Freeze Dryers and Freeze Dried Food (Part 1)

[Deryn]

Re-reading my long post, I am embarrassed because I see I never got to the crux of the matter. Circular thinking and stream of consciousness writing. Bad habit.

 

So, to simplify - how are they the same? They are all methods of preservation.

 

How are they different? In a million ways, apart from just method. Taste. Texture. Longevity. Form. Uses for end product. Reversibility to original 'fresh' state.

 

Sometimes, as Kerry pointed out with her kimchi example, Huiray's mentioned processes can be used as simply a step to the final product (which includes FD'ing as the final stage). Could this be reversed (in other words, can one take plain freeze-dried ingredients and later reconstitute and salt or smoke, or even dehydrate them?) - I expect one could in many instances, though why one would dehydrate a reconstituted freeze-dried product I don't know right now ... but stay tuned. I bet some among us will play with stuff enough that we may find this answer too.

Edited October 19, 2014 by Deryn (log)

[dbinokc]

This is a question to Harvest Right. Is there a timeout somewhere so if a vacuum is not achieved withing a certain amount of time, then shut off the vacuum pump.

 

I ran into a situation today where I forgot to close the drain valve after a restart. An hour or so later I noticed this haze in the house. I checked the FD and sure enough it was blowing an oil mist all over. I had just refilled the oil and I am guessing it blew about a quarter of its oil out. If I had not been home, it could have blown out all the oil from the pump and damaged it. I would even say there is a potential for a fire in this type of situation.

 

If there is not a vacuum timeout feature, then I think one should be added. I would not think it would be too hard to add a check to the firmware to turn off the vacuum pump if some amount of vacuum is not pulled in a certain amount of time.

Edited October 19, 2014 by dbinokc (log)

[Mr. Mike]

IMHO.. FDing is a FAR superior method of preservation vs canning or dehydrating.  The various types of preservation all have their place and advantages and disadvantages, but as far as a preservation method-process...nothing holds a candle to FDing for longevity, “freshness” and nutrition retention.

 

Cons: Can’t do butter by itself, high fat products. i.e. sausages, rib eyes etc. Chocolate, honey or bread.

 

Dehydrating:  I have 4 commercial dehydrators... It's “da stuff.com" for making jerkies and fruit leathers.  And for the holidays I make about 150 lbs of jerky… 10 flavors.. 15# batches…everyone loves it… not the typical flavors….  All “signature” flavors.  Like Jalapeno maple, Jamaican Rum,  ..that one seems to be the favorite of all flavors of everyone that tries it.  I make a ground meat, round stick.. easier to do vs. a cut strip.

 

Cons: Everything else dehydrated is a slow cook and shrivel process of which I don’t like the end result, but it’s better than nothing.  i.e. veggies.  Spices ok..

If ANY moisture is left in the product. Spoilage-mold is just a matter of time.

 

Canning.  Foods are easy to use right out of the jar.

 

Cons: Too bulky, have to watch it while it cooks/pressurizes.  Have to mess with glass –handling how many times to process???, lids, rings, sterilization  .. no thanks…not for me.  Shelf life.. 5 years max?  with a “mushy” texture.  Need "commercial" shelving to hold all the weight.

 

This is why I bought my first FD’r.  Realized one would not be enough for the quantity I was wanting to do.   I cook 20-40 lbs of meat at a time.  One unit would take a LONG time to go thru 40 lbs. Bought a 2^nd machine to help and realized that wasn’t even enough capacity.

 

So I bought a 3^rd machine. I can process 25-30 lbs of product a day if I want.  (Yes.. that is part of a future business plan I have.)  I will say this…..3 machines are a handful to keep running while having another primary business I own/run.

 

 

Hope this helps.

 

Mr. Mike

[Mr. Mike]

The "Close the valve" issue.

 

EVERYONE will do that at least once....(me)..I've run my pumps dry TWICE! Don't feel bad... it is a PIA to clean up though. I will say that.

 

TIP:

To eliminate the "Misting Fog".. I placed a plastic solo cup over the vertical pipe

 

 

The misting oil does collect and run down the cup and ont the motor area.  I need to add another cup under that one to catch the oil that collects on the "misting cup" interior until I make another process improvement.

 

I will modify the vertical pipe attachment and add a few elbows and a short pipe to the unit and allow the mist to be contained in a cup that "hangs"  vs. covers the vertical portion and collects the oil to be reused. .. one of those "Round Tuit" projects.

 

This is prolly won't happen more than once..  IF you don't catch on to check the drain valve position everytime after the first time its left open.. It will happen every time.  OK... you can have lightening hit twice..( I have ) it prolly won't happen a third time-I hope anyway...(me).

 

"Murphy" and "operator error" live at our place some days.

