ROOF TOP VEG PLOT

How to Make Thick and Creamy Yogurt with 100% Raw Milk

This is the raw milk at blood temperature. pic.twitter.com/sjJ6XWKZEZ

— Wendy Shillam (@Rooftopvegplot) May 18, 2016

Above testing for blood temperature 

I’ve started buying fresh, raw milk from the Calf at Foot Dairy in Suffolk. And the first thing I’ve been doing with the milk, apart from drinking it neat straight from a very cold refrigerator*, is to make yogurt.  This required a bit of experimentation. The Internet seemed remarkably silent on the topic of making yogurt from raw milk.  Most of the websites I looked at told me it couldn't be done and others – mainly US sites – warned that famine and plague would come of eating raw milk.**  Undaunted, I transferred my gaze from cookery sites to scientific sites.  Then having understood the science I started experimenting.  And having devised a few good recipes, now is the time to share.

First the science

What is raw milk?

Raw milk, direct from the dairy, is untreated and comes from grass fed cows.  It is neither pasteurised, nor homogenised in the way that mass market milk is.  In addition grass fed cows naturally develop a whole range of good bacteria that grain fed cows do not.  See Fiona Provan’s Calf at Foot Raw Milk Facts  for more information. 

The reason why supermarket milk is habitually treated is that the industrial process of dairy, to supermarket shelf, to kitchen, is fraught with delay and potential for contamination or putrefaction.  It is necessary to sterilise the milk, denuding it of its friendly bacteria, in case some unfriendly bacteria has got in somewhere.  The process also changes the structure of the milk making it white, uniform and boring.  Real raw milk is creamy and delicious.  It’s alive with health giving bacteria, so every batch of yogurt that I make will turn out slightly differently. 

What happens when milk turns into yogurt?

When I add a yogurt starter bacteria to milk it gets to work on the sugars in the milk, turning the lactose into lactase.  This increases the acidity of the milk and causes the mixture to coagulate.  Adding rennet to milk – an acid – achieves the same effect, making junket or cheese curds. Movement has a similar effect whipping cream and eventually forming butter.  This is called denaturisation. The casein protein, in the cream of the milk naturally denatures, i.e. unfurls itself and binds together in the presence of the appropriate bacteria.  However the protein solids in the whey do not naturally change so readily unless the milk has been heat treated.

That is why pasteurised milk makes a thicker yogurt. 

If we heat raw milk we get thick yoghurt, if we don't heat it we get to preserve the rich bacteria that we bought it for in the first place. But the result of a low heat yogurt process  will be runny and sometimes grainy.  The recipes below show how I balance these two contradictory functions to produce delicious, thick and creamy yogurt full of healthy live bacteria. 

Equipment

Life is too short to use cooking thermometers.  In this article I'll teach you how to recognise the key set points.  There is room for error.

I use two wide topped vacuum flasks, made by Thermos and available here.  They hold 0.7 litres each.  They are not as efficient as a coffee flask, so to conserve the heat for a long time, to mature the yogurt, I pre-heat the pots with hot water and then plunge them as soon as they are filled into a home-made haybox.  Mine is an ordinary cardboard box padded with Woolcool, the sustainable packaging my milk delivery comes in. 

Woolcool ready made haybox.

Faisselle containers can be purchased from Fromage Maison or the pots and container can be saved from an imported faisselle cheese. I buy faiselles from La Ferme de Treillebois in Normandy from our wonderful local cheese shop Fromagerie.  (but they don't do postal sales.)

How to make the yogurt

Any yogurt is best made in a warm but spotless kitchen.  This is a slow process.  It is not difficult, but it is one of those processes that seems to work best if not rushed.

Low heat raw milk yogurt

If I have a rich and creamy milk, I can make a small quantity of yogurt by heating 1.4l milk to blood heat. Test with a finger as you would for a baby's bottle or bath.  I call this the Alice in Wonderland Test; neither too hot, nor too cold. 

Add 3 heaped desert spoonfuls of a live organic yogurt (either purchased or saved from the last homemade batch.)  Stir the yogurt in well before decanting the still warm liquid into two wide topped Thermos pots, secure the lids tightly and tuck them directly into a haybox, or a warm airing cupboard for 12/24 hours.  The bacteria will continue to develop, if the yogurt stays at about blood heat.  (37•C, 98•F)

However, it is unlikely that the yogurt will be fully set because you have not denatured the whey proteins with enough heat.  The resulting yogurt will be creamy on top, and a little watery below, more like a yogurt drink than a foodstuff.

