I buy it in plastic tubs, but I leave it open on the table next to the washer. It has never hardened. I wonder why? I don't use it very often so it has been in the basement for two years. Perhaps transfer it to a plastic tub and seal it?

I use it primarily when I give the kitchen floor grout a good scrubbing. I hate that floor.

On the other hand, my baking powder, kept in the can in a kitchen cabinet, turns rock hard.

I buy the box at Costco and fill a 4-cup Glad container that I keep sealed up by the washing machine. And I keep a clamp (cereal or chip bag clamp) on the plastic bag within the box. Have never had it harden.

BUT.... I do the same with the big box of dishwasher detergent, keep the Glad container under the sink. That box had hardened into a rock, which takes a hammer to chip apart. Both the dishwasher soap and Oxyclean are stored in the same area in the garage.

I have no problem with my boxed, powdered detergent, only with the Oxyclean. I was going to ascribe the difference to our humid climate and the presence of anti-caking components in commercial laundry detergents, but you've both dispelled that one. Hmm, curiouser and curiouser . . .

My large container (plastic bag in a box) of oxyclean hardened too. I have used it up and now plan to buy smaller containers of it that come it the plastic containers with a lid.

My large container (plastic bag in a box) of oxyclean hardened too. I have used it up and now plan to buy smaller containers of it that come it the plastic containers with a lid.

1. I would have used a box grater to reduce the hardened chunks to granules again, then repacked into quart or pint canning jars and vacuum-sealed them shut with the FoodSaver and the jar sealer to prevent exposure to oxygen and moisture. Moisture activates the ingredients enough to alter it from free-flowing to a "brick". I've had Washing Soda turn to a brick in a box, so now I store it in vacuum-sealed canning jars as soon as I get it home from the store.

2. The first time you open a new container divide the large amount into smaller air-tight bags/containers. Fill them as full as possible to displace air-space in the containers. Oxygen-free storage would be best, so if you happen to have a FoodSaver with a jar attachment, you could vacuum-seal the Oxyclean in jars. In jars it would remain free-flowing, but free from oxygen and humidity.

3. I use Charlie's Soap (powdered detergent) by the bucket. The first bucket (5-gal., 1,280 loads) purchased 11-2007 lasted 3-years. It comes in a smaller bucket now - 32# - 1,000 loads. I put a layer of paper towels on the top of the powder and a moisture absorber (silica gel packet - available from Amazon.com in several different sizes) on top of the paper towel, and stored it in the basement. I refilled a small container (one of their 80-load plastic containers) for use in the laundry room. I replace the moisture absorber occasionally, especially when the moisture is high in the basement in the spring/summer.

I use buckets of powdered milk and do the same thing with them - filling a #10 can for use in the kitchen. A bucket will last us approximately one year. Without the paper towel and moisture absorber in the top, it would get hard.

-Grainlady

Wow! Thank you. I use C's Soap, too, but had forgotten my issues with it since DH used last batch at the boat. I do have a Food Saver (used for venison recently) and have not used jar vacuum attachment yet . I do have many canning jars that my jam giftees have been thoughtful enough to return to when they finished eating the jam.

I buy a big box from Costco also. I open the bag and pour about half into a large glass jar with a lid. The other is sealed up well in the bag until the jar is empty. Works well for me. The jar is about a gallon size and used to have pickle relish in it.

Okay, so I followed Grainlady's advice to grate the Oxyclean cake (microplane grater) and put the soap into a one gallon penny candy jar, the top of which DH modified to form a tighter seal. I also added a silicon desiccant to the works. So far, so good.

This post was edited by kitchendetective on Sat, Dec 28, 13 at 18:44