Our Story

Hello! I am Mary-Thea Brosnan, owner of Kerry Kefir

Mary-Thea Brosnan | Kerry Kefir | Hiking

I love the great outdoors, something I only discovered in my late 20’s. I love the mountains, I love the sea and I love everything about nature. I also love my dogs, Ben and Obie. Two beautiful golden retrievers with completely opposite personalities.

After 14 years living in Dublin, I moved home to Castleisland in Co. Kerry in October 2018 to start Kerry Kefir. I continued to work part-time as an Optometrist (I have a BSc in Optometry) before going full-time with Kerry Kefir in January 2020. I started the business in my parents’ kitchen but I soon moved to a converted truck container behind the house.

For the first year, I sold directly to customers in Castleisland but Kerry Kefir is now stocked in SuperValu stores and independent retailers around Kerry.

Having suffered from digestive issues for years, I was prescribed tablets to be taken before every meal for the rest of my life.

I spent years looking to help my symptoms through diet until a nutritionist advocated milk kefir, a fermented milk beverage packed full of beneficial bacteria and yeast for your gut health.

I sourced kefir grains and started making it myself. Within a week, the kefir milk had made a huge difference to my symptoms. I couldn’t believe it! 

I noticed that none of the milk kefirs on the market were made in the traditional way using kefir grains but were instead using powdered, lab-manufactured cultures. So I decided to create a premium product using the living organisms to produce the most natural form of milk kefir as it was traditionally made.

Banna Beach Sunset | Kerry Kefir

Why Choose Us

Traditional Kefir Grains | Kerry Kefir

Traditional Kefir Grains

We are the only milk kefir on the Irish market making milk kefir the traditional way, by using live kefir grains

Handmade batches | Kerry Kefir

Handmade batches

Every single batch of Kerry Kefir is lovingly handmade, so that you can enjoy your traditional kefir straight from our kitchen to yours

Environmentally Friendly | Kerry Kefir

Environmentally Friendly

Kerry Kefir is bottled in glass bottles. The bottles can be returned to us so we can re-use them multiple times

Our Process

Our Awards

Best Start Up

Dairy – Milk (Other)

Food Production

One to Watch

Food & Drink Startup

Listowel Food Fair - Food Hero Award 2023

Food Hero Award

Reach Us


Mary-Thea Brosnan
Tralee Road,
Co. Kerry




M-F:  10am – 3pm
S-S: 9am – 2pm

Get In Touch