Friday, September 23, 2011

Optimism


 French tarragon responds to spring after its winter dormancy

I know spring is nigh because my French tarragon has kicked into gear.

Here are a couple more reasons to be optimistic. The UN has begun advocating policies to support smallholder agriculture as a way to address world hunger. A recent report by the  FAO's (Food and Agriculture Organisation of the United Nations), 'Policymaker's guide to the sustainable intensification of smallholder crop production', talks about a 'new paradigm of agriculture', 'sustainable crop production intensification (SCPI)', described as:
a productive agriculture that conserves and enhances natural resources. It uses an ecosystem approach that draws on nature’s contribution to crop growth – soil organic matter, water flow regulation, pollination and natural predation of pests – and applies appropriate external inputs at the right time, in the right amount. SCPI represents a major shift from the homogeneous model of crop production to knowledge-intensive, often location-specific, farming systems.
Huzzah!

And the UN Environment Program has just released An Ecosystems Services Approach to Water and Food Security. Name says it all really - great stuff.

That's two good reasons to celebrate right there.

Which fetta is betta? 
After much humming and hawing, I finally succumbed to temptation and bought myself a cheese press. My rickety bamboo-steamer-with-large-rock edifice did the job OK on my first few batches of kefir fetta, but the resulting cheese was prone to disintegration once I took it out of the steamer after pressing and placed it in brine.
My old makeshift cheese press:  bamboo steamer with rock

Kefir fetta pressed with bamboo steamer press, brine and kefir whey solution (water 100%, salt 10%, kefir whey  12%). I cut the cheese up into small pieces because the round fell apart upon being put into the brine. 

My new press, the Seesy Cheese Press, is pretty simple to use and simple in construction - if you've got some construction nous you could probably make one at home with parts from the hardware store. Pressing time is reduced, and the fetta holds its form much better. Oh, and it looks more profesh.
Kefir fetta being pressed in my new Seesy Press. No, that's not bird droppings in jar lids in the background, its a soil structural stability test (very technical as you can see).
Round of kefir fetta pressed in the Seesy Press. Bewdiful!

There is not much to Kefir fetta, once you've got your Kefir yoghurt (labneh). I've written about the labneh making in an earlier post. To make the kefir fetta you just wrap the labneh in a clean cheesecloth bandage (I use dressmaking muslin from Spotlight) and then press it. After pressing, take it out and put it in a solution of 100% water, 10% salt, and 12% kefir whey. Kefir whey is the liquid that drains out when you're hanging your labneh. It should keep for up to two weeks in that brine. You can play around the proportions of salt and whey - 10% salt is quite salty. However, too little salt and you might find that the cheese won't keep as long. 

Next on the kefir list is kefir sour cream and kefir cultured butter, recipes courtesy of Dominic Anfiteatro's kefir website. Today I bought a log of Myrtleford salted cultured butter just to see what it tastes like and for eventual comparison purposes. I think I'll finally get to use the beautiful wooden butter churn my partner bought me years ago which even has the two butter paddles for patting the butter into a block. 

I also did some kefir economics recently. Organic fetta costs approx. $3.78/100g from the supermarket/healthfood shop. It costs me $1.40/100g to make organic kefir (from organic, unhomogenised milk). That's a saving of 63% In my kefir multipurposing quest, I've started to use the labneh in cooking in recipes that call for cream or sour cream. It has to be stabilised first, a fairly quick and easy process that requires an egg white and cornflour (or some other thickening flour like potato flour). Here's a simple explanation of how to do it.

Eating from the patches
Water chestnuts - tops browning off
In early August, I pulled the water chestnuts out of the bathtub where they'd been growing happily in pots, with the soil weighed down by small stones. I let the tops brown off and then in late August, harvested the chestnuts. I've actually never cooked with water chestnuts before, but remembering that sang choi bow has water chestnuts led me to one of my favourite recipe sites, Veggie Num Num and a recipe for a vegetarian version.