Straining the yogurt through a cheesecloth for a couple of hours, will produce a thicker yogurt, but will obviously reduce the quantity.  Straining the yogurt overnight will produce a much drier product that by then will have developed the characteristics of cream cheese.  Don’t be put off by the rich, almost buttery residue that sometimes floats to the top.  This is actually clarified butter and can be folded into the rest of the yoghurt.

Have turned the kitchen into a raw yogurt dairy. This is straining. pic.twitter.com/IIf4l9Owba

— Wendy Shillam (@Rooftopvegplot) May 18, 2016

Above: The fresh yogurt being strained in a cheesecloth

 

Yogurt strained for 12 hours produces a lovely creamy cheese

Another solution is to purchase a faisselle box.  This is a plastic container with four slotted pots within it.  Spoon the yogurt into the pots.  The whey will naturally drain out of the pot, into the container, but will continue to blanket the pot, keep the resulting faisselle cheese or fromage frais in excellent condition.  The little mounds of fresh white cheese can be sweetened, salted or flavoured with herbs to provide a variety of treats. 

Faisselle comes with box and strainers intact - cheaper to re-use than to buy the pots separately.

High Heat Raw Milk Yogurt

One of the pitfalls of a low heat yogurt is the uncertainty of knowing what bacteria might or might not be present in the raw milk.  In this more controlled method I heat the milk to scalding point.  This will kill off a lot of the natural bacteria, but it doesn't damage the proteins and it will fully denature the curds and the whey, forming a set yoghurt. 

Testing the temperature:

Scalded milk is brought gently to the point of boiling, but it is not allowed to boil.  It is pretty easy to see when this stage is reached.  A skin might start to form and crinkle.  Keep stirring to discourage this skin formation.  Steam will start to be rise, a few bubbles might form around the rim of the pan.  If I take a sniff I can smell that sweet, hot milky aroma, reminiscent of bedtime drinks and rice puddings.  It is the smell of lactose as it starts to break down into lactase. 

Heating raises the acidity of the milk, the sugars break down and the curdling process can begin.  As long as I am heating the milk gradually it won't matter if the milk starts to bubble.  I simply turn down the heat and keep stirring. 

Method

Heat 1.4l of raw milk to just below 100•C (212•F)  (as described above)  I try to keep the milk at the scalding stage for two or three minutes.  I want the curding process to be able to begin as soon as I put the starter yogurt into the mix.

Now I let the milk cool slowly to blood heat.  Don’t rush this process, putting the yogurt in too quickly might kill it.  As before once you can stick your finger into the milk and it feels just right mix 3 heaped dessertspoonful’s of starter yogurt into the milk.  Place in two Thermos flasks and plunge straight into the haybox or airing cupboard for 12/24 hours.  The yogurt should still be warm when you remove it from the box. 

You will find that you have a lovely thick yogurt.  If it is not set enough for your tastes, but has cooled down you can re-heat to blood heat and re-seal the Thermos flasks.

The rational for heating

Now the observant among you will recognise that in heating the milk to near boiling, I have effectively pasteurised it.  But there is no cause for despair.  The factory process involves a lot more that heat. Milk can be denuded of its cream to thin it or have dried milk added to it, which thickens it.  The milk can be forced through a spray device, that breaks down the nodules of fat, making them easier to digest and thus more fattening.  And milk destined for yogurt manufacture can, quite legally be adulterated with stabilizers such as alginates (carageenan), gelatins, gums (locust bean, guar), pectins, and corn starch.

My yogurt will only contain milk.  By heating the milk I have created a blank canvas on which to caste my own cocktail of microbes.  I can use some of the yogurt from the low heat batch, which will contain replicas of the raw milk microbiology that I've just 'killed off".   The important thing to remember is that this higher level of heat has changed the state of the milk, meaning that we don't have to rely quite so much on atmospheric souring as the low heat yogurt does. 

Keeping

Keeping any yogurt or cheese in the fridge will stop it maturing, but will not kill the microbes.  Keeping the produce in the larder will maintain the process and gradually change the flavours. 

If it tastes funny, don't eat it.  If it tastes and looks fine, it probably is!

