Category Archives: Freeze Dry

Freeze drying leftovers

Freeze drying leftovers

Another terrific use for our Harvest Right machine is for freeze drying leftovers. As a family with children we generate our fair share of left overs. We try to use up leftovers but we often resorted to throwing food away before we bought our freeze dryer. Now that we have our Harvest Right machine no food gets thrown away because we are freeze drying leftovers.

Freeze drying leftovers
Freeze drying leftovers

A reason to buy a home freeze dryer

Recently I saw an advertisement from Harvest Right that claims the average person throws away something like 290 pounds of food annually. I decided to go looking for other sources to see for myself. This article suggests that the average family of 4 wastes around $2,275 worth of food yearly by throwing it in the trash. According to the EPA, “In the U.S., 40% of food is lost or wasted, annually costing an estimated $218 billion or 1.3% of GDP.”  That is a lot of wasted food and money

If our household falls close to that national average we could arguable make our machine pay for itself in two years.   If you add some loads of food from your garden it wouldn’t take long to make a home freeze dryer pay for itself.

What food could you avoid throwing away

In addition to food from your table you can freeze dry stuff like condiments, sour cream, pudding, milk, yogurt and fruit.  Bananas are one of the items that many homes invariably end up throwing into the trash.  Bananas freeze dry nicely and taste wonderful freeze dried.  They’re also very easy to prepare for freeze drying, we no longer throw away bananas.

Seasonal meals such as Thanksgiving and Christmas dinners often result in an abundance of leftovers.  Most of that leftover food will freeze dry nicely.  It can even be packaged into individual and complete meals to go into your food storage pantry.

Freeze drying leftovers
Leftover stew going into our home freeze dryer

The stew you see in the picture above is going to be stored in 7 mil mylar bags with a 300 cc  oxygen absorber once freeze dried.  It will be added to our food storage pantry once completed.

Freeze dried pudding

Freeze dried pudding

One of the new additions to our freeze dryer rotation is freeze dried pudding.  So far we have tried chocolate and vanilla flavors with good success.  Chocolate does not freeze dryer well but food that contains chocolate is often OK.  If the chocolate flavor will freeze dry I am confident other flavors will also freeze dry without any issues.

Pre-freeze the pudding in a mold

When we make freeze dried pudding we will place it into a silicone mold and pre-freeze it into 1 inch cubes.  Once frozen solid we push the pudding cubes out of the silicone mold into a gallon sized freezer bag.  We repeat the process until either we have enough to fill a tray, or until the mixing bowl is empty.

soon to be Freeze dried pudding
vanilla pudding frozen in molds before going into the freeze dryer

Those one inch cubes are a little bit bigger than bite size for the kids and is messy when they bite into the freeze dried pudding.  We are ordering smaller molds from Amazon.  Hopefully they will be of a size that the children can pop into their mouth whole.

Selecting the freeze dry cycle

As with all dairy products I like to do a custom freeze dry cycle.  Twelve hours freeze and another 12 hours dry time in our Harvest Right freeze dryer.  My first time do yogurt in these molds we still had cold spots and required a lot of extra dry time.  The cold spots indicate there is still moisture in the food.

It is entirely possible that the long dry time is needed because of the 1 inch cubes we are trying to freeze dry.  If we went with a smaller mold we could likely reduce the freeze and dry time.  When the new molds arrive we will try a load at the standard settings and see how they turn out.

Removing water from vacuum pump oil before filtering

Removing water from vacuum pump oil before filtering

Removing water from vacuum pump oil before filtering is important to help extend the life of the oil and your vacuum pump.  Water in the vacuum pump oil can cause corrosion and damage to the vacuum pump.  The toilet paper filter we made and use here will remove food particles from the oil, but it does not separate out the water.  In this picture you can see the water that has separated from the oil and sitting at the bottom of the jar.  It needs to be removed before filtering the oil.

Removing water from vacuum pump oil before filtering
Removing water from vacuum pump oil before filtering

How to remove water from oil with a water separator

You can use a fuel filter water separator to remove the water from your vacuum pump oil and filter it at the same time.   They run about $40 and will require fittings and pipes to allow the oil to be poured into the filter and allow the filtered oil to drain from the filter.  The whole system will also need to be mounted with all the attached pipes before you can use it.

There is a system out there called the Harvey filter that is made specially for Harvest Right owners.  His filtering system will cost you about $50 plus shipping.  You can find it and see videos on it at his website Harvey filter.

Freeze the water to remove it from the oil

Alternatively to building or buying a water separating oil filtering system you can simple freeze the water by placing it in the freezer.  Once frozen to the bottom of the container, one simply has to pour the oil off the ice into the toilet paper filter.

