think I need a MAP option.

Has anyone got a VacStar with the SX sensor control? Or a Komet Vacuboy? I'd like to know how their controls work, as those two companies don't have their manuals online. And for the people with H2O sensors on their Henkelmans: How useful is the feature in reality? Does anyone not use it?

[GlowingGhoul]

It's too bad the Boxer didn't work out for you. I noticed that the manual states that while it can be moved with oil in it, it must be kept level. It says the pump will be damaged if the unit is tipped over with oil in it. I suspect this is what happened to yours.

The electronic sensors are useful in that they automate the process(both vacuum level and H20), but not absolutely necessary. Since you can monitor vacuum level by the gauge, you can simply observe how much time it takes to get to a certain vacuum level and adjust the program for whatever task you are doing.

The Jumbo's look like an excellent deal on a quality machine. I would recommend you get the inclined plate for liquids and cut-seal option. Having the excess flap of bag cut off is useful keeping things clean (since that part of the bag often has food particles on it), and still provides a second (albeit narrower) seal.

The new Lynx units look very slick, but it looks like all you are are getting for the premium of the Lynx 32 over a Boxer 35 is good looks, data logging for health inspections, and 20 instead of 10 programs. The Lynx 32 has a smaller chamber, a slower pump (they are using the 8m3/h vs the Boxer's 16m3/h), and a since the floor of the chamber is flush with the machine (not recessed like other machines), vacuuming liquids looks like it could be very, very messy if things go wrong.

[cookman]

And for the people with H2O sensors on their Henkelmans: How useful is the feature in reality? Does anyone not use it?

I'm trying to make my final decision on which chamber vac machine to buy. I'm also really curious to hear how important and useful these H20 sensors have been for people who have opted to buy machines that have this option. I'm assuming it makes it more of a no-brainer in terms of proper settings to have an H20 sensor, but is it that hard to figure out the proper settings once you are comfortable with your machine and the particular food you are vacuum sealing?

[blackp]

As I have said before I have a Henkelman Boxer 42 with Gas Flush, Sensor control and the Cut-Off Sealer. I do not have the H2O sensing feature.

With 20/20 hindsight if I was buying today I would get a Boxer 35 without the Gas Flush, but with Sensor Control and the H2O sensor. I would order the Cut-Off Seal option again.

My reasons are simple:

I have very rarely used the size of the Boxer 42 and it is large and very heavy (65kg or 140lb!). I keep mine in the garage, but if it was smaller it could live in the kitchen.

The gas flush feature is good, but I seldom use it. Replacing the air in a bag with inert gas is less important to my use than the ability to loosely pack soft things like bread. I can easily pack several slices of bread vacuumed to 60% and even though there is still air in the bag my ability to freeze it is just the same as if I replaced the 40% air with CO2/N2. Also there is the problem of the gas tank which is large and heavy - another reason that the machine lives in the garage.

Sensor control vs timer control is a very good feature. Timer control is a bit vague given that the size and density of the product in the chamber makes a difference to the time needed, whereas with sensor control 90% vacuum is 90% vacuum regardless of the size or density of the product.

I have no personal experience with the H2O sensor, but if it works as described it would take some of the guesswork out of packing liquids. When packing soup for instance I watch the gauge to see when boiling starts and then program the device to stop vacuuming at that percentage vacuum to pack the remaining bags. It works OK, but just being able to tell the thing to stop when the boiling starts would be better.

The combined cut-off / sealer is excellent for SV use. No food residue to get into your SV tank. It also helps to keep your freezer clean. I have never had a seal failure so using dual sealing bars seems like overkill to me and you lose the ability to simply tear off the excess bag after sealing.

Hope this is helpful,

Cheers,

Peter.

[pep.]

@BlackP: Have you got the cut-off/sealer with a combined time setting or with two separate time settings? Either way, it seems to be a very useful feature.

@all: Has anyone got or heard of the brand "Besser Vacuum"? It's an Italian company and they use Busch pumps. Their smallest machine seems to be in the sweet range size-wise and the price is also quite reasonable. However, it doesn't seem very widespread ...

[GlowingGhoul]

I've never heard of them, but they look like decent machines, and the Busch pump is a good sign.

I can't figure out if they have a vacuum sensor or are programmable by time only though.

[blackp]

@BlackP: Have you got the cut-off/sealer with a combined time setting or with two separate time settings? Either way, it seems to be a very useful

I have the cut-off sealer with a single time setting and it works fine.