Read the blog. How to make yogurt from raw milk. https://t.co/M84RuLVsw3 pic.twitter.com/bhX8nNQErW

— Wendy Shillam (@Rooftopvegplot) May 19, 2016

 Above: High heat raw milk yogurt.

* I keep most foodstuffs in a cool larder these days. So my tiny fridge is reserved for things that really need cooling.  Fresh milk and yogurt are two of these perishable items, being kept in peak condition at a temperature of 2°C (36°F)

** Fortunately my canning research has taught me that some people in the USA are terrified of the real.  I think that is partly because American food is generally so industrialised, adulterated, diluted and generally messed about with.  For example, in America they wash their fresh eggs in something nasty, and in so doing remove the delicate shell coating that naturally protects an egg from tainting!  So, American housewives can no longer keep their eggs in the larder, as we do.  They have to seal and refrigerate them – ugh!

Demystifying Pruning; Grapevine

vitilab.com

I've was watching a video on viticulture the other day when the TV picture jarred to a still and the presenter said, "Let's just watch that again." We went through an action replay of the vineyard owner showing us what a fruiting spur looks like. The presenter said, "Look how Harry is so quick on the draw." It still took a couple of run-throughs and a big red arrow on the screen for me to spot that while he was talking to us, Harry had whipped a pair of secateurs from his pocket and snipped off a shoot. 

It was a Damascene moment.  The shades were lifted from my eyes.  Suddenly I realised that pruning is not about cutting off limbs, or prettification. Pruning a grapevine is about increasing quality, creating form and vigour. It is often about decreasing, rather than maximising yield, in order to increase quality.  Viticulture is a year round process of tending, not an annual assault.

Three years ago this week I snipped three tiny shoots from a grapevine in France.  Now, three years later, my own grapevine, grown from one of those cuttings, is flowering for the first time.  I'm going to share with you a few of the things that finally fit into place for me, thanks to Quickdraw Harry. 

Phases of Plant Growth
When you start off a cutting or bring home your young vine from the nursery the books on pruning seem extremely confusing.  That is because regular annual pruning is reserved for mature vines.  What you have is a juvenile and there's a lot of different work to be done before that callow youth will be allowed blossom. 

Trunk
In the first year or two you will need to concentrate on forming the trunk of the vine.  This is the bit that will support the growth and grow thick and strong.  But now it's unlikely to be thicker than a pencil stem, so it can be trained, bent, curled around a pillar or trimmed to the desired height.

Laterals
As the stem grows it will naturally start to sprout side shoots.  You will need to decide how many of these side shoots or laterals you wish to keep.  The fewer you preserve, the stronger the vine.  Some pruning methods keep hardly any laterals, preferring to get the grape to grow new ones every year.  In other forms, and recommended for an ornamental pergola, it is better to plan to mature few laterals.  Then each year the pruning will be easier. 

Bending the main stem
The main stem can also be persuaded to act like a lateral once it has reached the top of the trellis or support.  It will naturally bend over and can be trained sideways.  Similarly you can encourage twin or four stemmed lateral growth, which will give you a bit of insurance in case one of the stems becomes damaged. 

Fruiting Spurs
These are the final stage of training.  The fruiting spurs are formed naturally as a consequence of bending the stems horizontal.  The sap rises to the top of the twig, which encourage the formation side shoots.  (The same things happen when you train a climbing or rambling rose.).  Each of these fruiting spurs will eventually support the fresh shoots on which the grapes will form. 

So you now only really have three terms to get to grips with;

• Trunk
• Laterals
• Spurs

All grapevines, however they are trained, will possess these elements to a greater or lesser degree.  But there are more pruning forms than three leaf clovers.  Some forms have very short trunks keeping the bush close to the ground, where it can benefit from reflected heat from a light soil.  Some people cut the laterals right back every year, so the horizontal wood is regularly renewed.  Some train the spurs skywards in single or double rows of wires like telegraphy wires.  In some forms the fruiting spurs hang downwards.   

Choosing a shape
Now that you understand the three parts of the grapevine, you can start to think about its final form. Look at the sketches below for just a few options.

fruit.cornell.edu

In the garden there are even more. You can fan train a grapevine against a wall, or on top of a tall stem you can form a criss-cross of laterals to cover a pergola. 

houseplantsguru.com

Even in a pot you can bend the young stem around in every decreasing spirals outlining a Christmas tree shape.  Remember the need to keep the laterals more horizontal than vertical to encourage sprouting. 