As regular readers will know, I'm a make-do kind of cook so I ditched the expensive shitake mushrooms. The result was nonethless tasty and the water chestnuts gave the fresh crunchiness that makes this dish pop.

To make the dish a meal, I went out into the garden and grabbed a handful of herbs, including coriander, parsley and watercress, and made some herb pancakes. These are best eaten with sweet chilli sauce. The herb pancakes are too easy, and can be frozen for 'ron. Make a simple dough with water, flour and salt, and let it sit in a warm place for a while. Roll the dough out into a long rectangle and sprinkle with chopped herbs. Roll the dough  up like a Swiss Roll, then chop thin slices of the roll and fry them in peanut oil. If you don't have peanut oil another light oil would do - olive oil won't work.
Vegetarian sang choi bow with herb pancakes
 Apart from potatoes, which always seem to pop up during weeding of the Peninsula patches, I've been harvesting some good looking beetroots. I've invented a tasty beetroot and fetta salad that can incorporate young broad beans when they're in season.
Beetroots from the Peninsula patches

Ingredients:  beetroot, fetta, onion (preferably spanish but you could use white or spring onions if that's what you've got), young broad beans (if in season, if not, you can leave them out), mint. Olive oil, red wine vinegar, salt and pepper. 

Method: Put the beetroots into a dish with some water - there's no need to cover them, just have them sitting in the water - and microwave them for 10-15 mins or until soft. Slice them thinly. Shell your broadies and boil them until just tender but careful not to overcook them - a floury broad bean is a bad thing. To keep them tender, you can pop them in ice cold water. Thinly slice your onions. Chop up your mint roughly. Combine beetroot, broad beans, mint and onions in a salad bowl. Crumble the fetta over the top. Dress with red wine vinegar, olive oil, salt and pepper. 

This year, I haven't bothered harvesting all the jeruslaem artichokes on the Peninsula patches. Instead I've left them in the ground until I need them. Much easier than defrosting and handling frozen ones! I like to eat them raw - sliced thinly and dressed with olive oil, lemon, salt and pepper. Or I put them into risottos, like the one simmering on the stove below, which also incorporates kale from the Peninsula patch.
Jeruslem artichoke, kale and mushroom risotto

 A work colleague told me about Ecocucina, a fabulous blog about cooking with scraps. Sounds dire, but its far from it. The author is a professional chef. How does fennel mousse with sesame seed and linseed grab them gourmet bones of yours?  

Swale loveliness 

On the swale, the pruned tagasastes have turned on a riot of flowers, attracting many many bees.
 Avocado flanked by flowering tagasastes on the west wing of the swale
West wing swale 

And here's the mulberry, mulched with prunings from a tree wormwood.
Spring approaches and there is so much to do. A compost tea application is definitely on the list, as is mulching the garlic and onions, which are going strong.
Garlic on the peninsula patch - jerusalem artichokes to the rear Marie Antoinette

Friday, July 01, 2011

Taming the tamarillos

Aaaaaaaaah . . . I've come up for air after the end of first semester. Doing a fourth-year agricultural science subject, soil management, meant learning basic stats on the fly - an ugly proposition. But dogged determination, and some crazy late nights, got me through and I'm glad I persevered. I understand a heap more about nitrogen and carbon cycling, soil structure and its relationship to tillage practices, soil acidification processes, and the role of organic matter in soils. I'm also closer to being able to interpret soil tests and make recommendations based on them.

Preserving the neighbourly spirit

Tamarillo tree, inner city patch, May 2011.
 
