Fowlers Vacola bottling is a ‘slow water bath’ method, where you fill clean Fowlers Vacola bottles with high acid contents (such as tomato sauce, pickled onions, apricot halves). The bottle has a rubber ring, a specific preserving lid, and a spring clip, which holds the lid in place during processing. The filled bottles with their lid and clips applied, are submerged under water in a Fowlers Vacola preserving unit. The Simple Natural Preserver unit is turned on and heated, for 60 minutes (70 minutes for no. 36 bottles).
The ‘high acid’ contents means an environment in which many microorganisms which spoil food or make it unsafe, are unable to survive. The temperature obtained (92’C) pasteurises and destroys any food spoiling enzymes, and food spoiling/ foodborne illness microbes which may be present. The processing also forces oxygen from the bottles, creating a vacuum (anaerobic) environment, which inhibits survival or growth. Then as the bottles cool after being removed from the water, a vacuum seal is created, which prevents recontamination and air entry.
- many fruits (to use in desserts, sauces and baking)
- jams, conserves and fruit preserves
- relish, chutneys
- passata or whole tomatoes
- pickled vegetables
- It can be an affordable way to get started, as you can find Fowlers Vacola items second hand, or perhaps a relative has some hiding in their garage!
- Australian made, family owned company
- Easy to moderate difficulty level
- Moderate prep, and process times of 60 to 70 minutes with minimum supervision required
- No need for refrigeration or freezing to keep foods long term
- A range of recipes available
- Need space to store the equipment in between uses, and a dark, cool pantry or cupboard, with even temperature range, to store all your bottles of preserves
- Takes time – prep of food and bottles, the processing time, cooling down, labelling and storing
- Easy enough process to follow, but does take some time spent learning the essentials
- Cost of equipment, especially if buying new equipment
- Suitable for high acid foods only, using Fowlers Vacola recipes
- Less research and testing information available compared to boiling water bath ‘canning’/ bottling (see note)
Although the company and method has continued to be used since 1915, any information regarding the research into the safety or testing the concept originally is not available. I emailed the Fowlers Vacola company in March 2013, and was given this information from John R Roy,
“I’m not privy to research notes of Joseph Fowler as the company was started in 1915 and I’m presuming that any such info was dissipated over time. The method was based on pasteurisation , where harmful enzymes would be killed , enabling long time preservation of foods. Pasteurization can occur between 72C and 96C The higher the temp the shorter time required. We generally recommend against boiling for an extended time so as not to force liquid/food product out of the jar (especially when jars have been filled right up ), as this can foul the seal. You have this information via US advice on your site. If bottling for show purposes, boiling will also dislodge carefully placed fruit. We would term the type of preserving fowlers employs as the ‘water bath method’. Further Australian information can be found by contacting the CSIRO Food Technology dept.”
Recently I contacted the company again, and found them friendly and accessible when requesting further information (regarding altitude and hot/ cold packing). I can pass that information on to you, as well as referring to The Secrets of Preserving manual (or suggesting you look up What’s Old is New Again). But I suggest for those interested, to contact the company directly (or the CSIRO Food Safety department) if you have questions or concerns not covered in the Secrets of Preserving manual.
You will need:
- Fowlers Vacola electric preserving unit (available as Simple Natural Preserver, or the Professional Stainless Steel Preserver)
- Fowlers Vacola food preserving bottles, with matching size lids, rings and clips
- jar lifter/ tongs (I highly recommend the Ball Secure Grip Jar Lifter tongs, found at Big W or online).
- food funnels (plastic, metal, or collapsible, I use one like this)
- bubble remover, or long skewer (bamboo is preferable over metal), or chopstick
- timer, ruler, clean tea towels/ oven mitts (silicone), labels
It is recommended that you use new rubber rings for Fowlers Vacola bottles each time (bottles, lids and clips can be reused if they are in good condition). Reusing old rubber rings may mean you won’t achieve or maintain a seal.
Fowlers Vacola bottles come in various sizes, and then have accessories (lids, rubber rings and clips) that fit, matched by the diameter of the of the bottle mouth (i.e. size 3 is 3 inches diameter, size 4 if 4 inches diameter). For example:
- Bottle No. 14 (350mls) requires Size 3 lids, rings and clips
- Bottle No. 20 (600mls) requires Size 3 lids, rings and clips
- Bottle No. 27 (850mls) requires Size 3 lids, rings and clips
- Bottle No. 31 (1000mls) requires Size 4 lids, rings and clips
- Bottle No. 36 (1200mls) requires Size 4 lids, rings and clips
Before buying Fowlers Vacola bottles second hand, it is a good idea to check the availability of accessories, especially the rubber rings (which are recommended as single use), in the size that matches the bottles.