 

I'll call Matt at H. Right Mon. and talk to him about the software improvement...I have a call into him for another matter from last week.

 

He's pretty good about returning my calls.

 

Mr. Mike.

Edited October 20, 2014 by Mr. Mike (log)

[dbinokc]

I do the same cup trick on mine as well. That works ok for some mild sptting, but not today.

[Kerry Beal]

I find the cup blows off when the vacuum pump starts up.

[huiray]

Do we mean the vent or the exhaust?  Mr Mike, I'm a little surprised to see that the vent (exhaust?) on the direct-drive pump you have (and picture) appears to be a single-unit thing attached straight to the body of the oil depository of the drive cabinet and then bent at 90º, assuming that is what you parked the plastic cup on.  (And is not the handle for helping to lift/carry the pump).  The exhausts on the direct-drive vacuum pumps I have come across in my experience (which is different from yours of course) were all ports with a coupled flange available (or convertible to one**) for attaching a mist trap...  Many mist traps also have a little flow-back tube for the condensed oil from the trap to the bottom of the vent port for delivery back to the oil chamber of the pump.  If the bleed/vent is meant, then I've never experienced oil blowing out of it - it just draws air into the pump chamber if not closed and the pump becomes very loud (and blows out much more oil through the exhaust :-) )  Hmm.

 

**Rotary (belt-driven) vane vacuum pumps tended not to have the flanged exhaust but one could unscrew the fitting and replace that with a flanged one with the requisite coupling for a mist trap.  Direct-drive pumps (in my experience) had the flanged coupling exhaust.

Edited October 20, 2014 by huiray (log)

[Deryn]

 

Cons: Too bulky, have to watch it while it cooks/pressurizes.  Have to mess with glass –handling how many times to process???, lids, rings, sterilization  .. no thanks…not for me.  Shelf life.. 5 years max?  with a “mushy” texture.  Need "commercial" shelving to hold all the weight.

 

Not to take this thread off into the weeds, and certainly not to disagree with you about canning in general, but retort canning does eliminate 'some' of your objections - no rings, glass jars, extra sterilization of bits and pieces, and weight/storage issues. It has its place too, but, as you say, and I concur, FD'ing is the new and better way to go for most things.

Edited October 20, 2014 by Deryn (log)

[Deryn]

Just ordered my FD'er. Will be several weeks before I get to use it but I am excited. Current (for October) unadvertised special is instead of bags, impulse sealer and absorbers, one can choose free shipping (in the US only though I think - forgot to ask since I am currently in the US), just fyi.

[Kerry Beal]

Just ordered my FD'er. Will be several weeks before I get to use it but I am excited. Current (for October) unadvertised special is instead of bags, impulse sealer and absorbers, one can choose free shipping (in the US only though I think - forgot to ask since I am currently in the US), just fyi.

Excellent - can't wait to have you playing along.  Free shipping was only to the US - but as I recall they offered me a discount equivalent to the free shipping in the US.

 

Do we mean the vent or the exhaust?  Mr Mike, I'm a little surprised to see that the vent (exhaust?) on the direct-drive pump you have (and picture) appears to be a single-unit thing attached straight to the body of the oil depository of the drive cabinet and then bent at 90º, assuming that is what you parked the plastic cup on.  (And is not the handle for helping to lift/carry the pump).  The exhausts on the direct-drive vacuum pumps I have come across in my experience (which is different from yours of course) were all ports with a coupled flange available (or convertible to one**) for attaching a mist trap...  Many mist traps also have a little flow-back tube for the condensed oil from the trap to the bottom of the vent port for delivery back to the oil chamber of the pump.  If the bleed/vent is meant, then I've never experienced oil blowing out of it - it just draws air into the pump chamber if not closed and the pump becomes very loud (and blows out much more oil through the exhaust :-) )  Hmm.

 

**Rotary (belt-driven) vane vacuum pumps tended not to have the flanged exhaust but one could unscrew the fitting and replace that with a flanged one with the requisite coupling for a mist trap.  Direct-drive pumps (in my experience) had the flanged coupling exhaust.

I like this idea - must look into a mist trap.  

Edited October 20, 2014 by Kerry Beal (log)

[Deryn]

I took the free shipping (supposedly $250 value to here) since I already have a mound of mylar bags in many sizes, and several ways to seal. I got extra stainless trays but forgot that I should have ordered some O2 absorbers (mine are old and I don't trust them right now) - will get those from Honeyville probably.

 

Wonder too if I should have ordered oil as well - I live in the boonies - is the oil a common item I can get at most automotive places? I do have some oil for my chamber vac on hand - perhaps that will get me through the first while if it is the same type (but I am not home in NS to check right now).  