The final form will depend on your taste and on the natural growth of the plant.  If the stem bifurcates, as happened with my vine, then go with it.

Forming the framework
Once you have decided on the form, the first few years will be concerned with ensuring that the structure is sound. Remember that the main stem will grow thicker every year, so make sure it is well staked and that the ties are not too tight. Choose laterals carefully.  These tend to be gangly in their first few years.  If they grow too wippy, trim them back by a third or a half, to strengthen the framework.  The laterals can always be extended next year from a new end spur or trimmed right back to let another one form. 

Forming the spurs
In the books the gradual progression of tending a young grape through the formation of stem, laterals and spurs is generally equated to three years growth. This is an over simplification. For a start the stem may only really get going in the second year of growth and the transition between stem and lateral is often gradual. However, the formation of spurs definitely mark the the end of the juvenile stage. To form the spurs you will need to be aware of one great truth about viticulture:

THE FLOWERS ONLY FORM ON THIS YEARS GROWTH

No amount of tending, snipping, training or bending will encourage the hard wood of trunk or a mature lateral to shoot, let alone fruit.  Hard wood only shoots where it is pruned.  The aim is to help the hardwood of stem and laterals to become strong.  The lateral, which must always be horizontal or at least angled more than 45• away from the vertical, will form spurs only when it is young.  The books talk about stems no thicker than a pencil.  That is a useful rule of thumb.  Once thicker than this, new spurs will be less likely to develop. 

So early on in the life of the lateral we must choose shoots that will form the spurs of future years. 

These spurs form naturally from a young horizontal lateral and can be trained upwards, sideways or left to hang down. 

I've just pruned my vine to form a spur shoot at approximately 250cm intervals (a handspan) along the lateral, trimming away any growth between these points.  This is what many books refer to as the third year of training and for me it has come on the third anniversary of my taking cuttings.  This is also the first time I have seen flowers on the vine, some of which have been pruned away in the process of selecting spurs.

Spur formation on my three year old vine

It's all about quality

Don't worry if you are cutting away vigorous shoots. Pruning is about conserving the vigour, so that energy is diverted to the fruit and not the bough.

Over time the spurs that I have selected will be pruned back every year. Eventually they will become hardwood nodules, creating that lovely gnarled effect that we see in an old vineyard.

Once the form is established pruning systems change.  Regular pruning is done in autumn and /or in late spring, once the threat of frosts is past.  Every year each spur will then be encouraged to form a series of new young shoots.  Choose two to remain and trim the rest right back.  With luck each spur will form two vertical stems and two bunches of grapes on each stem. 

But the tending process goes on right through the growing season.  In the UK we are advised to cut back any further bunches beyond two per shoot, to cut away leaves that overshadow the grapes and halve the number of fruit on the bunch to ensure full ripening.  Similarly at any time in the season a spur might run to wood, creating a long non fruiting arm.  That is best cut right back.

This is why I like to use the term 'tending' a grapevine rather than pruning.  Tending implies the regular and gentle maintenance that a viticulturist naturally employs.  In the video I was watching Harry the winegrower had snipped away at an extraneous shoot from the side of a spur.   It wasn't the right time of year to prune.  Perhaps he'd noticed some damage.   But he'd seen the problem and - snip - he'd dealt with it. 

In the autumn, once the fruit has been picked, all of that year’s growth will be cut right back to the hard core of the plant.  Fruits will not be born on that wood next year. In winter well trained vines look like soldiers in the vineyard, so regular and rigorous is the regime. 

In a home trellis I don't need to be quite so regimented.  But the basics of pruning for yield and quality can be seen all across the rooftopvegplot plot.  The Japanese wine berry has its old shoots trimmed right away and the young shoots cut back to reduce the wood and ensure that I have fresh young canes to bear fruit. 

The fan trained elder, which is doing splendidly, has short spurs from each lateral, and on each one, just like the grapevine, the succulent florets of elderflower are already in bud. The tall, sterile shoots will be trimmed off, unless I wish to preserve one to form another lateral of the fan, bending it down to encourage fruiting spurs along its length. 

Even the wisteria will be cut hard back, reducing the wippy shoots that form only leaves, in favour of short vigorous shoots from spurs that form the flowers.