Still reeling from a string of food-borne illnesses in 2015, Chipotle is making a big public push to alert customers to its improved safety measures.

The Wall Street Journal reports that the new Chipotle marketing campaign is focused on bringing customers back to the fast casual restaurant by highlighting the company’s steps to increasing food safety at restaurants in recent months.

The ads employ an “open letter” format, with CEO Steve Ells elaborating on how the company has turned things around in the kitchen.

Since it was involved in norovirus, salmonella, and E. coli outbreaks that sickened hundreds of customers last year, Chipotle has revamped several of its standards kitchen process.

For example, the company moved preparation of some ingredients to central kitchens so they could be tested for pathogens, added lemon juice to chopped vegetables, and revamped meat handling: raw chicken was to be marinated in plastic bags, and steak would be tested before being sent to stores.

Ells’ letter also directs customers to the Chipotle website where they can find a video — featuring Ells himself — that actually shows some of the food safety measures in action. Scenes show the “food safety advancements” Chipotle has undertaken from “supplier interventions” to “advanced technology” like the “kill” steps that stop pathogens, such as blanching vegetables and washing lettuce, and the off-site sous vide — a slow-cooking technique — preparation of steak.

Despite the changes, WSJ reports that some customers who returned to the company have left again, finding the quality of ingredients suffered from the measures.

That of course, is likely why Chipotle continues to court its former customers with things like giving away free food — to kids, college students, and others — launching limited-time promotions, and a temporary loyalty program.

Those measures don’t seem to be helping the company rebound. A survey recently found that 25% of former customers have stopped going to the restaurant or have been stopping by less frequently.

Earlier this month, activist investor Bill Ackman’s Pershing Capital Management took a 9.9% stake in the company as an attempt to turn its sagging sales around. This week, the company said it would put more focus on its European business.

Chipotle Explains Food-Safety Practices in New Ad Campaign [The Wall Street Journal]

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