Wool is naturally self-cleaning, the outer surfaces of the fibre pushing dirt down and off itself. It's naturally anti-bacterial and neutralises odours too... so after wearing, the best thing to do is to hang your wool to air.
We strongly recommend not washing wool fleece at all, as it is so delicate.
Read what Engel has to say about caring for your new clothes.
"You don’t need to wash our products before wearing them for the first time. After the knitting process, our fabrics are washed to rinse out any excess dye residues, in the first place, and secondly to remove knitting oils and dirt.
Our products are all made using 100% ecologically sound methods and have no chemical finish. And we never make use of dyes that could be a health hazard or textile finishes which could cause skin irritations, for example, or harm the environment during or after processing. We are not allowed to do this under the strict manufacturing criteria with which we must comply to obtain the IVN BEST or GOTS certifications for our products.
We basically recommend that you wash our wool and wool/silk fabrics as little as possible. Wool regenerates in oxygen-rich air of its own accord and so it can also just be well-aired."
Engel's organic Merino wool fleece is a very soft fabric and is easy to damage when washing. Extreme care must be taken if you do decide to wash it. Engel recommends hand washing as follows.
In the event that you do decide to wash your fleece, use a detergent designed for wool which protects and replenishes the wool's natural oils. We recommend one of our liquid wool shampoos in our fabric care section here.
To hand-wash your organic Merino wool, dilute your wool detergent in cool water, max 30C (lukewarm only, should feel coolish), in a bowl. For heavily-soiled areas, use a little gall soap on your woollens first, testing on an inconspicuous area first.
Add your woollens to the bowl, gently stirring and squeezing the detergent through. Rinse using water at the same temperature, otherwise, your wool will be subjected to "shock" and might felt up. So lukewarm/coolish at 30C again.
Things not to do! Don't wring, soak, brush or rub vigorously as the wool fibres may be damaged and your garment felt up a little and shrink. Just squeeze the water through.
To dry, gently squeeze water out and wrap your wool clothes in a towel to remove the excess water. Air-dry naturally avoiding direct heat. So, hanging on a drying rack over the bath is good, or on a clothes horse. Mine often end up over the back of chairs or on the washing line in the shade (I haven't had a problem with the heat of the English being too hot, yet, but direct sunlight is not good for wool).
Re-shape while still damp.