You can also buy Fowlers Vacola bottle openers, plastic Snap on lids for storing open bottles in the fridge, and some other specific Fowlers Vacola tools.
Although they are no longer available new, you can also buy second hand stove top Fowlers Vacola preserving units, and can search for instructions in the Secrets to Preserving manual, or contact the company.
Please ensure your equipment and bottles are in good condition before each preserving session. Look for chips or cracks in the bottles, especially around the rim and area where the rubber rings sit. Look for dints or damage to the lids.
No, you don’t have to pre-sterilise your bottles and lids, or equipment, before Fowlers Vacola processing. The processing in the Fowlers Vacola unit sterilises the bottle and contents, killing off any contaminants that may have been in your washed and clean bottles.
Information in the Secrets of Preserving regarding hot packing (hot and cooked contents into bottles), raw packing (uncooked contents into bottles, then hot preserving liquid) or cold packing (cold contents and liquid) is scant. I contacted the company (via message with their Instagram account) and was given this information,
“Fowlers bottles are made from tempered glass, so you just need to ensure you don’t ‘heat shock’ the glass. If what you’re bottling is warm, ensure the bottle is of a similar temperature and your preserving kit water is also similar if you are going to process them in your kit straightaway“.
I can only presume that starting with warm bottles and water means you may find the water in the preserving unit has a higher chance of boiling, and as per instructions in the manual, you turn it off at that point.
“Water should not boil. If boiling occurs within 1 hour, do not allow to boil for longer than 5 minutes. Turn off unit. Allow to stand for rest of the hour. Remove bottles“. (p.13, Secrets of Preserving manual)
To warm up, and keep your bottles warm, you can:
- warm them in water in a large stockpot of water, over low to medium heat
- do a quick/ short run in the dishwasher, and keep the door closed (and the warmth in) until ready. Putting your bottles in the dishwasher is not a way to sterilise the bottles, just to clean and keep warm them.
If using hot contents, remember to put the rubber rings on the bottle BEFORE filling with hot contents! Trying to put the rubber rings on the bottles after they are filled with hot pickled beetroot can be hazardous (ask me how I know!)
TIPS ON APPLYING RINGS
Before filling jars, place the rubber ring in the groove on one side of the washed and clean jar, and using your thumbs stretch it over the top of the jar and let it settle into the groove on the other side. Your ring should be sitting within the groove all the way around the jar now. If it is twisted, run your thumb along the rubber ring, pressing it to make it turn over the right way, or pull the twisted section out from the groove and ease it back to right way. If there is lots of twisting, take it off and start again!
TIPS ON APPLYING SPRING CLIPS
The centre of the top of the lid can be found by the size marking, or some lids have a line across them, to indicate where the clip needs to be situated.
Place bottles on a kitchen bench or tabletop. Do not attempt to put clips on full bottles, whilst holding the bottles up in the air!
Hold the bottle with one hand, using index/ forefinger to keep the lid in place. With the other hand, hold one end of the clip, as per photos, with forefinger to guide. Place the other end of the clip against the side of the bottle furthest away from you, sitting it underneath the rim edge. It holds itself there whilst you pull it back across the lid towards yourself. With a little pressure, use your thumb and middle finger to press it into place on the other side of the bottle. The spring loading means you will feel tension in the clip as you slide it down over the lid and side of the bottle, and snap it into place. If it does not look centred, you can slide or shift it around carefully to centre the clip.
If you live more than 305m (1,000 feet) above sea level, the temperature at which water boils is lower than 100°C, which means there is greater chance the water in your preserving unit will boil within the 60 minute processing period.
Canberra is 577m above sea level (approximately 1893ft). I find in Canberra my Fowlers Vacola unit always starts to boil before the 60 minutes time is up, so as per the Instructions, I turn it off and leave the bottles in there for the remaining time, then remove. But does this mean that the correct temperature was reached and maintained for the required time, in the preserving unit?