I managed to find time to pick the tamarillos off our tree in the inner city - and my partner made chutney, a LOT of chutney, out of 'em. The process involved boiling them first to split the skins for peeling.
Tamarillos, skin split after boiling
It seems home preserving was in the air, because the day after, there was a knock on our door and I opened it to find a neighbour bearing gifts: preserved olives and lemon butter. The olives he had picked a couple of weeks earlier from the olive tree in our front garden tree, at my invitation, and the lemon butter he'd made with lemons from his backyard tree. Little did he know that lemon butter is my absolute favourite breakfast spread - it was one of the first things I learnt how to make on my own as a child. Of course he got some chutney.
Lemon butter and olives in brine - neighbourly spirit is a fine thing.
Gordon and Gwen Ford's garden

When a friend invited me to accompany her on a visit to this garden in Eltham, on the north eastern fringes of the city, I jumped at the chance. Gordon Ford was a pioneering Australian landscape gardener whose naturalistic bush-like gardens are both monumental and intimate.
Gordon and Gwen Ford's garden, Eltham

His wife Gwen now maintains the garden and is adding her own stamp to it. I loved every nook and cranny of it.
Pond outside Gwen Ford's house, Eltham
Outdoor oven, Gordon and Gwen Ford's garden, Eltham
Bamboo happiness
A nursery worker at Red Cloud Bamboo shows off a stand of (I think) Bambus Oldhamii.

Back in February, I made at trip to speciality nursery Red Cloud Bamboo to pick up a couple of clumping (i.e. non-running) species for the peninsula property. The long term plan is to grow a (very) small grove there - uses would include garden stakes, fencing, and furniture. The shoots of the two species I bought, Ghost bamboo (Dendrocalamus minor amoneous) and Oldhamii (Bambusa oldhamii) are also edible.  Lots of useful info on bamboo silviculture in Australia, including in particular the effect of thinning regimes on shoot and culm production, can be found in this publication by the Australian Centre for International Agricultural Research: Silvicultural management of bamboo in the Philippines and Australia for shoots and timber.

Australia actually has a native bamboo species, Bambusa arnhemica, that grows wild in the top end. A small number of Australian growers produce edible shoots for the restaurant and gourmet market but not of the native variety (see, for example, www.earthcare.com.au/contact.htm).
Bamboo grove at Red Cloud Bamboo.
Bambusa oldhamii in the inner-city patch
More kefir adventures
After mould developed on my first batch of quick-method Kefir-parmesan, I tried another, and this time it seems to have worked. I've produced reasonably tasty hard, parmesan-like cheese, following Dominic Anfiteatro's excellent instructions in the booklet he gives you when you buy kefir off him. Because I wanted to see whether it would work before embarking on the more involved process of making a proper round of hard kefir cheese, I used his quick-and-dirty method, which involves cutting the as-yet-non-matured cheese up into little cubes and setting it out to air dry. This avoids the need to seal the cheese in wax for maturation.
Kefir parmesan maturing on day 1 (total maturation time approximately 7 days)
I think I'll try my hand at Dominic's recipe for Kefir fetta next. Maybe I'm putting off  making a proper round  of hard cheese because I know it will be the start of an obsession akin to my sour-dough craze.

Peninsula goings on
On the peninsula, the main activity over the past month has been pruning the nut trees on the swale, and pruning back the nurse trees around them. The latter has been a big job as the Tagasastes in particular are fast growing and threaten to shade out the nut and avocado trees. But on the upside they produce lots of mulch, which means less wheelbarrowing of mulch in from elsewhere.

My partner and I also brewed up and applied a late (May) batch of aerated compost tea. We brewed up enough for both a foliar spray and soil application. Pest damage to trees so far is minimal - some feeding on leaves but not significant; no sign of overwintering pest mites such as Bryobia (Bryobia rubrioculus), or Coddling moth (Cydia pomonella) cocooning. But I did spot a Painted apple moth (Teia anartoides) on one of the almonds last weekend, which gave me a fright.

In late June I planted out garlic bulbs, sowed some onion seed, and sowed field peas in the beds that grew corn over the summer. Corn is a nitrogen-hungry crop so hopefully the peas will put some nitrogen back into the soil.

