Week 2 02/12/16: Fermented Milk
Hello awesome fermentation students!
Thanks for an awesome class this week! I hope you all had lots of fun learning about fermented milk and tasting kefir & Yakult! :)
- General pattern of fermented milks:
Heat to kill off competing microorganisms
Cool, so you don’t kill off your wanted microorgs
Inoculate with wanted microorgs
- Leave it out to ferment in a warm environment, until thickened and tangy to your preference! :)
- Fermented Milk PPT
What are kefir grains?
Kefir grains are a combo of lactic acid bacteria + yeasts in a matrix of protein, fats, and sugars (aka SCOBY = symbiotic colony of bacteria and yeast -- this is also found in kombucha!)
In one culture of kefir grains, you may find bacteria strains - lactobacillus brevis, streptococcus thermophillus, lactobacillus casei, lactobacillus helveticus, lactobacillus delbrueckii & yeasts - candida maris, candida inconspicua, saccharomyces cerevisiae.
Of course, strains of bacteria and yeasts present differ from one culture of grains to another!
Kefir grains (or kefir SCOBY) is a culture that has been propagated and passed down for generations, so it’s nearly impossible to grow a strong enough strain at home DIY-style (as you can tell by all the cultures listed above!).
From The Journal of Dairy Science, “Despite intensive research and many attempts to produce kefir grains from the pure or mixed cultures that are normally present in the grains, no successful results have been reported to date.”
Luckily for us, kefir grains, given adequate nutrition and tolerable environmental conditions, can theoretically live forever! :)
- Where can I get kefir grains in Berkeley?
To find kefir grains, you can check out local health stores like Three Stone Hearth or a local home fermenter and ask if you can have some of their grains! They are also available online.
Origins of kefir?
North Caucasus Mountains
Earliest documentation of it was in the 19th century
- Today, kefir is the most popular fermented milk in Russia!
- Can we use a bit of pre-made kefir as a starter instead of kefir grains, like yogurt?
- Yes & no -- it all depends on the health of your pre-made kefir. You could get 3-4 successful batches of kefir using pre-made kefir as a starter instead of kefir grains or 0 successful batches. It’s a gamble!
Give it a try!
1) Mix 1 tbsp kefir/cup of fresh milk
- 2) Store at room temperature for 12-24 hours, or until thickened
Vegan Fermented Milk
- Find Hailey's pictures from class here!
NEXT WEEK’S TOPIC: Kombucha & Jun!
Student Weekly Presentations: Food of Cultural Importance (Required Assignment/Participation Grade)
Each week 3-4 students will present on one food item (does not have to be fermented food) for 2 minutes that is important to their identity, family traditions, or cultural background.
View your presentation dates here!
ABSENT STUDENTS: I have added you to open spots that were empty. Review and notify us if you have any conflict during those dates.
Field Trip Sign-Up!
Takara Sake - Saturday, 3/12 @ 1 PM
For more info & to sign up, click here: http://goo.gl/forms/1JI5U7jjgi
Sign up by Thursday, 2/18, 11:59 PM
Three Stone Hearth - Friday, 4/1 from 9-3 PM
***If you sign up for this field trip but do not show up it will count as an absence. If you have a very good reason for not being able to make it, please notify us at least one week before so we can inform the host. The host works hard to accommodate a large group like ours, so let’s be courteous and respectful to them as well. :) Remember that you are allowed a total of 2 absences to pass the class.***
Can’t wait to see you all next Wednesday, 2/17!
Agnes, Hailey and Vicky
Fermentation: “Culturing” Your World DeCal, UC Berkeley
Wednesdays, 6-7 pm
Location: 2030 VLSB