All of the oil wont drain out before the ice begins to melt.  We get the majority of the oil out and then place the jar upside down in the filter that came from Harvest Right with the freeze dryer.  It will go into the freezer eventually like the mason jars to remove the water.

Harvest Right filter

Homemade vacuum pump oil filter

Homemade vacuum pump oil filter

It is once again time to change the filter material in our homemade vacuum pump oil filter for our Harvest Right home freeze dryer. The oil filtering system is a simple one comprised of a Brita water filter. Their filter is removed from the pitcher and a new one is made by rolling up a large potion of a roll of toilet paper. That plug of toilet paper is made to be a little large in diameter than the hole where the Brita filter is intended to go.

Remove the old filter material

The old toilet paper filter will need to be removed and the pitcher cleaned. The old filter is going to be full of oil and food particles from the food that has been run through the freeze dryer. Gloves such as nitrile or Food handlers glove for handling the the old filter and cleaning up the pitcher are a good idea. You can grab the filter from the top and pull it out of the pitcher, or remove the part that holds the filter so you can push it out from the bottom.

A finger will work for most people to push the filter out from the bottom. For those with large diameter fingers an improvised tool such a pencil or screw driver will push the old used toilet paper filter from the pitcher housing. Having a rag or paper towel on hand to wipe the oil from your tool would be a good idea.

Clean out the Brita pitcher

After the old toilet paper filter is removed there will be a lot of gunk that is comprised of food particles that needs to be cleaned. We use paper towels for this task.  Here is what the inside of our homemade filter looks like before cleaning.

Homemade vacuum pump oil filter
This toilet paper filter needs replaced and the container cleaned

To prevent the mess from getting into the pitcher one should consider cleaning the mess out as much as possible before removing the filter material.  After we have wiped out the mess it is simple to push the toilet paper filter out from the bottom.  Here is what our filter looks like at the time we replaced it.  It is gross, but you can see all the food particles that this removes from the oil.

Homemade vacuum pump oil filter
Homemade vacuum pump oil filter after replacing filter material

Replace the filter material

Once the pitcher clean and the old toilet paper filter material is removed it is time to add the new filter. To replace the dirty filter material you see above just take a roll of your toilet paper and start rolling it.

You will want to make the diameter of the filter slightly larger than the hole in the pitcher.  When the toilet paper filter is pushed into the pitcher it should fit snugly but not require a lot of force to get into place.  If the filter fits loosely the oil will flow past it and not get filtered.  If it is too tight the oil may not pass through the  roll.

Here is our homemade vacuum pump oil filter cleaned, a new toilet paper filter is in place.

New toilet paper filter installed
Homemade vacuum pump oil filter

Which Brita pitcher to use

I prefer the larger pitcher that can handle a couple quarts of oil at a time.  We bought the 10 cup Brita filter and are very happy with it.  These are often available used at 2nd hand stores for a few dollars.  You can expect to spend 20 to 30 dollars if you buy one new

Freeze dry apples

Freeze dry apples

Today we are setting up to freeze dry apples again.  The freeze dryer is still new to us and this and apples are very easy to freeze dry.  An added bonus for us will be that the kids absolutely love them.

Freeze dry apples
freeze dried apples vacuum sealed with oxygen absorber

When freeze drying anything it is important to have the items being freeze dried to be consistent in size.  This ensures everything in the freeze dryer has the moisture fully removed.  This of the utmost importance to ensure it will survive in long term storage.  If there is moisture left inside one large or extra thick piece of food it can cause spoilage.  One piece starting to spoil can ruin everything in the same container with it.

An apple slicer that is designed to be pushed down to core and slice works, but we found the slices were too thick.  The thick slices makes proper freeze drying more difficult and increases the run time on the dryer.  Our first load of apples with the push style slicer and corer took over 40 hours to complete the freeze dry cycle.

Apple slicer, corer and peeler

To get consistent apple thicknesses we bought this little hand operated apple slicer, corer peeler.  It peels, slices and removes the core all at the same time for less than $20.  It includes a section cup base that holds it in place on tables and counter tops.

freeze dry apples

We use ours mounted to the counter on one corner of the sink.  With a mixing bowl placed in the corner of the sink under the device its a simple task to get those apple peels into the bowl.

Because the device cuts the apple as it rotates and moves closer to the cutting blade the sliced apple will be in one long curlicue slice.  Cutting through one side will give you rings.  The rings are too big to go into mason jars easily.  We cut down the middle into symmetrical half moon shapes.  These are bite sized and easily go into and out of short term jars.

Why filter vacuum pump oil 

Why filter vacuum pump oil

In another blog post I discuss the process of filtering vacuum pump oil. But why filter vacuum pump oil?  Cleaning and removing water from your oil allows you to reuse the expensive vacuum pump oil several times.  Refilling the vacuum pump with clean oil that is free of water helps ensure the pump has a long life.  Continually operating the vacuum pump with dirty oil that contains moisture will lead to early pump failure.

