The Taleggio Experiment

The decision to rent the School of Artisan Food was made, a recipe was researched, whilst attending a course there, I was able to work out what equipment we’d need and finally our dates rolled around.  Rose purchased containers, filled them with milk and sent them off with a refrigerated courier.  I drove myself off to the School of Artisan Food and got ready to receive milk.
I spent a day sanitising equipment and writing up a HACCP plan for our trial production and the following day was in bright and early for the milk to arrive.
Taleggio is an interesting make from my point of view, in that it uses thermophilic bacteria as a starter culture and yet doesn’t use the temperatures at which thermophilic bacteria tend to work best.  Like all washed rinds, the curd doesn’t want to acidify very much and it wants to retain a calcium rich, pliant structure.  The thermophilic bacteria therefore are used precisely because they will start working but as the temperature of the make cools off when the cheeses are in their moulds, they will stop going, the acidity will level out and won’t develop further.  This in theory and coupled with curd washing, should mean that the cheeses remain pliant with their moisture locked within the curd structure and soften when ripe to a gloriously oozing texture.  That is the theory anyway.
Taleggio photo courtesy of the
Within this, of course, there are many parameters to play with.  So many, in fact, that I wish we were in full production right now in some ways so I could be happily making cheese day after day, tinkering with a whole multitude of variables.  Would a degree or 2 more or less in terms of temperature affect the rennet set and the texture as the cheese matures?  How would the flavour and acidity be affected if I remove a bit less whey at curd washing?  What if I add in more starter cultures at stirring?  What if I stir for longer?  That’s not even getting started on how much starter we need to use to work with our milk and how much rennet will get me a 15 minute flocculation and 45 minute hardening time (which, I believe, is what I’m aiming for).
First challenge and challenge not yet overcome at that, is the quantity of starter.  There are no hard and fast rules for this of course because the amount of starter you use is entirely related to the numbers of lactic acid bacteria in your milk.  Thinking back to my Holker Farm days and remembering the drainage battles we had balancing acidity and calcium, I figured that if I wanted to have a slow acid development, even though I was using thermophilic bacteria this time rather than mesophilic ones, I should be using pretty small quantities of starter.  In retrospect, I’m not sure that was the case, but you live and learn.  I remembered that when I left Holker, we were using tiny quantities of bulk starter, having been advised to drop to around 0.025% and before that had been using still pretty tiny quantities at 0.05%.  I decided to start at the higher of these values, having made up a yoghurt culture in skimmed milk the night before and incubated it overnight.  Yoghurt cultures, for those who didn’t realise, are thermophilic bacteria.
Now, at this stage, the benefit of recording values of acidity began to hit home.  In all my time at Holker, we never recorded a pH.  The pH meter had broken before I arrived and they are very expensive bits of kit to replace.  We took titratable acidity of course but the TA of our starter cultures which I took every so often, are hard to correlate with that of this yoghurt because of the buffering factor.  Our starters at Holker were made up in sheeps milk, which is high in protein – it can be up to 3 times that of cows milk.  My yoghurt cultures were made up in UHT skimmed cows milk.  As you all no doubt remember from the pH and Titratable acidity post last autumn, protein captures Hydroxl ions (OH-) when you add the alkaline solution looking for a pink colour produced by its reaction with the indicator, phenolphthalein.  This distorts the correlation between acid and pH because it is non-uniform.  The more protein the milk has, the more Hydroxyl ions it can capture and the more Sodium Hydroxide needs to be added before a reaction with the indicator will register.  In other words the TA value will be higher in sheeps milk than in cows milk just down to the protein.  In fact, at Holker when we began making cows milk and sheeps milk cheese side by side, we noticed a huge difference when recording the TA at 24hours (or thereabouts) between the two.  Our sheeps milk St James regularly recorded 80-90 ’D while the cows milk Brother Davids struggled to reach 40’D.  You would think that the majority of the protein in the sheeps milk had been locked up in the curd by then but just as the milk is higher in protein, so is the whey and so the titratable acidities ended up being quite dramatically different.
