First tentative steps with hot water bath processing
Posted by Fiona Nevile in Preserving | 23 comments
Photo: Vast pot
I woke up a few nights ago and realised that we had a water bath for processing our garden bounty hanging in the Bee Shed. This is a vast laundry pan with a double base.
I have been boning up on hot water bath canning/bottling. I just wanted to process fruit and tomatoes for the winter. Other vegetables are being pickled, frozen or will be when the Food Dehydrator
eventually arrives from Germany.
Danny was suspicious.
“If you put glass jars with lids on into boiling water they will explode. And you will break your precious Kilner jars.”
“You don’t do the tops up tight so that air can escape.”
What he didn’t know was that was not going to use my precious Kilner/Le Parfait jars. I had done some reading and spotted that the Pear Butter that Suzanne and Georgia made in Chickens in the road was put into jam jars before being water processed (not pressure canned). Also I’d read Rhonda’s (Down to Earth) article on frugal hot water bath canning. She uses jam jars too.
Later on D pushed open the kitchen door to see me filling jam jars with peeled baby plum tomatoes, hot tomato juice and a good dash of lemon juice in each – the latter advised by Jackie.
His eyes swept over the jars.
“You can’t do that! They’ll explode!”
“But I’ve seen jam jars being used on the Internet.”
He looked quite white.
“They’re good sites. Not bomb making ones. You put the lids on but not very tight so air can escape. Anyway the pan has a lid if they do explode.”
I was attaching my jam thermometer to the side of the bubbling abyss so as to check that I had the right temperature.
“Well I’m staying upstairs until they’re done.”
Quite a canny ruse as this meant they I had to make supper.
Danny refused to enter the kitchen and chilled beers had to be passed over the threshold into the safety of the sitting room. My 500ml and 250ml jars of tomatoes were submerged in the water bath for an hour. By the end even I was getting a bit jumpy and keeping my distance from the cauldron. Finally the timer trilled and I was able to lift the jars out onto a towel to cool. The jars hissed like mad as I lifted them with my nifty tool. Once the jars were out and resting, I tightened the lids firmly.
As we ate our supper we were entertained by a chorus of pops as the seals compressed down.
If you are going to try hot water bath processing make sure that you bone up on it very well before hand. Vegetables, other than tomatoes or pickles and chutneys, need to be pressure canned as they can be prone to developing the spores that cause botulism if not canned/bottled correctly. Meat and fish also require pressure canning. Pressure canning takes far less time and uses less energy. You can buy pressure canners in the UK for around £100.
Useful links:
Down to Earth canning instructions
Allotment.org.uk detailed canning intructions inluding tables for weights and temperaures
Pick your own Farms.org.uk masses of information and canning suppliers
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I’m desperate to know if ordinary small jars with screw on lids can be water bathed safely as I want to make some apple sauce and my recipe states to process in a water bath for 15 mins. Could I use my maslin pan to do this as I dont have a water bath. I don’t have a lid for it but when making chutney in it I put an old metal tray on it which I have covered in tin foil. It doesnt fit exactly as the pan has a pouring lip to the side. So 2 questions really….can I use small screw top lid jars for my sauce and does if have to be a pan with a tight fitting lid to do the boiling? I know I have to protect the jars – Pam Corbin of River Cottage suggests standing them on a folded tea towl in the pan.Thanks for any advice.