In the Secrets of Preserving manual, I could not find information or instructions on whether the altitude of where you live may affect your processing in a Fowlers Vacola Simple Natural Preserving unit (which does not have an inbuilt thermostat like the Professional Stainless Steel Preserver). I contacted the Fowlers Vacola company, who said,
“Water boils at a lower temperature at altitude. In your Fowlers Preserving kit, at 1000 metres this will mean that it may reach boiling point 5 to 10 minutes earlier. This applies to Simple Natural Preserving Kits only. There are guidelines in your recipe book, however as a rule of thumb, turn the unit off once it begins to boil, and allow the bottles to remain in the unit for the balance of preserving time.”
“Switch it off once it boils, if it’s at 50 minutes that the unit boils, leave it switched off for 5 minutes, and then switch back on for the final 5 minutes of processing time.”
BOTTLES NOT ACHIEVING A SEAL, OR LOSING ITS SEAL
Please refer to 10. Bottles Fail to Seal (p. 48 of The Secrets of Preserving, Troubleshooting and Problem Solving section). Also consider that bottles may not seal after processing, or may lose it’s seal during storage, due to several reasons:
- old rubber rings, or rubber ring not sitting in correct position
- old or damaged lids
- chipped bottle rims
- removing bottles from preserving unit and squeezing/ moving the clip (you should use preserving tongs, or use a jar lifter, placed on the glass area, not on the lid or clips)
- moving processed bottles or touching/ tightening the clips, instead of allowing them to sit in one place for 12 to 18 hours
- overfilled bottle, without 12mm headspace – food particles sit up around rim, obstructing the rubber ring, lid and rim of bottle from creating proper contact, during the vacuum sealing that occurs once jars are removed from the pot
- double clipped, which doesn’t allow for air to escape during or after processing, which is required for a vacuum seal
- clip wasn’t in correct place, which means the lid was able to move around and not sit against the top rim of the bottle properly
- didn’t process for the correct amount of time
- too much oil or fat in preserves, which made its way up to the rim during processing
You can try reprocessing the unsealed jars, according to Secrets of Preserving, page 48:
“15. Resealing. A bottle which has failed to seal may be re-sealed providing this is done immediately after detecting the faulty seal and providing the faulty seal has been detected when the clip is removed after the 12 – 18 hour cooling period. Method: Remove the lid and rubber ring. Fit a new rubber ring which has been soaked in warm water for 15 minutes, add additional syrup or selected liquid to contents of the bottle allowing a 12mm headspace. replace the lid and clip and reprocess.”
You can also put processed bottles that didn’t achieve a vacuum seal in the fridge, and use within several days. You can transfer the contents to a freezer proof container and freeze it instead.
Bottles may break during processing due to several reasons:
- temperature changes or ‘thermal shock’ – putting hot contents into cold bottles, or cold content into hot bottles; putting hot bottles into cold water, or cold bottles into hot water
- damaged bottles, that have weak spots from using a metal skewer or knife in them, or chips/ cracks
- old bottles that have weakened from use (especially if they have been used for everyday storage/ lunchware/ freezing etc), or stored in an area that isn’t protected or has temperature fluctuations
Please refer to p.47 and 48 of the Secrets of Preserving manual for information by Fowlers Vacola regarding these issues.
WHY DO WE NEED TO ‘DE-BUBBLE’ BOTTLES BEFORE PROCESSING?
We need to have the right balance of empty space (air) and preserves in the bottle, before processing. The term for the empty space left between the top of the food/ contents, and the underside of the lid, is headspace.
“Leaving the specified amount of headspace in a jar is important to assure a vacuum seal.
If too little headspace is allowed the food may expand and bubble out when air is being forced out from under the lid during processing. The bubbling food may leave a deposit on the rim of the jar or the seal of the lid and prevent the jar from sealing properly.
If too much headspace is allowed, the food at the top is likely to discolor. Also, the jar may not seal properly because there will not be enough processing time to drive all the air out of the jar.” From here.
After filling your bottles, remove bubbles with a specific ‘de-bubbling’ tool, or a chopstick, bamboo skewer or small silicon spatula, and then measure the headspace. Leaving too many air bubbles in the bottles before processing means the ‘headspace’ (or empty space) is actually greater than you realised.
LOSS OF LIQUID
If too little headspace is allowed the liquid or food may expand and bubble out when air is being forced out from under the lid during processing.
Also, air bubbles trapped somewhere in the middle of the bottle, may be forced up during processing, and can end up pushing out some of your liquid (i.e. brine, syrup, water) out of the bottle (siphoning). Your pieces of fruit or pickled veges are then above the liquid line in your bottle, and whilst not unsafe, are prone to discolouring.