Anyway, returning to the matter in hand and hope I didn’t lose too many non techno cheese geeks along the way.  There was no point, to my mind, trying to correlate vaguely remembered TA values of starter culture with a yoghurt I had just made as I didn’t have any of those values recorded for reference.  So I took a pH reading of the starter and was conscious it was more acidic than my notes from Ivan Larcher’s course suggested was ideal (pH 5 – to make sure you catch the bacteria while they are multiplying happily and before the lactic acid they have produced can denature them and kill them off), but otherwise didn’t have much to relate it to.
On the first trial, 0.05% in quantity was added to 50 litres milk, the milk was heated to 34’C, rennet added at the appropriate pH change and I filled my pot of water to look out for flocculation times.  The flocculation happened right on time, the hardening more or less followed the pattern it was supposed to.  I pre-cut, then cut to hazelnut size (more or less – it’s a bit hard to use a cutting harp designed for a big vat in a 50 litre tub), let if settle, took off the 25% whey, added back the appropriate quantity of water at 32C, added some starter back in for flavour and stirred.  The recipe was one I’d found online and frankly has already been adapted.  At the time, I queried curd washing with Ivan Larcher and he replied
‘Good luck settling the pH at 5.2 without it.’
Later on, I asked for clarification on quantities and adjusting those parameters only to be told that it’s an industrial technique and he didn’t recommend me doing it.  I have therefore stopped.
However I was doing so on this trial make, and at every stage, I was recording pH on the spreadsheet Ivan had emailed me after our Blue Cheese course so that it would track the pH curve.  Unfortunately my pH curve didn’t curve.  It was more of a wobbly straight line.   Short of leaving the whole thing for 24 hours to acidify on its own, there wasn’t much I could do but proceed, pre-draining the curd on a mat and then filling the moulds with the drained curd pieces and turning, turning, turning throughout the afternoon.
All looking quite convincing so far – unfortunately it’s all in the maturation.
They looked pretty convincingly like cheeses.  They were draining.  But who knows what was going on below the surface without much acidification.  The problem is, all sorts of other bacteria could be enjoying the quantities of lactose and developing to undesirable results.  Unfortunately despite doubling the starter cultures the following day, the same acidification pattern followed.  Evidently at Holker Farm the starter culture had very minimal effect and acidification was largely governed by the lactic acid bacteria naturally present in the sheep and cows milk.  Further unfortunately, I already knew from a lactofermentation we had done a week or so earlier when Rose drove up (bringing a bottle of milk with her) to SAF to meet Ivan and me after one of the days of the course had finished, that we didn’t have a lot of strong lactic acid bacteria in our milk at the moment and that other things tended to become dominant.  To say I was nervous of the test results we would get from milk and curd samples would be an understatement.
I left SAF; the samples headed to the lab; we waited for the results.  As I had feared, without enough lactic acid bacteria from the starter or naturally present in the milk itself, enteros and pseudomonas had had a field day.  Staph. aureus hadn’t done so badly either.
Not quite what I was hoping for but still looking relatively like cheeses
After a couple of weeks, I drove to SAF to collect the unfortunate cheeses.  I did not have high hopes to be honest, particularly as one of them had pancaked overnight and collapsed – a bit of a surprise for me and also for Lee Anna.
However, I had known, that I had more cheese than I was expecting, which I suspected meant they were too moist.  This raises the likelihood of crazy things happening during maturation.  What I didn’t know however until I began to think and mull it over was that those rather too healthy pseudomonas might also have played a part in this too.  Pseudomonas, as I had discovered thanks to the very knowledgeable Paul Thomas, are caseolytic (they eat casein).  Could that mean that they might increase the speed and amount of protein breakdown in our cheeses?  One quick email and a reply later and yes, by no means the only factor but, if there were large numbers of pseudomonas, then there was much more chance of pancaked gooey cheeses that fall apart.
All in all, I wasn’t sure what I would find at SAF but although one batch had fallen to pieces, the other did seem to be holding some shape and smelled convincingly washed rind.  Not the best behaved of washed rind, I’ll admit, but I’ve smelled worse in my time.  We tasted one of them and to my surprise there wasn’t a strongly bitter flavour that I was expecting due to the pseudomonas, in fact the predominant flavours were beery, yeasty and fruity with a hint of meaty and savoury in the background and perhaps just a touch of the bitterness on the rind but certainly not overpowering.
Now let’s be clear, it’s not the flavour profile I want but then again, the recipe didn’t work, so for it to have turned out to be not only edible but while a bit raucous, actually not too bad, was a definite bonus.  That said, a valuable lesson was learned for Cheese Trial no 2: use a hell of a lot more starter!