In the picture below you will see vacuum pump oil in a quart jar.  This oil ran one complete freeze dry cycle before being drained into the jar,  It sat for around 24 hours to allow the water to collect at the bottom.  The cloudy mess in that jar is food particles from the food.  It is drawn out of the freeze dryer as the vacuum pump pulls a vacuum on the chamber and makes it into the oil.  You will be able to see what the oil should look like below after I discuss removing the water from the oil.

Why filter vacuum pump oil 
Why filter vacuum pump oil

Remove the water from the oil

To remove the water from the used vacuum pump oil we start by draining the used oil into a quart mason jar.  Secure a lid and ring on the jar and place it into the freezer and allow the water to freeze solid.

You can see the water under the oil in our mason jar in this picture.  This was a significant amount of water and is not typical.  This was a result of a long freeze dry cycle with a full load of very high moisture content food.

Why filter vacuum pump oil 
remove water from used vacuum pump oil

Once the water is frozen solid pour off the oil into your filter and allow the very viscous oil to drain into the toilet paper filter.  (You can see my Brita TP filter in the picture at the bottom of this page.)

After the majority of the oil is out of the mason jar and before the water begins to melt, I transfer the jar to the filter that came with the Freeze Dryer unit.  There the remainder of the oil drains from the jar along with the water as it melts.  Once there is a fair amount of oil in the Harvest Right filter it too will go into the freezer to remove the water.

Here is what it looks like after filtering

This is the exact same oil as shown in the first picture after it went through our toilet paper filtering system.  The difference is remarkable. One can see how much particulate matter was in that oil before filtering.  Clean and filtered vacuum pump oil generally should look like this amber color.  Some vacuum pump oil will be a different color, but this is what our Black Gold oil looks like.

Why filter vacuum pump oil 
Clean vacuum pump oil after filtering

So why filter vacuum pump oil?  doing so will reduce operating cost and help reduce expensive repairs to the vacuum pump.

Filtering vacuum pump oil

Filtering vacuum pump oil

Filtering vacuum pump oil is a part of owning a home freeze dryer.   It is necessary to remove moisture and food particles from the oil through filtering.  Oil from the vacuum pump should be filtered after every load. This helps to ensure a long life of the vacuum pump.

When you purchase a Harvest Right freeze dryer you will receive a filter like the one in the picture below.  The Harvest Right filter is the one on the left.  It works and does filter out the particulate matter.  Unfortunately I found it to be poorly assembled and messy to use.  The Brita filter on the right is what we now use.


The Harvest Right oil filter

If you look at the picture above you will see the Harvest Right filter on the left.  Initially we used the HR filter that came with the freeze dryer.  To remove the filtered oil you have to unscrew the lower lid and lift everything out of the bottom container.  It will drip oil and needs to be placed on something to soak up any oil.  We grew tired of the mess and having to assemble and disassemble the filter.  Now we use the Brita filter on the right in the picture.  It is discussed below.

Our Brita oil filtering system

While this system is what we currently use, the idea wasn’t our own.  We borrowed the idea from a freeze dryer group and have  adopted it for our purposes.

For our filtering system we bought a 10 cup Brita pitcher.  These filtering pitchers can be bought new for around $25.  For the bargain minded folks, try looking for one in thrift stores.  I’ve seen people reporting to find them for just a few dollars.

This Brita filter uses toilet paper rolled up to remove food particles.  The toilet paper rolled up will replace the charcoal filter.  As the filter gets full simply replace the toilet paper.  In the picture below you can see an example of the filter material needing replaced.

How the Brita filter is better than the Harvest Right filter

The Brita filter does not require disassembly to pour the filtered oil back into the vacuum pump.  So long as there isn’t oil in the upper chamber you simply grab the pitcher and pour the clean oil.

A quick important note, the toilet paper filter does absorb some oil and you will lose some of it.  You will need to have extra vacuum oil on hand to replace what is lost each time you add new filter material. Black gold vacuum pump oil is what we use and is one of the two brands recommended by Harvest Right.

See how to change your own filter material in a home made vacuum pump oil filter.

Home freeze dryer

Home freeze dryer

Recently we bought a home freeze dryer from Harvest Right.  We have done several loads and are doing well with it.  There is still a lot to learn and you can expect to see more related blog entries on our home freeze dryer in the future.  Future topics will be filtering and reusing vacuum pump oil, food successes and failures, long and short term food storage.

Home freeze dryer
Home freeze dryer

why buy a home freeze dryer?

The decision to buy a home freeze dryer is one that shouldn’t be made lightly.    These units are expensive and require your time to prepare food for freeze drying and putting it away properly.  After every freeze drying cycle with your home freeze dryer the oil needs to be drained and filtered.  The process isn’t hard but will require your time.