PRESERVES FLOATING OR SEPARATING
Fruit and pieces of vegetable may float in the bottles after processing, as there was air trapped inside the preserves.
Another reason is that the pieces were not packed tightly enough, and as shrinkage occurs when heating (as water comes out of the fruit or vegetables), there is more space for the pieces to float.
If preserving fruit in syrup, you may find the pieces of fruit are lighter than a ‘heavy syrup’ and that can also cause floating. You may notice the same issue with sweet chilli sauces!
Sometimes you might notice that sauces or salsa separate in the bottles after processing. This can happen because the pectin in the cell walls that keep the flesh together is broken down, with the pulp and water separating. These elements have different density, the lighter rises, and the heavier sinks.
Floating and separation can be reduced by hot packing, packing tightly, and making sure to de-bubble too. As long as your preserves met the high acidity requirement, you followed the steps and processed for the correct time period as per your Fowlers Vacola instructions, the preserves will be safe to consume, despite the floating or separation.
STORING YOUR BOTTLED PRESERVES
Remove clips, and check seal. Do not store your bottles with clips on. Label, date and store your bottles in a cool, dark, dry place with temperatures between 12 to 15° C (The Secrets of Preserving, p.13). Avoid cupboards next to ovens/ stovetops, dryers or other areas that may have fluctuating temperatures. We created a large preserves pantry in our ‘linen’ cupboard, by reducing the amount of unnecessary stuff in there, and moving blankets to cupboards in bedrooms. Other people with limited cupboard space may use plastic boxes with wheels that slide under beds.
HOW LONG DO THEY LAST IN STORAGE?
“Home bottled preserves keep indefinitely, however prolonged storage will have an effect on nutritional value“. (The Secrets of Preserving, p.13) Peak nutrition can be retained for up to 1 year.
CHECKING THE BOTTLES
Please note, this advice is for high acid preserving. Low acid unsealed or suspect preserves are handled differently.
Visually check the bottle, it’s seal, and the contents before opening. If the lid has lifted or become unsealed, the contents should be disposed of carefully, and the bottle cleaned thoroughly. If there are obvious signs of food spoilage, the contents should be disposed of carefully, and the bottle cleaned thoroughly.
Signs of food spoilage include the presence of mould, or yeast growth, bubbling gases, cloudiness, leaking, fermentation, sliminess and bad smells, or there may be pressure build up under the lid, making it convex instead of concave.
Do not taste the preserves in an unsealed bottle, to see if they are OK. Some bacteria that cause foodborne illness may not have a smell or taste, or have any obvious signs! You may be unwittingly exposing yourself to unsafe food during your ‘taste test’, or worse, the lack of bad taste may wrongly reassure you, and you eat all the preserves and get sick. Bottles that have become unsealed during storage must be presumed unsafe.
Physically check if the lid does not lift off easily, and it requires pressure (from an opener or your fingers) to force it off, then the seal was maintained during storage.
OPENING THE BOTTLE
There is a specific tool available to open Fowlers Vacola bottles. Place it under the edge of the lid, you can feel the rubber of the ring with the tip of the opener. Press the tip of the opener down whilst also lifting the handle up. This will prise the lid away from the rubber ring and the vacuum seal will release. You should be able to do this without dinting or damaging the lid, as it can be reused again.
KNOWING IT IS SAFE TO EAT
Once open, check the contents again, for obvious signs of food spoilage which has affected the smell, colour or appearance. If this has occurred, dispose of the contents carefully, then fully clean the bottle.
A common home preserving concern is that people are not sure how to tell if there preserves are safe. I get it, it took me a while to build my confidence with food preserving. If you followed the processing steps correctly, used high acid ingredients (pH less than 4.6) and achieved and maintained a seal, your product can be considered safe to consume.
STORING AND USING OPEN BOTTLES
Once open, if the preserves are not fully used immediately, you can store them in the fridge, for up to 1 month, depending on the type of bottled preserves you are storing. If you find you cannot use up a bottle in a reasonable amount of time, consider using bottles with smaller volumes to preserve in.
Don’t forget that you can use your bottles of preserves for more than just as condiments (especially if you have half a bottle you need to use up, and don’t want to waste it).
