Welcome to Green Week at Apartment Therapy! We’re giving you advice on how to reduce waste, make eco-friendly choices, and explore what natural living really looks like. Check out all of our Green Living content here, and remember—little steps go a long way.

Doing the dishes involves a surprising amount of mental math. Sure, you want to get your plates, cups, and flatware as clean as possible. But when you search for the best soap to clean your dishes, you may also be considering factors like efficiency—like how long the job takes and how hard you have to work to do it. Then there’s cost-effectiveness, and the fact that different cleaning products can have a drastically different impact on the environment.

Lots of people are drawn to solid dish soap as an ideal solution: It’s been said to do just as an effective job at cleaning, while potentially causing less impact on both the environment and your bank account. But does solid dish soap really live up to the hype, or is classic, liquid dish detergent a more reliable option? The answer isn’t simple: It depends on your priorities.

Curious if you should make the switch to solid soap or stick with liquid? Here’s what five people in the cleaning industry have to say about the pros and cons of each.

Natural Cleaning Experts Say:
“As demand increases for zero packaging and plastic reduction, new dishwashing products are coming into the market in innovative forms. While both liquid and bar dish soaps deliver when it comes to cleaning ability, bar soap is minimally packaged and generally lower-waste. Traditional liquid dish soap tends to be more affordable and can last a bit longer, but you can also easily extend the longevity of your bar soap by letting it dry completely between uses. Overall, in terms of waste, bar soap is the way to go. If you’re more concerned about cost, opt for a traditional liquid soap. The good news is, both are just as effective at cleaning your dishes!”

A Microbiologist Says:
“I try very hard to give evidence-based information and not be anecdotal. I am a scientist with decades in this field and I work with a group of scientists at the International Forum for Home Hygiene who all have the same commitment. So what can I say? Using soap or detergent is better than not using it all! But I think it depends on what you are washing up. For example, if you have heavily soiled, greasy pans and dishes, I think that the liquid detergent is better at cutting through the grease and loosening the microbial contaminants so that they get washed off. And for containers or dishes that have been in contact with raw meat and chicken and are likely contaminated with bacteria such as Salmonella, Campylobacter, or E.coli, then I would want to use a liquid detergent because there is the potential for bacterial survival on solid bar soap and the soap dish.”

— Dr. Elizabeth Scott, professor of microbiology at Simmons Center for Hygiene and Health in Home and Community at Simmons University in Boston

A Zero-Waste Influencer and Package-Free Proponent Says:
“At Package Free, we sell both liquid and solid soap. I am a huge fan of both. In my experience, solid dish soap cleans pots and pans just as well as liquid soap, without the environmental cost that comes with most of traditional liquid soap’s plastic packaging. At Package Free, we sell liquid dish soap in bulk at our Williamsburg location, but if you don’t live nearby or have a bulk refill location nearby, a solid dish soap is a great waste free option! I love knowing that our solid dish soap is sustainable and handmade because if something is going on my hands, and where I cook my food, I want to know exactly what’s in it! Plus, it’s super cute on my kitchen counter! Since we sell both options at Package Free, and I live a couple of blocks away for easy refill, I have both. Moral of the story: if you’re close to bulk, go liquid. If you’re far away from refill, go solid soap.”