Salt pig from Stonehouse gallery, Warrandyte
 At the 'Canvas and Clay' exhibition opening of my partner's talented mum Sue at Stonehouse gallery in Warrandyte (Sue did the canvases), I couldn't resist buying this handmade oversize salt pig for the kitchen in the new house. Here it is with its big maw open, ready for some sweaty cooking hands. Everyone needs a salt pig, honest.

Marie Antoinette

Friday, May 27, 2011

No quibbles with kibble

Microlaena stipoides seeding on peninsula property
On the peninsula, my partner, my dad and I have tried our first larger scale Microlaena stipoides (Weeping grass) seeding. I've been collecting seed from the indigenous variety that exists on the property. This year, with all the rain and mild weather, the existing Microlaena has really taken off and is now abundant in parts of the property. It's been seeding variably so I've been able to harvest regularly.

We chose a strip adjacent to the back of the dam and ripped planting lines in it at a shallow depth, using a (single-tine) ripper attached to the back of the trusty small tractor. We made two passes for each planting line to try to open the furrow up. Then my partner and I went over the 4 lines manually with picks to open it up more. Then we just dropped the seed in by hand, very thickly, and covered it with a very light layer of mulch (chip from local native trees). We sowed it thick because I want to try to avoid using herbicide, and because my existing seed-production patch, which has been successful, was sown thickly.

Microlaena stipoides seeds sown in a furrow, peninsula property

There are 3 varieties in the lines: the indigenous variety collected on the property; Griffin, harvested from a patch I established using seed purchased from Australian Native Seeds; and Ovens, purchased from Aust. Native Seeds this year.

Nibbling on kibble



Using my new National hand mill to produce wheat kibble
 
Continuing a tradition of giving me archaic presents that may or may not be useful, but are always beautiful, my partner bought me this hand-operated grinder. We tried it on some wheat and it produced beautiful cracked wheat on the first pass. Eventually after 3 passes, we got some coarse flour but that was a fairly slow and tedious process. Methinks the cracked wheat is the go - I incorporated it into a wholemeal sourdough and it adds some great texture.

Kibble is the name given to cracked grains, hence 'kibbled bread'. Burghul, for example, which is the main ingredient in tabbouleh, is cracked wheat. Typically, the kibble is soaked for a few hours before being incorporated into a recipe. You can kibble rye, spelt, buckwheat etc.


Kefir goodness continues
My love affair with Kefir continues. I'm now making kefir-style cottage cheese following the instructions on Dominic's Anfiteatro's site. Its very easy and delicious and has a very similar taste and texture to normal cottage cheese. I add little salt to it as the finishing touch.

Kefir-style cottage cheese draining in my sink

Recently I visited La Latteria, a new cheesery in inner-city Melbourne, and apart from walking away with homemade cheeses and whole (unhomogenised) locally (Craigeburn) produced milk, I chatted to the lady behind the counter, who helps to make the cheeses sold in the shop. I asked her about how she makes ricotta, and it turns out that the process is kind of the inverse of the kefir method. At La Latteria, they heat the whey and add milk until it curds begin to form. With kefir-style cottage cheese, you heat the milk and slowly add very ripe milk kefir until it curdles. Although a brief spot of internetting reveals that there are 101 ways to make ricotta.

She also explained to me why whole (unhomogenised) milk converts more efficiently to cottage cheese than homogenised milk, and produces a creamier cheese. I think I need to get myself this book on the microbiology of dairy - so many more questions would be answered! This accords with my experiences with kefir cottage cheese: if I use homogenised milk I end up with only a small amount of cottage cheese, and whole lot of milky whey and clear whey. When I use unhomogenised milk, I get a lot more cheese for the same amount of milk.

I love the whole ethos of La Latteria. I bought my whole milk in a large glass bottle, which is returnable and gives you a discount on your refill. Nice.