[Robert Jueneman]

After considerable thought, I've ordered the new Minipack MVS-35XP from PolyScience, complete with soft air release, a 100-recipe programming feature, and a printer to record all of the important stuff. It looks like I will have to install the gas fill adapter myself, as I did with the MVS-31X. I plan to record various settings for various thicknesses of beef, chicken, lamb, and fish, so all I'll have to do is hit the button and the right setting and label will be printed out, along with the date.

I forgot to ask at the time, but I'm going to send off a note to specify the 6mm seal with cut-off bar.

The unit should arrive by next Friday, and then I'll start looking around for someone in the area who would like to buy my old one, so I don't have to bother with shipping.

I found out that the 35XP external vacuum adapter uses a 1/4" NPT threaded barb, which coincidentally is what I cobbled together for the 31X. On the 31X, only about one or two threads engage in the odd-ball (metric?) fitting they use, but it works. I wrapped some Teflon tape around the fitting on my FoodSaver vacuum hose, and now I can pull a 99% vacuum on a round FoodSaver canister. So far, at least, I haven't had any problems with the container collapsing.

I also solved the gas leak problem with my regulator. I folded a strip of Teflon tape in half and twisted it, then wrapped it between the sliding threaded doohickey and the conical end of the adapter, and in addition wrapped the threads with Teflon tape.

Neither the regulator nor the gas bottle had an O-ring. Instead there is conical fitting that mates with a conical depression inside the gas valve.

Edited January 8, 2012 by Robert Jueneman (log)

[GlowingGhoul]

After considerable thought, I've ordered the new Minipack MVS-35XP from PolyScience, complete with soft air release, a 100-recipe programming feature, and a printer to record all of the important stuff. It looks like I will have to install the gas fill adapter myself, as I did with the MVS-31X. I plan to record various settings for various thickness of beef, chicken, lamb, and fish, so all I'll have to do is hit the button and the right setting and label will be printed out, along with the date.

I forgot to ask at the time, but I'm going to send off a note to specify the 6mm seal with cut-off bar.

The unit should arrive by next Friday, and then I'll start looking around for someone in the area who would like to buy my old one, so I don't have to bother with shipping.

I found out that the 35XP external vacuum adapter uses a 1/4" NPT threaded barb, which coincidentally is what I cobbled together for the 31X. On the 31X, only about one or two threads engage in the odd-ball (metric?) fitting they use, but it works. I wrapped some Teflon tape around the fitting on my FoodSaver vacuum hose, and now I can pull a 99% vacuum on a round canister. So far, at least, I haven't had any problems with the container collapsing.

I also solve the gas leak problem with my regulator. I folded a strip of Teflon tape in half, then wrapped it between the sliding threaded doohickey and the conical end of the adapter, and in addition wrapped the treads with Teflon tape.

Neither the regulator nor the gas bottle had an O-ring. Instead there is conical fitting that mates with a conical depression inside the gas valve.

Be sure to drain the oil out of your old vacuum packer before it's transported, or the pump will be damaged if the unit tips off axis.

[Robert Jueneman]

Although it doesn't appear that there's been any scientific study of the subject, you can easily demonstrate the drying effect of applying too high a vacuum to meat.

Thoroughly dry a piece of red meat, then seal it at 99% vacuum.

Watch the meat carefully as vacuum is applied, and, depending on temperature (but certainly by 96%), you'll see liquid boiling out of the meat.

Although the colder the meat is the lesser the effect, this will occur even if near frozen.

Open the package, and your once dry meat is now soaking wet with liquid on the surface. Leave it in the package for several hours, and the quantity of liquid removed from the meat will be much higher.

In the meat packaging industry, this is known as "drip loss" (though drip loss can be caused by other factors as well as vacuum). This is controlled by meat packers vacuuming to a lower percentage then heat shrinking the bags make them skin tight, rather than using very high vacuum. Freeze drying uses vacuum to intentionally accomplish the same effect, but to a much higher degree of course.

Most of the time, the H20 sensor stops vacuum at between 84% and 92%, before any boil off is visible.

Simply lowering the vacuum to 85% would probably avoid this problem in most cases, but because I do a lot of long cooks where the bag has a tendency to puff up (due to phase change) I like being able to maximize vacuum to keep the bag as tight as possible.

Other changes happen to meat in high vacuum as well. Large pores develop, changing the structure and texture of the meat (for the worse or better I'm not certain yet). There are food industry studies on line documenting this pore development effect.

