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Mr. Mike

Tried and True Freeze-drying Outcomes

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CALLING ALL FREEZE DRYER OWNERS:

Project: Freeze Drying: A Quick reference guide for Tips, Hints and FAQ’s for Freeze Drying. i.e. Collector document.

As part of trying to organize all the different questions and topic discussed, I made a proposal to organize the different topics for new and seasoned owners for their results and experiences in using our freeze dryers.

We have support from the higher ups for organization, editing and posting this Freeze Drying Reference Guide.

Food drying is ONE of many topics that will be addressed in this reference guide.

Next: an outline for the Food drying results section.


Mr. Mike
 


Edited by Mjx Split original OP into two posts, to enhance accessibility. (log)

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[This was originally part of the preceding post; that has been split, to create a clear introductory post and a distinct, descriptive guideline post.]

 

 

Here is the outline for the Food drying results section.

 

The Big Picture:
Scope:
Collect our experiences for future reference who are new or want to know more on the freeze drying process and equipment.
Make a Reference document that will help summarize the topics and discussions for Freeze drying.

Objective:
To help prevent repeat questions for previously posted discussions.
To reduce the learning curve of new owners or anyone trying a new food item or technique.
To share experiences that other may not have considered and share specific problems with resolving issues for a specific problem or experience.

Goal:
To keep freeze dryer owners from having failures that can be avoided.
To shorten “The learning curve” of the freeze drying process.
To make a better product

YOUR HELP IS NEEDED:
Posting your efforts-results will be used for the foods that have been tried-dried and the good or bad results.

Input needed:
What is needed is your list of foods dried, the equipment used, and the results of the end product and if possible, reconstitution ratios (if you have done this) for what did- did not work. Most have tried similar veggies, dairy products, meats etc. It's OK to have multiple posts for a single food item as some will have different experiences.

I/we want to take those experiences and collect them for the reference of the group. Some of you have posted your results of all your efforts to date and that is an excellent start. Please re-post here. All of your results are needed.

Questions for this guide:
What food item was dried,
Make and model of freeze dryer,
Size of product- sliced, diced, whole size (measurement in inches, oz or lbs.)
Liquid-puree-paste etc and how much oz. did you dry.
Process Results: Product,-amount dried, approx. time to dry and results. What would you do different. Success-nothing to total fail for drying, results from drying are what were are needing.
There will be a "recommendations section" on each item for the problems that we have faced and what/how it can be improved/reduced/eliminated

For instance:
Maraschino cherries. Whole cherries w- w/o stems, 2-3 cups each, Time dried was 30 hours, Multiple foods dried with the cherries. Results- gummy-sticky. High sugar content is suspect for not drying. Not a good candidate for long term storage. Will not do again.

Pepperoni: Sliced, 5 lbs, 24- hour cycle, Results: “Crispy” but a very greasy mess. Cannot store long term. Will not do again.

Strawberries. Whole, 10lbs- 40 hours dry time. Results: Too much product in the dryer. Overwhelmed system with ice build up.
Recommended 5 lbs drying- sliced in half or thin sliced worked to completely dry product. Longer drying cycle needed.

Again- This is just ONE aspect of this Reference guide see link here as posted in the Moderation and Policy section for the Other topics proposed for the Freeze drying guide.

Your input for the other related issues. please post there. We want to keep the topics from being "blurred" in these posts.
This is for US and you have input on how this could be improved

Note: I have pulled together previous posts to help with the structure for the other sections of the guide.

Thanks for your interest.

Mr. Mike


Michaela, aka "Mjx"
Manager, eG Forums
mscioscia@egstaff.org

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This thread is to post the drying results here so it doesn't bog down the original thread. 

 

The information will then be taken and made as part of a larger reference document for anyone getting into freeze drying to help answer questions and hopefully reduce redundant posts on the main FD thread..

 

This effort is to hopefully make the start up and use of the dryers easier while reduce the problems that new owners experience.

 

Hope this helps.

 

Mike

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So I was successfully able to freeze dry whole strawberries.  I put 3 packages of frozen berries spread over two trays - 9 hours of freezing and 12 hours drying stage.  

 

The other items in the dryer at the same time were fairly low water.  

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for those wondering about the before and after weight, here is an example for those who hike and every once matters.

I bought a case of eggs and weighed the before and after weight by the dozen.

The average weight was 1.9 pounds/doz (without shells) and after was .55

I gave a couple FD dozen to the boy scouts for their next weekend campout along with some fruit. I figure they'll get a kick out of it.

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OK, I have now had my Dryer for about a month, I am in Australia, so I had to buy a bigger step down transformer than the one I already owned.

 

Batch 1:  Raw Minced meat ( Hamburger) I had pre frozen this in anticipation, I had spread it flat on a cookie sheet and then cut it up like large chocolate squares.

Was taking too long in my estimation ( about 30 hours) so stopped the machine, it looked dry enough so I packaged it.

Reconstitution was pretty instant, but a little harder to break up when cooking, a bit more like cooking from frozen.

 

Batch 2:  Red and Green Apples cut into small wedges skin on, took about 24hrs, only fit about 6 large apples, turned out nice to eat also stewed up nicely.

 

Batch 3:  Bacon almost all fat removed, 1 kilo fresh, only single layer, our bacon is a bit different than US more ham like, dried well in 18hrs, reconstituted and fried very well.

 

Batch 4:  Granny Smith Apples, cut with a slicer corer peeler. 11 Large Apples, after about 24 hours it finished but there were a few cold pieces which started to soften so put back in for 1 hr freezing (probably unnecessary) and 2 hrs drying, all looks good.