For us being able to store the food from our garden long term with little nutritional value loss was very appealing.  We know what goes into our garden, the seeds that are used.  We control the insects so we know exactly what has been used.  Buying commercially grown food you have no idea what is used or how it was prepared for market.  Putting away our own food that we control during the entire growing process up through harvest gives us a piece of mind.

Extending the amount of food in our pantry is another reason we elected to buy the home freeze dryer.  Sure, we could be a bunch of commercially prepared freeze dried food with what the unit cost.  By doing it our selves we have better control over what food ultimately goes into our pantry.  Plus over the course of a few years we should be able to make this unit more than pay for itself.

Little nutritional value loss with a home freeze dryer

We can and freeze but both of those options are more of a short term option.  Add to the shorter storage duration is the nutritional value loss that comes with heating food.  Whether you blanch before freezing, dehydrate or can you can expect up to around a 30 percent loss of nutritional value in your food.  Harvest Right claims a mere 2 percent loss through freeze drying.

Of course foods that were prepared before freeze drying, or that will be prepared after re-hydration will still experience loss of nutritional value.  But anything that can be eaten as a snack right of the freeze dryer will retain all that nutrition.

Things to consider before buying a home freeze dryer

Before buying a freeze dryer we would recommend you consider several things before buying,  First off, do you have time to prepare the food to go into the freeze dryer and then to store it once it has completed.  peeling, slicing and arranging food in the trays can be time consuming.

Properly storing food for long term storage takes attention to detail.  If you’re rushed for time and hurrying to get the task done and do something improperly you can lose everything in that pouch.  If your schedule is hectic and you’ll have difficulty finding the time to load and unload the freeze dryer it will likely sit unused.  A freeze dryer sitting unused would make it a very expensive paper weight.

The cost of electricity is something else you should consider.  Here in the midwest our electricity costs are lower than can be found on the coasts.  We also don’t have a fluctuating rate depending on peak hours.   A typical load will have this unit running constantly for 24-30 hours.  If you pay peak electrical rates a home freeze dryer will be running at those times and could significantly increase your power bill.  The large unit runs on 220 volts and would be more economical.

The vacuum pump can be loud.  Setting it up in an area close to bedrooms could interrupt with sleep.

The vacuum pump needs to be kept cool and the freeze dryer will be more efficient if kept in a cool room.  A garage or shed that gets hot during the summer months can causes extra wear and tear on your pump and freeze dryer.

Harvest Right recommends your freeze dryer be on its own dedicated circuit.  If you place it on a circuit with other appliances you run the risk if tripping a breaker.

What size freeze dryer do you need?

Currently Harvest Right offers three sizes of home freeze dryers.  Picking the one that is right for you and your family can be difficult task.  The number of people that will be using the food coming out of that freeze dryer needs to be considered.  It might even be good to call Harvest Right and ask them which model they’d suggest you needed.

Based on our experiences I’d say 1-2 people would need the small unit.  For 3-4 the stand model.  But for anyone freeze drying for 4 or more people you should absolutely consider the large model.

We are members of a few different freeze dryer groups on Facebook.  Often times when someone asks for suggestions on which size they need I’ve seen people say they wish they had bought a larger unit.  I’ve yet to see a single person say they wish they had bought the smaller unit.

What else do you need for your home freeze dryer?

Unfortunately there will be more things you’re going to need to go with your home freeze dryer.  Many of those other items you can get from Harvest Right.  They even offer an occasional sale that will include many of them.  The sale, when running will include oxygen absorbers, 7 mil mylar bags, and the impulse sealer you will need to seal them.

Silicone tray liners make cleanup and removing freeze dried food from the trays so much easier.  Harvest Right offers them to correctly fit their trays.  They have three different sizes to fit the trays for the freeze dryer you buy.

Consider an extra set of trays.  An extra set allows you to prepare the next batch of food and have it ready to go into the freeze dryer.  A second set of the liners would be wonderful.

The vacuum pump comes with one quart of the correct oil.  The oil needs to be filtered after each use.  The filtering process will not return all the oil as some stays in the filter.  To remove the water and properly filter the oil can take several hours.  Having extra oil on hand allows you to quickly get the freeze dryer back in operation.  Having at least an extra gallon of the correct Black Gold vacuum pump oil is suggested.  Some retailers will ship for free if you have Amazon Prime.

Our favorite freeze dried food

So far Gala apples and bananas are among our favorite foods to eat directly out of the freeze dryer.  Bananas are possibly our favorite because they’re relatively inexpensive as compared to other fruits and berries.  Blackberries and strawberries are my own personal favorite.  The kids enjoy ice cream, yogurt and water melon.