Inner-city patching
In preparation for the move to the peninusla, I've been slowly decomissioning the inner-city patches, which will become a low-maintenance native garden. We're going to keep one garden bed for perennial herbs. I've started the plantings for the native garden with some Myoporum parvifolium (creeping boobialla) from the fantabulous St Kilda Indigenous Nursery Cooperative which has just had a big sale.

 Japanese eggplants from the inner-city patch

The beans turned on a big end-of-season harvest, as did the Japanese eggplants (Solanum melongena, var. Ichiban). Dad pickled some of these using a Claudia Roden recipe from her Book of Middle Eastern Food.  It only took a week for them to mature, and they were so yummy. And I took my first step into pickling, doing a salt pickle of the lebanese cucumber harvest using this recipe from the website of the author of Wild Fermentation, a much referenced book on the topic. The only mildly difficult thing about the process was working out how to weigh the cucumbers down so that they were all fully submerged in the brine. The pickles were delish, especially eaten atop some Kefir labneh on sourdough.


Pickled cucumbers on kefir labneh, atop sourdough

In the city, I've been propagating some plants from seed collected on the Peninsula property, to plant out on the back of the dam there. Success with Acacia vertcillata (Prickly Moses), but no luck with Dianella tasmanica or Indigofera australis, despite following the dormancy-breaking seed treatments recommended by Murray Ralph. After failing to raise the Dianella from seed, I tried just dividing some of the clumps growing near the creekline on the Peninsula and that seems to have worked.

Acacia verticillata seedlings, propagated from seed collected on the Peninsula property

And finally, because there aren't enough rapping scientists in the world, because I'm partial to a spot of David Williamson baiting, and because how can you resist the line "The greenhouse effect is just a theory, sucker. Yeah, so is gravity, float away, motherfucker", check this most wondrous clip out:

Saturday, January 29, 2011

Vampires begone

Braided garlic grown on the Peninsula patch. My partner made two of these braids with help from this handy video. That'll keep those pesky bloodsucking gothic types away from our place this year.

A hazel with Tagasaste and Acacia melanoxylon prunings at the base

Apart from garlic harvesting, there has been work to do on the swale. I've been pruning the nurse trees (Tagasastes, Acacia melanoxylon) that are planted around the nut (almond, hazel, and pecan) and avocado trees. The pruning is mainly to let more sunlight in, especially important for sun lovers like pecans and avocados, and it also provides mulch to keep the weeds away from the bases of the trees and adds organic matter to the soil.

It's interesting to see the difference in form and growth stage of the Tagasastes that have been browsed by wallabies. They are bushier and more compact. And, and unlike the un-browsed Tagasastes, they haven't seeded. This means that their feed value is higher: because they've been kept in the the vegetative phase, the leaf matter is more palatable and nutritious. The ratio of leaf to woody material is also higher. For more information on management of Tagasaste for grazing purposes see this farmnote by WA Dept of Ag


All aboard the trailer train.

Moving mulch with wheelbarrows is not fun - its just not. And we've been doing a lot of it lately, trying to keep the indigenous plantings on the back of the dam weed free. So my partner built this ingenious trailer train. I'm so happy, I'm humming a little trailer train song . . .
Flavours from the patches

Artichokes on the Peninsula patch
Oh the joys of summer produce from the patches - so many flavours and so many possibilities. I follow a loose rule of 'making do' - with what is coming out of the ground, and what's in my pantry and in fridge - substitution is the key.

Artichoke hearts and sorrel and gruyere tart

My father prepared these artichoke hearts following a recipe from my aunt, who learnt it while travelling overseas in Italy. The sorrel in the tart is from the Peninsula patch and the tart is a lovely rich treat. Here's the recipe. Don't skimp on the cream and gruyere.

