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.
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.
Home fermentation, have you tried the Kilner fermentation set?
Is a home fermentation kit necessary? For the occasional production of sauerkraut I’m not sure that special equipment is essential. Maggie has managed to keep us supplied with our fermented foods simply by using medium sized jam jars, and a range of normal kitchen utensils. The point she always stresses is that everything has to be clean. The fermentation vessel should be thought of as a bacterial incubator. If you incorporate harmful bacteria into the incubator it will inevitably grow quickly. You should throw any tainted product away , clean everything and start again. One of the many appealing aspects of home fermentation is the relatively low cost of fermenting produce. Consider that at current prices a liter of organic sauerkraut can be created for less than 50p (ten bob!).
I know that previous generation of home fermenters from Poland and Germany actually had a range of fermentation pots and tools that were accumulated through the course of married life (I don’t remember seeing any of these is the kitchen of my mother or grandmother). In particular ceramic pots that were dedicated fermentation vessels. They had necks wide enough that a small plate or large saucer could be accommodated within to keep the fermented product under the water level.
With the rising interest in home fermentation equipment has passed from specialist shops and online retailers into mainstream retail outlets. We purchased a Kilner fermentation kit at the weekend. Our primary motivation was to increase the volumes of our product. Not only has our own consumption increased but we are also sharing more with our own friends and family. It certainly seems that the public awareness of the benefits of fermentation is growing. The Kilner kit was fairly priced (£18) when compared to similar products and the fermenting jar was around the size we were looking for (3 liters). It all seems OK, we’ll report back when our first batch is ready (cabbage and carrot). We have no particular connection with Kilner, save that we use their 1liter fermentation jars already.
We’d be really interest in what other home fermenters use, and any equipment related tips would be most welcome. Feel free to leave any suggestions, comments or feedback in the box below.