For storage I want to keep the meat and it's liquids intact as far as possible, but...

I am experimenting with beef brisket at the moment, intentionally removing moisture post smoking at 99% vacuum (controlled by varying the "hold time" after 99% is reached), then opening the bag, pouring out the liquid, drying the meat, and rebagging for sous vide. Thus far I've found the beef flavor intensified, texture improved (in the traditional BBQ brisket falling apart sense), but required cooking time increased by 10% or so (lower heat conductivity within the meat perhaps?).

Buy a chamber vacuum, become a mad kitchen scientist

There is something very strange going on here. I routinely use a 99% vacuum on rib eye steaks, etc., and I have NEVER seen the boiling effect that you (and Dave Arnold) have reported. I don't think Nathan has seen it, either. I am vacuuming beef that has generally been in the fridge, so it's down around 5C or so, maybe less, as opposed to being at room temperature.

I have calibrated my unit in accordance with the instructions, to take into account that I live at 7000 ft. But it occurs to me that perhaps BECAUSE of that fact, the meat has already been subjected to a partial vacuum, at least compared to sea level. Could that cause the difference?

Hmmh. Yesterday I packed up eight Angus rib-eye steaks, all freshly cut at the same time from the same grocery store. Seven were packaged at 99%, as I usually do, but one I set for 99% plus 30 seconds. I didn't see any visible boiling, but today when I took the package out of the freezer, I noticed some ice crystals inside the package, and the bag didn't seem tightly sealed. The others didn't show that. So perhaps there was some extra liquid extracted, if not immediately than some time later?? I didn't see any kind of a leak in the seal.

The only other explanation I can think of is that you are using a Henkleman machine and I am using the MVS-31X, and perhaps the calibration procedure is somehow different -- maybe mine isn't pulling a true 99%. Then again, blackp has a Henkleman as well, and I don't think he has seen this effect, either. Maybe we both need to boil some ice water to check the calibration better.

Or maybe there are differences in the type of beef?

[GlowingGhoul]

After selecting the wrong program (inadvertantly disabling the H20 sensor), and watching my very cold rib-eyes start to boil, I dug into this and think I may have the answer.

99% is simply too vague of a measurement to accurately determine how much negative pressure the meat is subject to, and what the resulting boiling point will be.

As far as I can tell, MVP doesn't publish the "maximum final vacuum" achievable with their units. Henkelman specifies 99.8% for the Boxer 35.

The MVP-31 uses a pump capable of drawing 7 square meters of air per hour and the Boxer 35 uses a pump capable of drawing 16 square meter of air per hour. The MVP-31 pump is 0.5 horsepower, and the Boxer 35 is 1.0 HP. Although we don't know what the MVP's final maximum vacuum is, I think it's a safe assumption that given the disparity in vacuum pump strength, the MVP is likely going to have a lower maximum final vacuum than the Boxer.

A small amount of difference in the "maximum final vacuum" will make an enormous difference in the boiling point.

To illustrate, if the MVP reaches s 99.3% final vacuum, the boiling point is 40°F. At 99.8% the boiling point is 6°F! In pounds per square inch, 99.8% excerts more than 3 times the negative pressure of 99.3%.

There are other possibilites. The MVP may be stopping vacuum earlier than the Boxer. I've noticed the Boxer overshoots the programmed vacuum percentage every time (I've learned to compensate by setting it somewhat lower than I require). Perhaps the MVP stops right at 99.0%, regardless of it's maximum vacuum capability.

These small differences in final vacuum percentage (but large differences in the strength of negative pressure applied) may also explain why some chamber vacuums don't seem to be very good at fruit/vegetable compression.

PS: Although my figure of 99.3% for the MVP was just a guess, we know that if you're not seeing boiling of non-frozen meat, the vacuum level can't be above 99.4% since the boiling point would be below 32°F.

Edited January 9, 2012 by GlowingGhoul (log)

[Robert Jueneman]

GlowingGhoul, I've come to the same conclusion.

This morning, I went through the MVS chamber calibration procedure again. You put the machine into calibration mode, run it until the numbers stop incrementing, then do it again and hit reset wthen the number is one below the maximum reached on the previous run. But this is pretty obviously calibrating the vacuum setting against the maximum vacuum it is capable of producing, rather than an absolute setting.

So I went back to PedroG's chart at http://sousvide.wikia.com/wiki/Find_out_how_strong_a_vacuum_your_machine_produces, and tried to boil water.