 

Batch 5  Pre cooked Mince (Hamburger) Liquid (fat and Gelatine) removed good stock, about 4 and a half kilo, did not note the time but about 24 hrs. Nice and crumbly.

 

Batch 6:  Teriyaki Chicken thighs cooked , and Diced chicken thigh cooked, added the fat and gelatine back to the mix, would not do so next time as there is fat attached to the cooked product, which may go rancid so will probably need to eat it up. Teriyaki  Chicken looks great, reconstituted great.

First mistake made forgot to close the water outlet...  Oil spurted out all over the top of the shelf the pump is on, stopped it lightly defrosted and started up again half hour freezing  several hours past and still no cycling turned off and decided to clean pump.  Full oil change, removed cover and cleaned out fully, small amount of rust.

Started again 1 hour freeze still cycling 8 hours later so stopped and removed food all looked dry enough.

 

Batch 7:  Blueberries Frozen, after 10hrs still not cycling and some oil escaping, so stopped reseated the rubber and set to drying, Blueberries nice and dry, small amount of mango on tray was not, so I ate this.

 

Oil looked rather milky so drained it again.

 

Batch 8:  Frozen Peas, reduced the freezing time to 3 1/2 hrs probably a mistake, the cycling kept going back to xxx stopped reseated rubber etc, could not pull a vacuum, in despair I stopped it put the food back in the freezer and went to bed, Rang HR told me to try starting the whole process again, still no luck with a vacuum and going back to xxx, rang a local vacuum pump company they tried to be helpful, I thought it might be the oil I had purchased locally, but all experts seemed to say it was ok.  Took a day or two to talk to these people so what to do now.  Oil looked ok so started the pump with no food set to drying pulled a total vacuum to 0mt so lets try next batch.

 

Batch 9:  Bacon...just to be safe 1kg about 20hrs all good.

 

Batch 10:  Grated Cheese, at 7am it showed it had 1 1/2 hrs to go but at 8.30am  was back to 6.50 hrs to go, left it alone and all finished at 3.45pm nice and dry.

 

Batches 10 and 1:  Mixed Berries frozen, strawberries cut smaller to make them more un form to Blueberries and raspberries, a bit overcrowded so after 26 to 32 hrs stopped m,machine defrosted and reset to drying , stopped and checked towards to end and Blueberries were still moist so reset both took over 42 hours each.

Oil Changed between these two batches.

 

Batch 12:  in now White Fish Fillets will post results later.

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Welcome to eGullet, Herdy! And thank you so much for your very interesting post about your first runs with your HR FD.

I see you had some ups and downs. There is definitely a learning curve and these machines have a 'personality' I swear, but, I hope you have generally had fun with it.


Edited by Deryn (log)

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I've been FD'ing fresh spinach leaves for my wife.  Turns out she really likes having them on hand!  Whole leaves, or better yet shredded with the veggie-slicing blade in the Cuisinart  (they pack in the tray better, but still are a bed about an inch thick).  Standard HR cycle works fine for this.  I think even a puree would work fine, depending on how large you want the chunks.  They are delicate and don't stay whole, so slicing them is a good compromise.

 

One thing I tried was putting the dried leaves into an electric spice/coffee grinder and making them into a verdant green powder.  This has been getting added to things like burgers (mixed right in the meat) to add a bit of a nutritional boost.  Haven't figured out an exact ratio of a tablespoon of powder to a number of baby spinach leaves, but the powder is pretty concentrated. It hides in the food well too, so makes a good fortifier. Stores in a small package, like a 4oz canning jar.  Peas and carrots seem to work this way too, and you can make some interesting patterns with them.  I'll be experimenting further along these lines.

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Freeze Dried Greek Yogurt

 

Harvest Right Freeze Dryer (touchscreen)

 

Quantity - 1 Quart (.946 liter) semi-liquid

 

Ingredients:
 - 1 Tablespoon yogurt culture taken from unflavored or vanilla commercial yogurt (Chobani in my case) -Amount can be anything from a teaspoon to a tablespoon - not critical

- 1 quart Half & Half  (regular half&half, not the "light" stuff - and NO, this is not a fat-free food! 9_9)

- Clean containers and a small whisk or fork

- Parchment paper for your trays

 

Process:
I use a home made sous-vide setup for my yogurt making, but use what you have as long as it can maintain a temp of 108F (42.2C) without overshooting more than a degree or two.  If you have a commercial yogurt maker, check the temperature to be sure it's between 105 and 108F.

 

Pour the half and half into a bowl and mix in the culture with a fork or whisk. Let this work for 12-15 hours in your yogurt maker/sous-vide gadget

 

When the time is up, you will have a very solid chunk of yogurt. It should be the consistency of heavy sour cream when stirred. If you want flavored yogurt, now is the time to add fruit or flavors.  I made some with pureed strawberry that came out very well.  Plain, unsweetened seems more versatile, so that's what I usually make. (you may just want to eat your first batch to see if you like this full-fat style of yogurt, trying different flavors - it's very rich and wonderful!)

 

Put parchment into your tray to prevent sticking,  and spread the yogurt to about 1/2 inch thick, or freeze in a silicone bar mold like this http://www.amazon.com/gp/product/B003VPZ14Q and place the frozen bars on the tray. (This bar method works well for a lot of liquid/slurry items, especially for portions of sauce)

 

Run the standard 9 hour freeze, 7 hour dry cycle.  

 

The product comes out as a brittle material that breaks down into fluffy powder, and should be carefully stored under vacuum or O2 free environment and well protected from light.  It is unknown how long this will store due to the fat content (experiments ongoing), but it should do well properly stored.  Reconstitute for use, or add to recipes. You can reconstitute with puree or juice for flavor.

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