Pectin effectiveness post expiry

July 10, 2014 6:36 AM

Hey, I'm about to make some tart cherry preserves. The (no sugar needed) pectin I have readily available is "best by" 2009. Ingredients on the box: dextrose, fruit pectin, locust bean gum, xanthan gum. Does pectin break down or will this be OK? I ask because I have found conflicting information online. It's trivial for me to get some new pectin, which I will probably do, but I was just wondering.
posted by Stewriffic to Food & Drink (6 answers total)

My SO just made some jam with old pectin, and it didn't turn out well. Well, more accurately, it turned out delicious, but runny to the point that we were basically drinking it instead of spreading it on things.
posted by Etrigan at 6:42 AM on July 10, 2014

Official word from the National Center for Home Food Preservation: "Purchase fresh fruit pectin each year. Old pectin may result in poor gels."
posted by MonkeyToes at 6:46 AM on July 10, 2014 [2 favorites]

Response by poster: OK, as I had suspected, this won't work, and I'll buy new. However, does anyone know the science behind the pectin not working after a fashion? In layman's terms?
posted by Stewriffic at 6:50 AM on July 10, 2014

Best answer: A quick search and it looks like high storage temperature, bacteria, and fungus can all degrade pectin. If it's open, fluctuations in humidity might have gotten it a little bit damp, and it looks like an acid environment can cause it to break down too (not sure what you have, but I was jamming this weekend and noticed there was citric acid in the pectin I was using.)

If you have some fruit juice or sugar water in the house, it wouldn't take much work to microwave an appropriate volume of pectin with a quarter cup of liquid until boiling and see what happens when it cools.
posted by tchemgrrl at 7:01 AM on July 10, 2014 [1 favorite]

If you decide to get new pectin and you don't make jam frequently, I'd recommend Pomona's. It doesn't expire and is totally reliable.
posted by Beti at 9:11 AM on July 10, 2014

Response by poster: Yeah, seeing the Pomona's lack of expiry date was what first confused me.

The finished product, and it did gel, with the new pectin.

Thanks, all!
posted by Stewriffic at 12:01 PM on July 10, 2014 [3 favorites]