How much headspace did you leave in the jars and were these very old 2 piece lids or new ones?

Assuming proper headspace was left, the jam would never come into actual contact with the seals. But honestly, even if it did, the sealing compound is a neutral silicone compound, not rubber, which shouldn't transfer any odor or flavor to the product. I have never had it happen in 40+ years of canning. I'd be more likely to suspect something wrong in the jam recipe itself.

But if they were old lids - several years - I suppose it is possible that the compound might be breaking down.

Dave

Doubt that either Dave, found some wide mouth ones in the basement this summer in the boxes, they don't even make that design anymore.
Sealed like they were new.
I had one box of rubber rings that dried out for the glass top bailed ones, but you couldn't use those, brittle and broke.

I also am wondering if there's a cause other than the lids. I've used the old (very old) rubber-lined lids, including a 50-year-old box I retrieved this summer and have never experienced any rubbery taste.

As Dave mentioned, new lids are silicone, so they aren't going to impart any flavor or odor.

Carol

could the berries have been overcooked and/or slightly scorched?
kay

How old are the lids? Hot water, almost to the simmering should be the water the lids are in. I have never had that silicone compound smell. Its food grade and isn't supposed to give off any sort of smell at all. Were your jars cleaned and thorougly rinsed out? Scorching can happen too. They still sell the rubber rings for the bail type jars. But there you can't easily tell if there is a vacuum. Very old lids like 50 years or so, can rust badly, and back then it was a rubber based compound. So keep an eye on them.
At one point some years ago, my mom had lost her sense of smell and taste, as I have that now too. Everything tastes terrible, bitter, odd, and most anything awful other than the item your eating.

Thanks for your ideas.
They were brand new lids...I left about half an inch of headspace (maybe a little more), so it's probably not the silicon seal leaching into the jam.

My guess is that I cooked the berries for too long, hoping to get to that magical set point!! Is it better to cook the strawberries down without sugar for a while before adding the sugar, or is strawberry jam one of those things where you have to use pectic if you want a thick set?

If anyone has a recipe for strawberry jam (with or without pectin) that works really well and gives a nice thick jam, I'd love to have it!!! Before I ruin another batch...

At any rate, I'm glad to know that the silicon seal material is probably harmless!!

Hannah

You add the pectin first and bring the mix to a boil, then add sugar or sweetner. Not the sugar first.

Are you making straight strawberry jam , full sugar or low/no sugar or artificial sweetner?

Pectin will require sugar if you use regular pectin. The sugar is usually added at the time your heating the strawberries. If you were to try and make a jam without added pectin, a lot more sugar would be needed as well as a thermometer to see the temperature it reaches to set a gel. Strawberries have only a little pectin naturally so they would need some help from either added pectin, or something high in natural pectin like cranberries, or apple skins cooked down, or even cooking down lots of apple cider. If you don't wish a very sweet jam, there is always Pomona pectin, which will even gel water..

All kinds of strawberry jam recipes here that a search will pull up for you. Several in the discussion on strawberry jam just a couple of discussions below yours. And most all the various pectins come with a recipe included in the box if you decide to use pectin.

Link below is to the basic recipe using pectin provided by NCHFP. They offer several others - with and without pectin too.

Dave

Here is a link that might be useful: NCHFP - Strawberry Jam recipe

It's a myth that traditional no-added-pectin jams require more sugar. In fact, it's just the opposite. Ironically, it's jams with added commercial pectin that require the greatest amount of sugar. The plus with such jams is higher yield. The minus is a blander flavor due to a lower proportion of fruit to sugar than traditional preserves.

It's perfectly possible to make fine strawberry jam without added commercial pectin or any other amendments, but it's easier in the Pacific Northwest where the berries have a different ratio of acid to pectin due to the cooler climate.

I never use commercial pectin in my strawberry jam and I use far less sugar than would be required by Sure-Jell, for instance.

As Dave mentioned, several previous threads have posted recipes for strawberry jam/preserves.

Carol

Your right Carol.

Best practice I find for newbie canners is not a food science course, but follow instructions like Dave provided, or pick up a box of pectin at the store and follow the instructions carefully.

Just as in baking, you have to start somewhere, better to to know how to crack the egg first, then learn butterfat ratios for the frosting.

better to to know how to crack the egg first

Amen. ;)

Dave

I agree, Carol, I make all my jams without pectin and I cut the sugar way down and still get a set. They do have to be cooked longer and watched more carefully, but they taste much more like fruit than they do like sugar.

Annie

Thanks everyone!

I'm looking forward to cracking my next egg...

Hannah

Hi - I noticed the same. I made jam in several jars, using both orange and white rubber bands. I experienced rubber taste in the jam with orange rubber bands only. I will only use white once in the future.