Acidity and Cheesey Chemistry

Before any of my long standing friends wonder who I am and what I’ve done with Anne, I should point out that the chemical knowledge in this post is courtesy of the collective brains of Dr Jemima Cordle, Dr Katie Jewell and M. Ivan Larcher who have very kindly either taught me the info or have answered my questions on the subject.  I hope I have interpreted it correctly.  Any chemists out there, please pick me up on any mistakes so I can correct them.

The difference between titration and pH is that you use titration to calculate the concentration of Hydrogen ions by means of measuring the amount of alkali ions you have added to cause a certain colour change.
A pH measurement is the log (base10) of the concentration of Hydrogen ions.
pH meter at Neal’s Yard Creamery recording acidity development of Finn curd
Titratable Acidity kit set up at Old Hall Farm
Hydrogen Ions, Hydroxyl Ions and Acidity
In a basic solution there will be Hydrogen ions (H+) and Hydroxyl ions (OH-).  The H+ ions determine the acidity of a solution and the OH- ones are in predominance in a basic solution (when you stick both ions together you get H2O which is water)
Although pure water is present largely in its molecular form rather than atomic (which means that there are bonds linking the H atoms to the O atom to form the water molecule) a portion of it is ionised and present as H+ and OH-.
Because these two ions are present in equal quantities in a pure solution of water it remains neutral with a pH of 7. (The actual pH number is derived from the concentration of H+ present). 
When substances are dissolved in water they often disturb the H+ OH- balance. 
When the concentration of H+ is higher than the concentration of OH- the solution is said to be acidic and the pH is less than 7. 
When the concentration of H+ is less than the concentration of OH- the solution is said to be basic and the pH is more than 7. 
Acids and bases can vary hugely in strength. Hydrochloric acid for instance has a lot of H+ ions present and has a pH of 1. Citric acid on the other hand has less H+ ions present in it and has a pH of around 2.5. 
How the pH meter measures
A pH meter is able to directly measure the concentration of H+ ions present in a solution into which the probe is stuck. It then converts this concentration to the pH reading. 
How the TA measures
Titratable acidity measurement on the other hand is an indirect technique to measure the H+ concentration. There are certain ‘indicator’ solutions available that change colour when the solution they are in gets to a certain pH.
In cheesemaking we use phenolphthalein which turns pink when the solution gets to pH8.3. So we add a basic solution (NaOH or sodium hydroxide) to the milk or whey until enough OH- have been added to cause the colour change.
The amount that has been needed will tell you how many H+ ions were present in the original solution.
To milk you need to add very little NaOH because milk contains a very small amount of H+ but to whey from cheese the morning after making, you need to add a lot more NaOH because the lactic acid bacteria have produced a lot of acid and therefore a lot of H+ ions are present.
Having said this there is a complication which means that the pH/titratable acidity measurements are not 100% correlated. The complication is an interesting acid/base phenomenon known as buffering.
Buffering happens when an acid or base is added to a solution, but the pH does not change. This happens in cheesemaking because there is a lot of protein present.
The protein is able to capture H+ ions as they are formed and therefore prevents them from ‘being seen’ in the solution. They do not add to the H+ concentration that determines the acidity.
This can also happen with OH- ions – the protein can capture them and stop them from causing a pH change.  
The latter is relevant during titratable acidity measurements because sometimes even though OH- ions are being added they are not being used to neutralise the H+ present and raise the pH to 8.3.  Instead the protein is capturing them.  This distorts the relationship between pH and TA in a non-uniform way.
It will depend on the specific composition of the milk and the stage of acidity that has been reached. 
Comparisons of pH and TA therefore on a daily basis can help you extrapolate some physical properties of the milk you are working with – see the chart that follows.