101 (minus 95) ways with Pesto

Basil harvest always leads to pesto. This batch includes parsley, coriander, garlic and lemons from the patches, with walnuts from a Healsville farmer's market. Pesto is so easy and so forgiving. In its most basic form its just blended basil, pine nuts, garlic, olive oil, garlic, salt and pepper, and lemon. But you can substitute and add ad infinitum. When I don't have enough basil, I use parsley, chervil, watercress, coriander and have even used (lightly steamed) warrigal greens. Any nuts will do. I made a great pesto with salted cashews once. And any strong hard cheese will substitute for parmesan, including tasty, provolone, and pecorino.

Pesto gives a tangy kick to so many dishes. Here are a few of my favourite non-standard uses:
  • add a couple of spoons to zuchini soup at the last minute, or for that matter pretty much any vegetable soup
  • on pizza (smear it over the base instead of brushing with oil)
  • smear it on lamb chops or steak
  • add it to salad dressing
  • add it to bolognese sauce - this is kind of like adding sweet chilli sauce - it lifts the bolognese out of the nursery food doldrums


Zucchini and potato soup is excellent with a few dollops of pesto added at the last minute.


Harvest from the inner-city patch

The staff of life
Sourdough loaf - made according to Dan Lepard's recipe for Mill Loaf (white, wholemeal, and rye flour).

Since buying Dan Lepard's gorgeous book, The Handmade Loaf, I've been experimenting with bread again.

This is expensive flour, but it is stoneground, biodynamic, and from Victoria - that's pretty good credentials.

Olive and walnut sourdough (white, rye and wholemeal flour)
More inspiration has come from this lovely blog on fermentation. I love the commitment to low-tech, low energy techniques - no thermometers or special kits or other fancy equipment. Instead an understanding of the principles of fermentation is used to refine the techniques, particularly the timing.

And I can't resist posting this photo of my Greek neighbour Elsie's amazing Christmas pastries. How beautiful are these?

Wednesday, January 19, 2011

Adventures with kefir

Kefir-leban (or Kefir labneh)

Back in 2006 while on a permaculture design course in Gippsland, I visited the biodynamic dairy farm of Ron and Bev Smith at Fish Creek. The class was offered a taste of kefir milk and I've never forgotten the taste. Finally this summer I got round to buying kefir grains from Australia's own kefir guru, Dominic Anfiteatro.

Kefir starter culture - although described as kefir grains, I reckon it looks more like stringy cottage cheese or little cauliflower florets.

Dominic mails out the kefir culture in a small sealed plastic package with milk. The first step is to strain it and put it in fresh milk in a ratio of about 1:7 (kefir:milk) by volume. The lid must be left slightly ajar as the fermentation process produces carbon dioxide.
Kefir culturing in milk at room temperature.

After 24 hours culturing at room temperature, you strain out the kefir culture and drink the cultured milk. Even though I like the milk, I'm most excited about kefir yoghurt, which Dominc calls kefir-leban, after the middle eastern labneh. So I hung the cultured milk in a piece of cloth (I cut up an old sheet) for 24 hours to drain. And lo and behold, I had labneh.

Its hard to describe the taste of kefir labneh - it is 'peakier' than normal yoghurt or labneh, but that is offset by a unique freshness and texture. Labneh can be made by hanging normal yoghurt as well - I like this stuff better.

One of the most gratifying things about the process is how straightforward it is. You don't need to sterilise equipment, just keep everything reasonably clean, including your hands. This is, in general terms, because the organisms in the starter culture compete so effectively for resources relative to the spoilage organisms.

You can use any type of milk: homogenised and pasteurised, unhomogenised and you can even use low-fat milk or any of the other 'enhanced' milks on the market, although I would recommend you keep it as unprocessed as possible and go for organic and/or biodynamic unhomogenised milk, or if you can get it (lucky you), truly fresh straight from the cow/sheep/goat.

The kefir culture is like sourdough in that it needs to be fed regularly. When you're not culturing a product, you store it in milk in the fridge. If you want to take a break from culturing it, the starter culture apparently lasts in the same milk in the fridge for over a month. As you continue to culture the kefir to make products, it increases in volume, and therefore so does your end product. When you think you have too much for your needs you can store it according to Dom's instructions or give some away to friends.