First, I filled a coffee cup with crushed ice and distilled water, and measured the temperature as 0.01C. I saw tiny bubbles at that point, but certainly not a roiling boil.

Then it occurred to me that what I might be seeing was merely outgassing of the crushed ice, so I scooped out the ice and tried again. No boil.

To make a long story short, I had to go all the way up to 14.5C before I saw a reasonable amount of bubbles forming, so that was a true vacuum percentage of about 98.4%, as opposed to an indicated 99.9%.

Now, what could be the problem?

One possibility might be a leaking seal -- I see that the seal does not go all around the lid in on continuous piece, but is apparently cut and formed around it. I suppose I might be able to fill that tiny crack with some sort of soft glue.

Another possibility might be if I had water bubbles in the oil, perhaps from cooking Heston's triple-cooked French fries.

Or maybe there is a leak in the tubing or valve that lets the air back in at the end of the cycle.

I'm going ask blackp, who owns a Henkleman and who has also never seen meat boil, to check his absolute vacuum level with this procedure, as well as Douglas Baldwin, who has an MVS-31X.

In the meantime, I would ask anyone else on this list with a chamber vacuum to repeat these same tests. Maybe we can conclude something, finally.

[Robert Jueneman]

I was talking to Doug at Doug Care (where I bought my MVS-31X) and learned something new.

First of all, occasionally running the machine on 99.9%+30 seconds (a couple of times a day, for example) will help to get rid of any water bubbles that might have gotten into the oil, perhaps because you were cooking Heston Blumenthal's triple-cooked french fries.

Second, if for some recipes you need to hold a vacuum for an extended amount of time, you can run the 99.9%+30 second program, and when it gets close to the 30 second mark, simply turn off the machine. It will probably hold a decent vacuum (and you will be unable to open the lid) for 20 minutes or so.

[GlowingGhoul]

On my Henkelman, there is a "pump conditioning cycle". This runs the pump for 10 minutes.

The manual says that the purpose is to get the oil hot enough for any moisture in the pump to emulsify into the oil, preventing corrosion from degrading the pump. They recommned running that cycle once a week or after sealing lots of high moisture product.

I know other manufacturers have similar conditioning/cleaning programs.

The bottom line seems to be that you've got to get that oil good and hot in order to effectively remove moisture. When I touch the sight glass after the cleaning cycle it's not scorching hot, but uncomfortable enough that I woudn't want to leave my finger there.

The also recommned getting the oil hot before changing it, so as much of the old stuff as possible flows out.

Have you gotten any boiling in your Minipack yet?

[Robert Jueneman]

Yes, but only with distilled water at 14.5C.

And when I mention the issue to Doug Care, he said that he had never seen meat "boiling" either.

Maybe it depends on what side of the street you live? :

[pep.]

I'm still looking for an affordable chamber vacuum machine. I like to cook sous-vide a lot, but it's mostly a weekend thing. About once a month, I've got > 10 guests, but outside of dinner parties, it's a 1-person household with a second person on most weekends. Occasionally, I like to buy meat in bulk at a farmer's market and I've got a large freezer.

So while I will be using the vacuum machine frequently, heavy usage will be sporadic. I'd like to be able to the various recipes from MC, though.

Currently, I'm looking at the following machines:

• Besser Vacuum EOS (large chamber, no sensor or soft-air, ~1800 Euros)
  
• Henkelman Jumbo Plus (smallish, no sensor, automatic soft-air that can't be disabled, ~1800 Euros)
  
• Henkelman Boxer 35 (a bit large, with all features ~3000 Euros)
  
• Komet Vacuboy (lighter than Boxer, a bit cheaper without the external container option, ~2400 Euros)
  
• Vac-Star S-210 SX (smaller & lighter than Boxer, most sophisticated controls, ~3000 Euros)
  

Honestly, I think the Boxer 35 was a bit too large for my kitchen area (the physical machine that is). All the machine have Busch pumps, though with the exception of the Boxer 35 all have 8 or 10 m2 pumps. While I could afford the 3000 Euros, it seems like could get a lot of other useful stuff (like a high-powered blender) on the price difference. On the other hand, I'd hate to buy a machine for quite a bit of money only to find out that it's not the same without one of the more advanced features.

BTW, how useful is the external container (GreenVac) feature? Anybody using it? With my current edge sealer, I mostly use external sealing for vacuum marinating/compression. With a chamber machine, that could be done in a bag. But there might be other uses I'm not envisioning?