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.
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.