 

Will be watching to see how this 'misting' issue is best addressed. I may post a big red sign on my FD'er to remind me to make sure valves are open and closed as directed as I hope to avoid this issue. Thank you for posting about this though - because I didn't know about it and the thought of cleaning up sprayed oil from ceilings, etc. is not my idea of fun.

 

Would it be easy, if we knew right specs, to attach such a mist trap (for someone not skilled at all in the plumbing area)?

[Kerry Beal]

Got my oil from Amazon.ca for a good price.  Link.

 

 

[huiray]

I took the free shipping (supposedly $250 value to here) since I already have a mound of mylar bags in many sizes, and several ways to seal. I got extra stainless trays but forgot that I should have ordered some O2 absorbers (mine are old and I don't trust them right now) - will get those from Honeyville probably.

 

Wonder too if I should have ordered oil as well - I live in the boonies - is the oil a common item I can get at most automotive places? I do have some oil for my chamber vac on hand - perhaps that will get me through the first while if it is the same type (but I am not home in NS to check right now).  

 

Will be watching to see how this 'misting' issue is best addressed. I may post a big red sign on my FD'er to remind me to make sure valves are open and closed as directed as I hope to avoid this issue. Thank you for posting about this though - because I didn't know about it and the thought of cleaning up sprayed oil from ceilings, etc. is not my idea of fun.

 

Would it be easy, if we knew right specs, to attach such a mist trap (for someone not skilled at all in the plumbing area)?

 

The manufacturers of the direct drive vacuum pumps I have dealt with do not recommend using automotive-grade oil, IIRC.  One uses a special high-grade oil which is pale to light yellow in color and designated for use in vacuum pumps.  I don't know what the freeze-dryer people will do but when I've ordered vacuum pumps before (and I've ordered quite a few) the pumps always shipped with a couple of jugs/bottles of oil sufficient to get you started (with a little left over).

 

One simply buys the mist traps.  They are not exactly 99¢ each, of course. :-)  It is simple to "clamp" it to the pump exhaust, provided the requisite flanged port is on the pump.  We are talking about a home environment, of course, so one can do whatever one wishes - but in a corporate/commercial scenario the safety inspectors often require (or strongly recommend) that mist traps be attached to vacuum pump exhausts.  There is almost always a very fine, invisible "mist" of oil that is ejected from the pump - *especially* when the vacuum is first being established (evacuation of your freeze-dryer in the current case) which accumulates in the atmosphere of the immediate area and gets deposited on surfaces over time (or gets breathed in by you).  Let alone visible blasting of oil particles from the exhaust into the air!

P.s. If you overfill the pump with oil (above the max level) you WILL have quite visible ejection of oil from the exhaust port and even from the fill-port (if not already recapped) when you turn the pump on. :-) ;-)

 

ETA: Actually, when we got lab-standard freeze-dryers (manifold type) I remember now we also got the oil shipped along with it.

Edited October 21, 2014 by huiray (log)

[Deryn]

Thanks, Kerry. Ordered some.

 

Thanks, Huiray. Guess I should not plug it in right under a silk evening gown in my closet then. Good to know.

[Mr. Mike]

PRE FREEZE CHECK LIST:

 

Well.. I "almost" did it again.... started a batch and left the drain valve open.

I caught it before the pump kicked in..1.5 hrs before a major spew happened.

 

SO.. Like ALL pilots.. (I'm not) they have a "Pre-Flight Check List"

 

Well 'Ol Mr. Mike... made his "Pre Flight Check LIst"...  the format got screwed up in the transfer... but you get the idea.

 

The drain valve position are in red for a reason...that is THE most important step.. IMHO.. 

 

This list will be laminated and a dry erase marker will be used to mark off the "cycle" the oil is on with the current run.

 

This list is for/after the product is inside the machine.

 

Feel free to "Steal" it if you want.

 

Any additions to the list.?

Thoughts?

 

I was in a hurry this morning.. put the food on the trays and zoomed out of the garage...

Came home in TOTAL dis belief about ME...  well not any more...

 

 

        Start Up Check List

1.  Is The Drain Valve Closed?

2.  Drain off Water in Vac. Pump Oil Reserve

3.  Oil Level Ok.. Add?

4.  Pillow in Position

5.  Door Fully Closed-Locked

6.  Start Cycle

7.  CHECK DRAIN VALVE POSITION  

 

CYCLES ON OIL

 

1      2      3      4      5      6      7     8    

 

Hope this helps..

 

Mr Mike

Edited October 24, 2014 by Mr. Mike (log)

[loosethreads]

Great idea Mr Mike! I almost did "it" again yesterday also. A checklist will be posted on my machine too !!

[dbinokc]

A few more items you might add to the list.

1. Make sure drain valve is open when the unit is finally turned off. Somehow I actually managed to do this one. Ended with water all over the floor!

