One of the many advantages of wool is the fact that it doesn't retain odor, and can be used many times between washings without getting stinky. I usually just hang my wool sweaters and jerseys to air out and only wash them when they are actually soiled, or if they do start to smell.
This feature makes wool an ideal fabric for travel.
The (slight) disadvantage of wool is that when you finally do need to wash it, it should be handled with care, as it were.
Wool naturally contains lanolin, a waxy substance secreted from the glands of wool-bearing animals. Lanolin helps protect their skin and keeps their wool soft and supple. Lanolin also repels water, making wool good in rainy weather. Detergents strip out the protective lanolin and can damage wool fibers, causing wool garments to full - puff up and get fuzzy.
There are a few well
known detergents (Woolite among others) that claim to be made for wool.
They may be milder than other detergents, but detergent really should be avoided if you hope to keep your woolies looking good for years.
We recently started using a lanolin-based product, Kookaburra Wool Wash. It is designed specifically to protect and extend the life of wool garments. Rinsing is optional, simplifying hand-washing and shortening the machine wash cycle. According to Kookaburra's recommendations, we just run (only) the rinse cycle (on our front load washing machine) putting the wool wash in the fabric softener dispenser.
A reader here just recommended Eucalan, which appears to be very similar to Kookaburra Wool Wash. I now have a bottle of Eucalan on order, and look forward to trying it as well.
Finally, remember that dryers are the enemy
of wool. Woolies should be dried flat or hung on a rack or clothesline out of direct sunlight and away from any heat source.