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Sour Milk School

With Trevor Warmedahl

At First Rain Farm in Nevada City, CA
April 22nd-26th 2023


Trevor Warmedahl is a nomadic cheesemaker, herder, writer and educator who has created this workshop The Sour Milk School after a decade spent as an artisan cheesemaker in the USA, working for small and large producers, while also living on farms and caring for livestock. From 2019 until the present he has been traveling and documenting the dairying, grazing, and cheesemaking practices of pastoral people in various countries including Mongolia, Tibet, Italy, Austria, Spain, Albania, Slovenia, and Georgia. He has also spent a year in between travels to work with various types of grazing systems on farms in Vermont and California.

The Sour Milk School is a mobile educational project that collaborates with fermenters, chefs, dairy farmers, communities, and cheesemakers to offer workshops in which methods of natural cheesemaking and milk fermentation are shared. The focus is on working with fresh raw milk, its microbial ecology healthy and intact. By cultivating the microbes indigenous to this milk, starter cultures can be cultivated to make essentially any style of cheese. We will be using fresh goats milk from our farm that will be milked fresh daily and we will be sourcing fresh raw cow's milk from a friend nearby who keeps dairy cows.

Areas Of Focus

  • What factors lead to good cheese milk, how milk microbes behave, which methods are available for steering the fermentation.

  • How to make and use rennet and plant coagulants. How the choice of coagulant shapes the cheese flavor and texture.

  • By seeing, smelling, touching, and tasting the process, students are participating with microbes and fermentation in a multi-sensory experience. We will use measuring tools (pH meter) to begin to train the senses, as a foundation that can lead to students becoming competent makers.

  • Methods of making lactic (chevre) and stretched curd styles (mozzerella), to be aged or eaten fresh, Feta, and Ricotta. The specific styles may vary, depending on available milk, and climate. We may also make Tomme or Halloumi.

  • What common tools and DIY equipment can be used to make and age cheese, natural materials for cheese shaping and storage.


Over the five days students will learn how to make a clabber starter culture, yogurt, kefir and six cheeses: 

  1. Feta

  2. Mozzarella

  3. Fresh lactic - such as fresh goat cheese (chevre)

  4. Aged lactic with Geotrichum rind in glass jar

  5. Caciocavallo - an aged version of Mozzerella

  6. Ricotta

Core Curriculum


Students will build a base knowledge about the constituents of milk, how microbes ferment milk, and what coagulation is. We focus on sourcing the highest quality, fresh raw milk. Great cheese starts on the farm.


The crux of the course is sharing methods of making and maintaining starter cultures from the microbes indigenous to healthy raw milk. Essentially any general category of cheese can be made from clabber or kefir.


The workshops are geared towards those who want to make cheese in their homes, on farms, or in restaurants. The methods demonstrated empower students to make and age cheese without a lot of expensive equipment.

"What I hope to instill in students is that cheesemaking and other fermentations are craft as well as science, and that cheeses have methods rather than recipes. Once you understand the method, you tweak the make to create a custom process that works for your milk and desired goal, and adjust this process day to day as the variables shift. Good cheese milk tends to vary seasonally, and it is the task of the maker to predict these trends and find ways to compensate." Trevor


"Underneath the science and concrete methods is a philosophy of how we choose to interact with microbes, and view our relationship with food, dairy livestock, and landscapes. This is inspired by a paradigm shift happening in microbiology and health, as it is revealed that microbial life is the basis of human health, as well as that of soils and ecosystems. By observing and steering the succession of organisms in and on cheeses, we are healing the wounds caused by the futile attempt to control or eradicate microbes. By working with and propagating milk microbes, we are learning to reclaim a relationship of participation with them, and with life in general."  Trevor

Disclaimer: In these workshops Trevor will discuss the slaughtering and butchering of young livestock, and the use of their stomachs to make rennet. He will use animal rennet to make cheese, and possibly discuss or demonstrate the use of plant coagulants such as thistle. It is a major part of my philosophy that there is no vegetarian milk or cheese. If you are uncomfortable with these topics, the workshop may not be a good fit for you. We are planning to slaughter a young goat to demonstrate how how abomasums are prepared for rennet and you can be a part of that process if you would like in whichever way feels comfortable for you. There will also be options throughout the week to observe us milking the goats and setting up moveable paddocks on our pasture. 

Workshop Logistics


Cost of the workshop: $800

What is included: Five, six hour days of class, tea, coffee, snack and a delicious organic and local lunch catered by our friends at Purdon Studios!

Time of workshop: The workshop starts on Saturday April 22nd and ends Wednesday April 26th. Each day you will arrive at 9:30a.m. and class will start at 10a.m. We will break for lunch from 1-2pm and the second class block will be from 2-5pm.

Lodging: The farm is located just a few miles from downtown Nevada City and there are many local lodging options to choose from. We do have camping spots on the farm as well so feel free to email us if you are interested in that option.

Class size: between 20-23 students so space is limited! 

We will be able to offer some students a discounted price based on needs, due to donations from The Nevada City Farmer's Market & Three Forks Bakery and Brewery. Inquire below on the registration form and we will email you regarding that possibility.

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