Goats Milk Cheese in the Golden Valley

Before I got embroiled in the vegan debate, I was recounting a visit to Neal’s Yard Creamery.  It’s time to return to June and Herefordshire and in this post, lactic set goats milk cheeses.
Day 1 at Neal’s Yard Creamery and, bright and early, I headed into the dairy.  Charlie starts the day checking over the previous days cheeses and doing odd jobs: checking the acidity of the renneted buckets of curd from yesterday and ascertaining when to cut or ladle them, casting an experienced eye over already draining cheeses and levelling out where necessary.  I gave him a quarter of an hour to get going without someone asking a million questions (‘but why are you doing that? Where’s the such and such… ‘ etc) and then headed in.  Charlie was at work checking pH and ladling an experiment cheese he’s playing with.  Shortly afterwards, the next shift started and with the arrival of Ellen and (a little later) Haydn, ladling began in earnest.
All of Neal’s Yard Creamery’s goats cheeses are what’s called lactic cheeses.  This means that they acidify slowly and over a long period of time but ultimately to a high level.  On Monday morning, the cheeses to be ladled were Dorstone, the milk for which had been collected the day before.  Haydn had been in the dairy, added starter, left the milk to acidify and then at the magic pH point ( I could tell you but I’d have to kill you) had added rennet and left the buckets of curd overnight to set and continue acidification.  The following morning we were ready to ladle.
Dorstone curd is pre-drained, which means that before it makes it into the actual moulds that will give it shape, some of the moisture is removed by draining the whole lot of it first.  This used to be done in giant sacks that look for all the world like big curdy pillowcases and this is still done for Neal’s Yard Creamery’s goats curd but Haydn is experimenting when it comes to drainage and the Dorstone.  The drainage table was lined with plastic matting, curd ladled out onto and initial drainage commenced.  A few hours later, the drained curd will have salt mixed into it and will be transferred into cheese moulds which will then be turned out the following morning.
Meanwhile, in a corner of the room, Perroche curd was also being ladled.  Perroche curd is unusual for a lactic cheese because it is cut.  It’s very gently cut and in large squares but a few cuts are made and help get the moisture out.  These cheeses are only ever destined to remain fresh and rindless or in the case of the herb perroche, dusted with chopped dill, tarragon or rosemary.  Simple, but oh how effective.  My particular favourite, since you asked, is dill.  Sadly (for me) the sales on Perroche were good this week and there were none left after orders had been packed.  This meant none for me to buy.  Not in fact that I was allowed to buy any of the cheese I took home in the end, but I did try!
Mid-morning, Tim arrived with a fresh lot of goats milk, which was duly given a dose of starter and destined to be ladled out as Ragstones or Perroche logs the following day.  Meanwhile, Haydn was busy preparing more starter for the rest of the week and heating up cream for the crème fraiche (but more of that anon).  It is genuinely a hive of activity at Neal’s Yard Creamery but one in which each person has their own area and responsibilities and works efficiently away at them.  While all the cheese was being looked after and the crème fraiche being prepared, in a quiet, out of the way corner, Strained Greek Yoghurt was being poured into pots and maturing cheeses from the cold rooms were being turned.
The Ragstone milk is given its dose of starter as the Dorstone milk was.  In the afternoon, rennet’s added and the following morning it is time for acidity checking and ladling and so the routine continues.  Later in the week it’s the turn of cows milk, Neal’s Yard Creamery’s lactic double cream Finn and their Greek Style Yoghurt.  But that, is a tale for another day.

The Mystery of the Non-setting Sheeps Curd

After a summer and early autumn feeling like I got to grips with making some pretty good cheeses, the late season milk has thrown me a curve ball.  A lot is talked about seasonality in rather hazy, romantic terms of the terroir and what grasses or herbs or clover is available during the summer versus hay or silage in the winter.  Or even slightly more scientifically in terms of levels of fats and proteins in late season milk.  Very little, in my experience, is talked about in terms of temperature.We have recently had a head spinning turnaround from milk that set quickly and firmly (which we put down to high solids) to milk that just isn’t setting.  Fats and proteins aren’t dramatically different from the fast setting curd milk, there may be a little less calcium in the milk due to the grass quality not being what it was but basically that doesn’t seem to be the key issue.  Temperature.

