Are their differences in traditional and commercial kefir?
This is the second part of the feature, you’ll find part one here.
Despite my scientific training, regular followers of my blogs will have realized I have an established scepticism for extravagant scientific claims. I am a fan of science generally but feel the need to maintain a discriminating eye and treat each scientific claim on its merits. However a recent study into the relationship between kefir and obesity has been worth a closer look.
In a research paper titled Traditional kefir reduces weight gain and improves plasma and liver lipid profiles more successfully than a commercial equivalent in a mouse model of obesity, Bourrie, Cotter and Willing found that kefir appeared able to meditate metabolic health. This study compared the ability of traditional with commercially produced kefir to mediate mouse weight gain, plasma cholesterol, and liver triglycerides. Four traditional and one commercially available kefirs were used in the experiment. Commercial kefir was shown to have no beneficial effect whilst two of the traditional kefirs demonstrated a reduction in the rate of weight gain and increase in blood cholesterol. This was (as far as I know) the first ever study comparing mass produced with traditionally produced kefir, so the research must be regarded as preliminary. It was a study with mice so the extent to which results can be generalised to humans is uncertain.
The research concluded that when also considered in relation to the modulation of the gut microbiome, traditional kefir has the potential to mediate obesity through the improvement to metabolic dysfunction.
The report also explained that different forms of traditional kefir do not generate identical microbial populations. It is assumed that this could be linked to variable health benefits. Further that whilst Lactobacillus, Lactococcus, and Leuconostoc would be expected to be found in most forms of kefir, acetic acid bacteria was not found in a majority of commercial products. Research has also suggested that traditional kefir possesses highly complex fungal communities (including, S. cerevisiae, Pichia fermentans, Kazachastania unispora, and Kluyveromyces marxianus and lactis) not always found in commercial products.
In conclusion, three take home points:
This is preliminary research, it’s early days!
Traditional kefir may support improved cholesterol and fatty acid metabolism.
Traditional kefir appear to offer a much greater microbial diversity to the host than commercially produced kefir.
Having been experimenting with DIY kefir for a while, I thought it was time to share some of the key points we have discovered. This is not an exhaustive guide, follow this link for more general resources. The first thing to consider is that kefir is created by fermenting bacteria, therefore you need to follow reliable instructions. Our ten point guide contains tips that may help you on your way to a more positive experience.
Decisions, decisions, decisions: Kefir can be made using powdered culture or live/dehydrated grains. You can also use a range of liquids to create kefir, milk, water, juice, coconut milk etc. There are subtle differences in how you approach these different processes. Think about it before you start.
Cleanliness: Given that you are going to be growing bacteria you do not want to introduce anything that will pollute or taint your product. Make sure everything that comes into contact with the kefir is as clean as possible.
Quality: I generally aim to use good quality milk/juice/water in order to have the best quality product.
Water: Chlorinated water (tap or bottled) is generally felt to be unsympathetic to both the grains and the product so aim to use filtered water as far as possible in your fermentation operations. Don’t expose the grains to very hot or very cold water.
Temperature: Typically milk takes around 20 – 24 hours to ferment into kefir at a room temperature of 22–25°C. If this sounds imprecise it reflects the range of factors linked to production. A golden rule is to try and avoid extremes of hot and cold.
Observation: At the outset check the fermentation process regularly, you can’t expect consistency in kefir production unless you control all of the relevant factors. In a normal family kitchen having the oven on or windows open can change the time needed for optimum fermentation. I always check the product (visually) after 12 hours and thereafter at regular intervals.
Avoid: Don’t use of anti-bacterial hand cleaners when working with fermented product.
Manage the grains: Most of the advice says you can handle the grains but your hand should be spotless.
Augmentation: Grain populations increase over time, you will have to remove grains every two weeks or so to keep the fermentation process stable.
Cleanliness again: After every batch make sure that all containers, implements and any gauze or cheesecloth covers are as clean as possible.
Milk and water kefir, resources for anyone thinking of making their own at home.
Kefir resources to help you on the journey of fermentation
Why not make your own kefir, it’s good for you, cost effective and much simpler than you’d imagine. Kefir is really hot right now, it’s got a high visibility in the health and fermented food niche and shows signs that it could break out in the mainstream. I say this as a guy that never heard of kefir a few years ago, now I’m making my own at home. Although making kefir is pretty easy there are a few potential pitfalls, particularly to people new to fermentation, so I decided to share resources that I found useful.
For our own practical guide into home kefir production click here.
Keeping your kefir going, a practical video guide on how to keep the grains living whilst harvesting the product.
There is a BBC guide to the health benefits of kefir, it’s a little bit dated in approach, I guess you wouldn’t expect anything less from the BEEB.
Mad Millie Kefir Kit at Lakeland was our first experience of DIY kefir. The kit contains everything you need to get started and so is a useful first step for beginners. The Lakeland site also has a lot of items that fermenters might find useful including, Kilner jars, cheesecloth, wooden utensils.
A journal study exploring the microbial interactions in kefir, largely linked to the composition and health benefits of lactobacillus.
The Wikepedia kefir page is not the best DIY resource on the internet but it gives a good overview and links to a lot of the relevant research to anyone interested in the science.
The Cultures for Health guide to Kefir, useful information for new and experienced fermenters. Links to plenty of related articles including some water kefir insights.