Most commercial screw-top jars can handle the heat; the problem is that if you don’t have unused lids of the exact right size, they won’t seal, so you cannot safely store whatever you are making without refrigeration (especially something like applesauce that is not very acidic). The point of the boiling water bath is to ensure that you have killed off as many of the bad bugs as possible, inside & out, & that the lids will seal (which they will not, if they are being re-used). You can use any large pot — I use old nonstick ones that have gotten scratched (since you don’t have to worry about the coating or whatever is under it getting into your food). Any rack that will fit into your pot will do fine if it keeps the jars off the bottom. (In desperation I have used crumpled aluminum foil nests, scrunched up coat hangers, etc.) You need enough boiling water in there to cover the jars completely & then some (an inch or so above the top); I usually cover the pot while bringing it up to a boil (before putting in the jars) b/c it’s faster, & cover it partially once they are in (so that the water doesn’t boil over). But again, if you do not have fresh lids, you are probably better off boiling the empty jars in advance (to sterilize them), filling them, & then lidding them & keeping them refrigerated (& eating the applesauce soon!). Hope this is of some use. Applesauce is not very acidic (which is why your recipe calls for such a long boiling-water bath), so you really have to be careful; without a perfect seal, you run the risk of mold & worse.
Ooops—should read, “*For jam,* while other bacteria or fungi could possibly be a problem without waterbathing, botulism isn’t.” Not true for veggies or other low acid(high pH) foods!!!
Late reply, but mold can lower the pH of jam to where botulism can grow, unfortunately, & as you say, the spores are very tough. The water bath & a good seal should eliminate the risk of mold.
I guess this is an old thread, but I was investigating this very question and wanted to share what I’ve found.
According to WHO, “The toxin is destroyed by normal cooking processes (heating at >85?C for five minutes or boiling for a few minutes). Clostridium botulinum will not grow, and therefore the toxin will not be formed in acidic foods (pH less than 4.6). However, the low pH will not inactivate any preformed toxin.” So–according to my search, the pH of jam is between 2.8-4, well below the pH that botulism can grow. Plus, the heat from making the jam will destroy the toxin, so all good. The spores might still be present, but even commercial heat pasteurization might not kill those puppies so not really an issue.
Conclusion…while other bacteria or fungi could possibly be a problem without waterbathing, botulism isn’t.
Ummm. Generally, sealed jars of jam can be stored on a shelf for a year or so, no refrigeration needed.
Oh I am getting confused!! 🙁
I have just been sterilising my old and re used jars in the oven – then pouring my grape jelly in – sticking the lid on – waiting for it to ‘ping’ then popping it in the fridge. Am I going to poisen everyone? And how can I tell if it has botulism?! LOL……
Hi Dawn
I’m doing more and more water bathing and it seems to work well. A cooked warm jam would only need 10 mins after reaching simmering point.
Having just started making jams and chutneys, my daughter and I made spicy pear jam today and the recipe said to use a water bath…..we put the lids on tight to the jars and maybe it was beginners luck….all the jars came out intact. It only said to submerge for 10 mins in the boiling water.
Hi Kate
Your comment made me smile. The sort of ghastly thing that is so awful it’s funny in the end.
One particularly miserable winter week I was at the library and came across a book on the history of food preservation. It was fascinating- and hilarious. I know I shouldn’t have laughed out loud at the accident in the 19th century when someone was killed by a turkey, or parts of a turkey, emerging at speed from an early experiment with tin canning, but I did…the book is ‘Pickled,Potted and Canned,how the art of food preserving changed the world’ by Sue Shepard.
Hi LindaM
Thanks so much for your advice and excellent link.
Our pan has a removable extra layer (to stop clothes from scorching I think) and this works well.
I don’t know about you but I’m having great fun with this.
Danny keeps asking, ‘When can we actually eat them?’
Hi Paul
Ahhhh great point. Thank you.
Fiona, thanks for making me laugh today:) I am a new canner and have thought of many similar “what if” scenarios since I started and so the laugh was at myself too. One thing you don’t mention so I don’t know if you did this, is using a rack of some kind on the bottom of the water bath. A wire cooling rack will do just fine. This is to prevent bottles from breaking. Don’t let them touch each other either! If anybody is interested in learning more about American style canning, then the place to go is this link: http://www.uga.edu/nchfp/
It’s the National Center for Food Preservation and has lots of current instruction and some recipes plus an online class which is free.