For starters, the milk that had been arriving in the dairy at 27C or more in fact earlier in the year is now about 18C or 19C.  There are less sheep milking as more of them are served and those that are milking give less and less milk.  The body temperature of each sheep and the temperature of milk coming from each sheep hasn’t changed, but other factors mean the milk is much colder.  The sheep are milked before the cows.  The pipework is cold in the mornings now as it’s autumn and in addition it’s dark when the milking starts so what sun or daylight there is has had no chance to raise the temperature of the air or surroundings.  The milking system works by accumulating about 8 litres milk in a jar and then pumping it through into the dairy.  However it now takes longer to accumulate the 8 litres allowing the milk longer to cool as it does so.  It’s then pumped through cold pipes into the dairy.

Then there’s the room temperature or really to put it more accurately, drafts and currents of cold air.  If you look at the thermometer in the room the temperature hasn’t dropped massively and the heaters are going full blast and turned up as high as they can be.  However in the corridor where we do the packing the temperature is quite a bit colder which means that at this time of year, doors need to be closed to preserve the temperature in the dairy.

In the past couple of weeks the milk has gone from setting a bit too quickly because of its solids to setting very very slowly. Thinking back, the last of our fast setting milk was also at a point when the days were a little longer and then there was the brief Indian Summer when everyone went to the beach in October.  As the weather broke, the setting problems begain.  In looking at why this is happening (largely to me but it has happened to Martin too) we’ve looked very closely at the different ways in which temperature affects what we’re doing and how without us actually changing what we do, the parameters have entirely altered just because it’s autumn and we have less milk.

1. The milk is colder.  Any time it is left standing before the starter goes in, used to be a brief period of pre-ripening time as it was at 27C but very little is happening at 18C.  The lactic acid bacteria activity from the milk itself and from the starter once added is less even if the milk is heated and the starter added at around 31C because where there was a pre-ripening period, now there isn’t.  This in turn affects the quality of the set because the beginnings of acidification would free up a certain amount of calcium ions from the milk which helps for a good set and increases the yield.

2. The milk needs to be warmed up much more slowly and consistently.  To heat quickly, using the ‘flag’ or mini radiator type thing we use to warm milk (it works by running hot water through it) and stir the hot milk in, means it loses temperature more quickly.

3.  Even warmed more slowly, the milk doesn’t keep its temperature in the same way because there’s much less of it.  Whereas with quantities like 70 or 80 litres, the milk might drop 1 degree between adding starter and then adding rennet an hour later, it can now drop 2 or 3 degrees.  Losing temperature more easily again of course means the set will be weaker.

4.  The top of the curd, where you usually test the set, is colder than the lower part of the vat as it’s the area that’s open to the air the most.  Often this will set more weakly than lower down the vat.

Even by increasing rennet and trying to keep the vat next to the dairy’s heaters at all times after it’s been heated, the set just isn’t as strong as it has been.  The implications of this on the cheese are pretty huge.

1.  Weak curd forms a more sloppy substance going into the cloths.  Small and more mushy particles of curd clog up the cloths and reduce the effectiveness with which they let the cheeses drain.

2. Weaker and colder curd drains more slowly anyway.  It doesn’t free drain in the same way.  More cloth pulling only has a limited effectiveness as the cloths are clogged up already and also because with a weaker structure you end up losing fats and squashing the nutrients out of the curd by using more force but still finding that it feels soft and wet in texture.

And the effects of the weaker curd on the drainage cloths are:

Badly formed rinds because they are largely formed from the soft particles that collected on the cloths.  When salting or maturing further, these rinds are loose, too moist and come away from the cheese.

Cheeses that hold free moisture.
That old enemy we’ve been fighting with our draining cloths!  Because the cloths are clogged up, hindering drainage but also because the curd didn’t have enough resistance to the cloths to force out the free moisture when they were pulled up tightly and in the end slightly collapsed under the pressure we have floppier and less stable cheeses when they are turned out.  The effect of this is that the cheeses do not mature in a stable manner.  They don’t retain the calcium which will allow a full and elastic breakdown and they develop what is more of a lactic cheese texture with a very runny breakdown just under the rinds and a curdy, moist, acidic centre.  It’s not that this is unpleasant to eat, in fact it can be very tasty, it’s just not what we want.

Before I began making cheese, I might have tried to explain this to a customer by saying that at the end of lactation with the milk composition being different and the pasture being different, the cheese would change.  Having made cheese for a few months, I would now tell it very differently.  The biggest change has been the temperature.  So much for terroir!