Like sourdough, kefir culture is a mixture of yeast and bacteria and like sourdough the particular species vary by location. A section on the microbiolog of kefir and lactose digestion is included below.

Kefir labneh with herbs (chives, parsley, tarragon, watercress). If you stir vigorously with a fork, you can make the texture like cream cheese.

I've only just scratched the surface of what can be done with kefir labneh. In addition to the herby cream cheese concotion above, I've also put it in a veggie curry as a thickener, added honey to it for a sweet snack, smeared it on sandwiches and toast instead of butter and, my favourite so far, added homemade horseradish (see June 2009 post) to it and served it on steak. Dominic's site includes recipes for all sorts of goodies, including soft and hard cheeses. Think I might try a soft cheese next.

Homemade horseradish: dig around the roots of your horseradish plant, cut off a piece of root, wash, grate, add vinegar, enjoy.

Much of the non-scientific literature about kefir refers to its reputation as suitable for people who have trouble digesting lactose. I did some research on this and found that the scientific literature is clear that lactose digestion is improved from fermented dairy products in general, such as yoghurt, as compared to milk. While it seems clear that kefir is equally as effective as yoghurt in terms of aiding lactose digestion, the evidence for it being better than yoghurt is probably inconclusive.

A microbiological diversion

For those of you with an interest in the microbiology of kefir and lactose digestion, here is the lowdown. An article on kefir in the Journal of the American Dietetic association describes its composition and fermentation action as follows:

"These grains are mass of bacteria, yeasts, polysaccharides, and other products of bacterial metabolism, together with curds of milk protein . . . . Kefir typically has a larger and more diverse range of microorganisms in its starter culture than does yogurt. For example, the kefir used in this study contains the following cultures: Streptococcus lactis, Lactobacillus plantarum, Streptococcus cremoris, Lactobacillus casei, Streptococcus diacetylactis, Saccharomyces florentinus, and Leuconostoc cremoris. The dual fermentation by the lactic acid bacteria and yeasts in kefir results in the production of small amounts of carbon dioxide, alcohol (0.01 to 0.1 g/100 g using starter cultures), and aromatic molecules that give kefir distinctive organoleptic properties compared with yogurt. Kefir typically has a tart flavor, is slightly carbonated because of the naturally occurring carbon dioxide, and is somewhat thicker than milk." (http://dx.doi.org/10.1053/jada.2003.50111)

Lactose digestion is attributed to the activity of the enzyme p-galactosidase which is present in our intestinal mucosa (interestingly, the level of activity of this enzyme varies with ethnic origin). When there is low mucosal P-galactosidase activity, lactose is poorly digested and reaches the final section of the small intestine (the ileum), where it is fermented by the native bacteria there. The volatile end-products of bacterial fermentation of this undigested lactose (i.e. volatile organic acids, carbon dioxide, methane and hydrogen) cause the symptoms of poor lactose digestion.

Lactose digestion is enhanced if it is consumed together with fermented milk products such as yoghurt. This enhancement is attributed to the presence of β-galactosidase in the starter culture bacteria for yoghurt, particularly the lactobacilli species (lactobacilli are bacteria that convert sugars, including lactose, to lactic acid). Because yogurt has good buffering capacity, it allows some of the bacterial cells to survive the gastric acid in the stomach and reach the first section of the small intestine (the duodenum) intact. At that point, it is thought that bile acids play a role, either by causing the breakdown (lysis) of the bacterial cells, thereby releasing β-galactosidase or by altering of the permeability of the cell membrane so that lactose can easily enter into the cell. Whatever the mechanism, the β-galactosidase gains access to the lactose substrate. Thus yoghurt is said to have an "autodigestive capacity".

Neat eh?

Marie Antoinette