2. Make sure drain bucket is empty of water. I read elsewhere where someone had manged to fill up the drain bucket enough to submerge the drain tube. When they

opened up drain valve to release the vacuum, water was sucked up into the chamber and making a big mess and soaking the food. I have not done this one yet, but give

me time.

3.Make sure drain tube is in the bucket! Done this one, but caught it before I had as big a mess as in 1.

[Deryn]

Thanks, Mike and dbinokc. Notes/list duly 'stolen' from both of you.

[Harvest Right]

Chocolot-

 

The cream cheese came out and it looks awesome!. You are welcome to stop by any time to pick it up. Always excited to see (and taste) the treats you make. 

[Chocolot]

Chocolot-

 

The cream cheese came out and it looks awesome!. You are welcome to stop by any time to pick it up. Always excited to see (and taste) the treats you make. 

Thank so much. I'll probably be in sometime next week. 

[Mr. Mike]

Here are the latest items dried:

Cream cheese.. Blueberry, strawberry, Honey Almond

 

Pasta-Potato: Truffle Mac n Cheese,  Cheesy S.W. Potatoes.

 

Sweet Potatoes-canned.

 

Hummus: Red pepper and Garlic herb.

 

 

Pumpkin Pie

Pumpkin Pie: Like candy when eaten dried.  Re-constituted the pumpkin gets mushy, the crust is really crunchy.  Good contrast.. creamy sweet with a crunchy sweet finish of the crust. Had to cut it up to have it "thinner" to dry and not be too tall in the dryer.

 

 

Lessons Learned-Results:

Cream Cheese: Bought the flavored kind in the store. Dried it has a chalky consistency until you start salivating… then it turns creamy.. It makes a GREAT snack…had a hard time not wanting to eat it all.  Drying on wax paper would make removal easier.

 

Pulverizing it in a plastic bag helps with re-constitution…less lumpy.  Add water to your desired consistency… Did two types.. a little more runny and one very thick… both were pleasing to the pallet.  Blueberry and Strawberry.. KILLER good.

 

 

Pasta n Potato… Ok eating dried… didn’t re-constitute.

 

 

Hummus: It will stay together when lifted out of the pan.  Turns to powder pretty easy when touched –handled roughly. 

 

 

Sweet Potatoes: These were canned.  One can is all you can do in the machine… even drained has a lot of ice after drying 24 hrs.  Quick turn time. Really crunchy and very sweet.. (duh)   Need water to eat more than a biteful.

 

 

I’ll be buying cream cheese in bulk blocks, pureeing different fruits.. Strawberry, blueberry, peach and maybe doing a jalapeno jelly c. cheese.  I might cold smoke the peach cream cheese for a different kinda flavor.

 

I scored the c. cheese and hummus for easier removal.

 

Saved in mylar what I didn’t eat.

 

Hope this helps or spurs innovation.

 

Questions?

 

Mr. Mike

 

The last two pictures... don't know how they got there... I don't see them in the post previous jpg preview.

sorry.

Edited October 28, 2014 by Mr. Mike (log)

[Deryn]

Thanks so much, Mike, especially for the pictures and your taste test reviews.

 

Question about the pumpkin pie - you said dried it was like candy but that you reconstituted it and the pumpkin went mushy but the crust was still crunchy? Edible still in that form too?

 

I would say that one would need liquid to drink alongside if one ate much of any freeze-dried foods in their dried form since they will rehydrate in your gut anyway - and dehydrate you unless you replace the liquid there quickly.

Edited October 28, 2014 by Deryn (log)

[Mr. Mike]

The pumpking pie was pretty..no... REALLY good.. just used cold water.. about 1 TBL for a small chunk and let it set for about 3-5 min. max...the pie part just 'slurried apart" in the spoon and palet.  The crust was a really nice treat... crunchy and sweet.  I'll be doing more of those for sure.

 

In the dried state, it is "obviously"  hard but would make a good "just e-nuff" sweet-snack for after dinner...or the late night "sumthin' sumthin' "

 

Mr. Mike

Edited October 28, 2014 by Mr. Mike (log)

[Deryn]

Thanks, Mike.

 

Perhaps Chocolat or Kerry will make freeze-dried pumpkin pie truffles! I think maybe a white chocolate covering might be more appetizing somehow since I don't associate those flavours with dark chocolate - but let's see what the chocolate experts think.

Edited October 28, 2014 by Deryn (log)

[Kerry Beal]

Thanks, Mike.

 

Perhaps Chocolat or Kerry will make freeze-dried pumpkin pie truffles! I think maybe a white chocolate covering might be more appetizing somehow since I don't associate those flavours with dark chocolate - but let's see what the chocolate experts think.

Not I - not a fan of pumpkin truffles!