- Sauces can be used as marinades or added to stir fry, pulled meats
- Tomato relish can be used as pasta sauce, pizza sauce, added to casseroles or bolognese
- Salsa and pickled chillies can be added to nacho mince, stuffed vegetables, or Mexican dip
- Fruit chutneys can be added to curries
- Jam or fruit preserves can be used in muffins, cakes, slices or smoothies, or pureed and made into fruit leathers/ roll ups
- Jam can be used in Jam Jar Salad Dressing
- Pickled vegetables and relishes can be used in sauce, mayonnaise, or dips made with cream cheese or sour cream
For Fowlers Vacola you can use Snap On lids, which are green plastic storage caps.
- Gather your preserving equipment, including your Fowlers Vacola preserving unit, bottles, rings and lids, jar lifter/ tongs, food funnel, ladle or large spoon, paper towel, white vinegar, tea towels, timer, skewer or bubble remover, labels. Carefully check over your bottles for any chips, cracks or damage.
- Soak rubber rings in a small bowl of water (for about 15 minutes prior to use). If you forget to do this, it’s not a big problem, it is just a way to help the rings stretch and go on easier.
- Gather and prepare your ingredients. Follow the tested recipe or instructions.
- Wash your bottles and lids in hot soapy water, rinse and drain. Prepare a couple more than you expect to use. Note, if making a relish, chutney, sauce, pickled veges, or jam that will be transferred into the bottles hot, you can warm the bottles in a stockpot of water, whilst making the recipe.
- Apply rubber rings to bottles, by stretching them over the top of the bottle and settling them in the groove. See tips in the FAQ.
- Fill bottles one at a time with prepared preserves or fruit pieces, until all the bottles are filled to the required level, allowing for headspace of 12mm. You can use a food funnel, and sitting the bottle on top of paper towel can make for easier clean up. Fowlers Vacola instructions (p. 11, Secrets of Preserving) recommend packing fruit into liquid to help eliminate larger pockets of air, though other recipes in the booklet say to put the pieces in first, packing tightly, then pour in the liquid.
- Remove air bubbles. Slide a bubble remover, clean bamboo skewer or plastic chopstick between the bottle and preserves to release trapped air.
- Check the headspace allowance of 12mm. Remove liquid, or contents if over this. Add more liquid if under.
- Clean bottle rim using a piece of folded paper towel dipped in vinegar, to remove any food residue or oils.
- Put lid on bottle, evenly over the rubber ring and glass.
- Apply a single clip. See tips in the FAQ.
- Place filled bottles in Fowlers Vacola unit, sitting them on the shelf evenly spaced
- Fill the preserving unit with water, up to the level recommended for the type of unit you are using (pg.13, Secrets of Preserving). Use warm water if the bottles are filled with warm contents.
- Put lid on preserving unit, and for the Simple Natural Preserving Unit, plug in to the powerpoint, and turn on. Start the timer for 60 minutes (or 70 minutes for no. 36 bottles). Do not allow the water to boil for longer than 5 minutes, turn off the unit and leave bottles in for remaining time.
- When the timer is complete, remove bottles from unit. If using a Ball Jar Lifter (as opposed to Fowlers Vacola tongs) do not place the jar lifter around the lid/ clip area when lifting, as the jar lifter may squeeze them affecting the seal, instead place the jar lifter on the glass area of the bottle. Set upright on a tea towel on the kitchen bench. You may need to let it cool down before starting a second batch, or you may need to release some of the hot water and add cool water, being careful that placing bottles into water of different temperature could cause breakages.
- Leave bottles undisturbed for 12 to 18 hours. Do not adjust or touch clips, as this may interfere with the sealing process.
- Test the seals after resting period, by removing the clips and attempting to lift the lid off the bottle. It will be obvious if the seal wasn’t achieved, as the lid will come off (please see FAQ for process of handling jars that did not seal). If the seals are good, clean the bottles by wiping over the jars and lids, wash the screw bands if you like, and you can loosely replace the screw bands on the jars to store.
- Label and store in a cool, dark place (without temperature fluctuations). Keep an eye on the bottles for signs of bulging lids or broken seals.
Gather ingredients and start making preserves
Wash bottles, lids and clips in soapy warm water. Rinse.
Soak rubber rings
Apply rubber rings to bottles
Fill the bottles
Remove air bubbles
Check headspace of 12mm
Wipe the rim
Put lid on
Apply one clip per bottle
Put bottles in to preserving unit
Fill unit with water
Lid on, turn on, start timer
Timer complete, remove bottles from unit
Leave undisturbed 12 to 18 hours
Remove clips, test seals
Label and store
Do not allow to boil for longer than 5 minutes, turn off for remaining time
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