Hospital Corners

It’s been a crazy few weeks since the last post on the 22nd May with Cartmel Races and Holker Festival pulling all hands to the shop and leaving me a cheesemaking flying solo a lot of the time.  However just because at the end of that I haven’t really had the spare brain to write anything, doesn’t mean that work has not been being done.  Far from it in fact.Shortly after the last post we had a visit from the Neal’s Yard Dairy crew which on that occasion were Bronwen (the buyer), David (one of the directors), Sarah (cheese maturation and allocation of correct age profile and flavour profile for each sales department) and Charlie who works in the shops.  They came with an issue to discuss – moisture levels in the cheese and drainage.  This of course was something we were looking at ourselves but the issues at NYD were that they were maturing the cheeses longer and finding on the cheeses from end of April that they became very very runny at the rind to the extent in fact that the rinds weren’t stable and fell off very easily if handled.  Unfortunately we hadn’t had that issue ourselves in our stores but certainly it was a problem.  We shared a few ideas about storage (are we storing drier than them?) and age of selling but ultimately didn’t reach a conclusion, especially as we’d made quite a few changes since the end of April already.  By the time of the visit we’d moved on from turning out cheese from the moulds onto shelves on day 2 to having a day draining on racks in the dairy in the moulds still then a day draining on racks again while 1 side is salted, then on day 4 finally making it onto the shelves for salting on the other side and then after that on day 5 a further day out on shelves to allow a nice coating of yeasts and fledgling B. linens to grow before they went into the cold store.  Since that visit we have also turned the cold store up a little so the temperature is warmer and the rinds develop quicker.

However having heard back from London and given that we’d been worrying about drainage now for a few weeks, I decided to go for advice to the dynamic cheese duo of Hodgson & Cordle (Randolph Hodgson & Dr Jemima Cordle that is) who had visited Martin earlier in the year to get him started with the MT36 starters and had given some advice on use of the cloth liners to the moulds to help get better drainage.  They had made their own test cheese and taken it away with them after the day but the experiment had made them both feel strongly that using the cloths enough was pretty key.

First off I checked whether they had done more cloth faffage (pulling really) than we were currently doing and at what intervals it had been done.  Pretty much the same as we were doing, yet their cheese had ended up pretty darn dry (admittedly partly due to being kept in an unrefrigerated and unhumidified environment but partly drainage) whereas ours most definitely weren’t.  It had also had a close knit texture and again that wasn’t something our cheeses were doing at the time – they were quite open textured.

Going back then to ask what they’d done differently, Randolph came back with the suggestion of pulling the cloths tighter.  He said ‘We are talking about hospital corners and taught sheets’.

The aim of the exercise therefore was to give a squeeze and put pressure on the curd rather than agitate it.  Fortified with the information I set off to give it a go the following day and pulled the cloths up so damn tightly that every morning still (as the cloth pulling continues to be tight) I have fingers that won’t bend properly from the muscles being so stiff.  And I have to say it did work and continues to work.  It also highlighted that we really needed new cloths as the older ones had weakened through use and were ripping with every cloth pull.  More were on order and in fact had been for a fortnight but the suppliers were being rather slow about getting them to us.  Even with daily chasing, it took a further 10 days for them to arrive!

So what has the change been?  Well there’s still the odd bit where the curd doesn’t knit together.  The problem with relying on cloth pulling so much for drainage is that if your tension isn’t equal across the cloth and the whole side of the cheese then you get a less drained area.  Sometimes the constraints of the space you’re working around on the draining table and number of moulds you need to fit onto it, just means that some are harder to get at and work with than others.  As a general rule though, they are more closely knit together in texture and certainly smaller at the end of the day than the cheeses I used to make.