For information on vegan kefir, visit the Nourished Kitchen website. All the ins and outs of home productions, tips and recipes.
Eat more raw, to get the most from prebiotics and probiotics consider how you prepare your food.
As a fermentation fan and a non-strict vegan, eggs are not normally part of my diet. However a recent scientific study that came out of China got me thinking more generally about food preparation. In the UK eggs have enjoyed a love-hate relationship with food experts and nutritionists. In 1988 Health Minister Edwina Currie announced that UK egg production was badly affected by salmonella. Although she lost her job, uncertainty over the benefit of eating eggs remained. There has also been a long standing disquiet over the suffering experienced by hens in the ‘industrialised’ production of eggs. Scientists still suggest that there may be a correlation between egg consumption and a number of health problems.
Conversely a new large scale study from China has suggested eggs may actually reduce risk of stroke and heart disease. The current advice from the NHS is that the cholesterol found in eggs is less of a health problem than the effect of saturated fat from the cooking process. Indicating that boiled or poached eggs may be significantly better for you than fried. This is not an endorsement of eggs as a health food per se’ but it draws attention to the strong relationship between health and food preparation. So what has this got to do with fermentation, prebiotics and probiotics?
One of the reasons we cook food for a sustained period is to destroy potentially harmful bacteria. It follows then that if food, such as sauerkraut is cooked at a high temperature for a sustained period much of the helpful bacteria will be removed. People starting to think about gut-bacteria from scratch (like us), might be surprised to know that commercially available products thought to be ‘probiotic’ may in fact be pasturised (heat treated) or made from pasturised ingredients.
This is one of the reasons why home fermentation is taking off in such a big way. There are certain challenges to delivering high quality, probiotically rich foods, safely and at a competitive price. So if you are purchasing probiotics check the labels to ensure things are as they appear, in particular watch out for the word ‘pasturised’. This is not so say that you can’t cook ‘live’ yogurt in a curry or sauerkraut in a pork casserole. It’s just you may be loosing a lot of the bacterial benefit.
A quick word about prebiotics. Prebiotic is a blanket term for any food ingredients likely to enhance the growth and development of beneficial bacteria, typically (but not limited to) those found in the large intestine. In order to arrive at the large intestine, food needs to be structurally able to resist breakdown in the stomach. Foodstuffs in this group can (loosely) be thought of as ‘dietary fiber’. If you do a little research in this area you’ll find that many of the most useful prebiotics are in fact raw vegetables. That is because cooking can limit the probiotic benefit effect of certain foods.
There are many valid reasons why people may wish to cook fresh fruit, vegetables and dairy products. The take home point is that if you don’t already, you might wish to take a look at how you prepare your food and the extent to which you are maximizing your support for beneficial gut microorganisms.
We review our first DIY kit on this page, visit these pages for more general information about kefir or links to useful kefir resources
The Mad Millie Kefir Kit from Lakeland was our first experience of DIY kefir. The kit cost £9.99 (at the time of writing) contains everything you need to get started and is a useful first step for beginners.
1 litre glass jar
Stainless steel mixing ball
2 sachets of kefir culture.
On the plus side, instructions are good but simple, the kit contains live cultures that can be used with milk, soy, coconut milk or juice. Everything is pretty good quality and we are still using the equipment even after moving onto kefir grains. The bonus of buying in store at Lakeland is that there’s nearly always someone who can offer some advice or tips. The website also offers a few kefir recipes.
However the cultures can only be reused a couple of times, replacements cultures cost (at the time of writing) £4.99 and produce, this makes the cost of the kefir £1 per litre, not including the cost of the milk or juice. Consider that kefir grains (live cultures) can be purchased for around £5 and have an almost indefinite life.
At the time of writing this product had a 3.5 rating (9 reviews) on the Lakeland website, the replacement cultures were rated as 5/5 (3 reviews). From a beginners perspective this felt like a good purchase, it definitely got us started. The sachets of culture are flexible and don’t have to be used immediately so can be transported or even wrapped up and used as a gift. This flexibility means you pay a premium for the actual product compared to grains.I think this product comes into it’s own as a starter kit and not something for an experienced fermenter. Could be a neat way to get kids involved in taking responsibility of their own healthy diet.
Can fibre reduce your chances of contracting colon cancer?
I have been a fan of Dr Michael Greger for some considerable time. He excels at explaining important and often complex nutrition research in a way that most people can understand. Michael recently wrote about the benefits of fibre to health, its crucial role in feeding the ‘good’ gut bacteria. Put simply out gut bacteria converts fibre into short-chain fatty acids (SCFA). SCFAs deliver a range of benefits and are thought to reduce the chances of contracting colon cancer.
It’s not simply that SCFA promote gut health generally, fibre helps to maintain gut flora. A failure to eat enough fibre can lead to the starvation and decline of healthy bacteria. This typically allows for an imbalance (dysbiosis), where potentially harmful bacteria begin to dominate, perhaps leading to a range of inflammatory diseases and even colon cancer. Further links even suggest a connection to cardiovascular disease, metabolic syndrome and type 2 diabetes.
A relative small amounts of fibre is needed to sustain healthy gut bacteria, in many cases just a handful of chickpeas every day. And yet there is evidence that many people in the USA and UK are failing to include sufficient fibre into their daily diet.