We just had a follow up visit from Bronwen and the NYD crew this time with Joe Schneider (Stichelton cheesemaker for those of you who don’t already know) which meant our discussion had another point of view in the mix too and was very interesting.  Joe also uses cloth liners when draining his curd although they are used at a different stage and before the curd makes it into the moulds, but it means he knows what the aim of the exercise is.  That is, reducing free moisture (pockets of it in the open texture of the cheese) so that the starter bacteria can’t continue acidifying the curd as much and as a result the curd retains calcium.  If there’s enough calcium, the curd will hold onto moisture but it will be locked into the curd structure and will allow for the cheese to breakdown better during maturing.  If there’s too much acidity, the calcium dissolves and the curd, having lost its calcium, has less ability to lock in that moisture and it won’t break down so well.   Or to put in another way, here is what Jemima Cordle emailed to me as an explanation and I won’t try to paraphrase any further:

‘Basically the quantity of calcium left in your final curd along with the moisture content give you your texture. The more calcium you have the more elastic or rubbery the cheese will be. British cheeses contain less calcium than the continental types due to the fact that the curd that makes them loses its moisture over a greater portion of the acidity increase.  The curd that makes Comte for instance loses most of its moisture before the pH has dropped further than  6.5 whereas for cheddar to reach the equivalent moisture level the pH will have got down to about 6.0. The bit of chemistry that is important is that as the pH decreases calcium is released from the casein into the surrounding whey. As the whey is lost the calcium goes with it.
It is this loss of calcium that gives all our cheeses their characteristic textures so it is important to achieve. However it is very easy to overdo. If too much moisture is still being lost when the pH is much below 6.0 too much calcium will be released and the cheese will end up being chalky. It will also be dry because the decalcified curd cannot hold the moisture correctly.
More often than not this happens because too much starter is added so that the curd acidifies too quickly for the drainage to keep up and the moisture is not got out in time. In the case of St James, with the starter quantity you are using, this is not an issue as long as you give the curd the help it needs to drain.’
The help needed is those cloths and making sure they are hospital bed tight.
It’s been a fun & exciting few weeks as well as a crazy few weeks!
Cheeses just ladled and ready to start draining.  Photo taken on 21st May and I’ve been cutting and ladling smaller pieces since then too which also helps drainage.
Drained cheeses the following morning, also from 21st May.  The cheeses with cloths pulled tighter are about half the height of these ones.

And Introducing Swallet

This week saw the return of Swallet for a couple of days.  Swallet is a little disc of lactic set cheese which if all goes to plan has a creamy white wrinkled geotrichum rind and the recipe is more or less the Perail recipe but with a little adaptation.  The process actually takes a day and a bit until there is anything that looks like a cheese, but it actually requires not so much intervention from the cheesemaker.  Basically your job is to help the curd do what comes naturally to a certain extent.The milk is collected on the day of milking.  It is cooled a few degrees from the sheep temperature that it comes in at and starter is added.  It’s the same yoghurt consistency bulk starter that we use for St James and it is left then to grow and for the acidity to build.  A very small quantity of rennet is added that afternoon and it is left to set slowly overnight.  The following morning the curd has set and about 24 hours from the addition of the starter, we begin to ladle it out into moulds.  Each mould takes about a couple of ladles full of curd and it is then left to drain for about 4 hours before being turned in its moulds and then left overnight again to drain.  The following morning we turn the cheeses out onto racks and sprinkle salt over one side.  The cheeses are moved into a humid and warm room which has the right conditions to encourage the geotrichum to start growing and then turned and salted on the other side the following day.  After that it’s a matter of judgement as to when the cheeses are ready to move to a colder and drier environment once the rind has established itself.

Making Swallet basically uses the natural souring of the milk with a little help from additional starter and although a small amount of rennet is added, it also uses the setting ability of milk when a certain acidity is reached.  This means that actually these are technically fascinating cheeses because you are relying on the action of the acidity and the rennet enzymes to squeeze moisture out of the curd rather than, as with St James, cutting the curd to let whey out before ladling.  To be honest, it takes a bit of understanding, because there isn’t the same human intervention and it also relies on some quite subtle observations of the curd, in particular, ideally, monitoring of the curd pH which we aren’t able to do at the moment (the meter is broken).  The pH reading can of course correlate to observations on the appearance of the curd but it does take a practised eye.  Martin says it took him a few months to get his head round how to make it successfully and I suspect that may be the case for me too.  So whereas last week’s introduction to St James could be quite lengthy, this is very much just an introduction.  I have more questions to ask over the next few weeks as we make more of Swallet perhaps once a week if not even less and when I have got my head round what we’re doing a little better, I’ll return to why we do what we do.