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GENERAL CHEESE MAKING BOARDS (Specific Cheese Making in Boards above) => INGREDIENTS - Lactic Acid Starter Cultures => Topic started by: Alpkäserei on April 09, 2014, 10:55:34 PM
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This evening, I started the production of my starter culture for this season. On Friday I aim to make either a Mutschli or a Raclette with this culture, which takes 2 days to produce.
The concept of this culture is, I am isolating native bacteria out of raw milk in order to make cheese in the future. There are two basic ways to do this, using the 1-day or the two day method.
I am using the two day method, where a quantity of milk is prepared and incubated, then used to culture a second-round of milk which will be used to culture the cheese produced on the third day.
The one day method just places the product of the first day of preparation directly into the vat to make cheese.
The two day culture is stronger and more diverse,
the one day culture is safer because there is less opportunity for the culture to get infected or contaminated.
This time of year, 2-day cultures are pretty safe.
The process I used is, (all temps. are Celsius)
take 1 quart of raw, uncooled milk. I got mine straight from the cow and made it immediately into culture.
This milk was flash heated to 61 degrees
then IMMEDIATELY flash cooled to 42 degrees.
I allowed the milk to rest for about 2 or 3 minutes, then repeated the process.
This was done a total of 3 times, BUT
on the last round I heated up only to 55 degrees and cooled down to 40 degrees.
Now the culture is incubating in a thermos.
The theory is, this treatment will isolate streptococci pretty well, giving me a good lactic acid starter.
Tomorrow, I will start the second round. The second round will serve to diversify the culture, and get some lactobacilli into the mix. This is accomplished by not treating the milk as thoroughly.
In fact I will actually make two batches, in one I will inoculate milk that has only been heated to incubation temps. In the other, I will inoculate milk that has been heat treated once.
Doing this, I will have one batch that has a diverse flora and let it set, and I will have another that gives the streptococci a chance to get stronger. I want these to be my strongest strain after all.
On the third day, the two batches will be recombined, and a certain amount will be added to some milk perhaps an hour before I start making my cheese.
I will make probably a 20 gallon batch, for this I will use 1 pint of the finished, mingled culture.
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one of these day's I will understand all of what I just read :-\
I will just have to remember where I read it 8)
AC2U for your lessons in this area of expertise
I love this stuff!!!!
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Also a cheese from this side! I certainly want to try this once myself since I've access to raw milk, right from the cow.
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I changed my approach for day 2 slightly,
I took the culture out and tested it at about 11:00 this morning (having started it 6:30 last night)
Then combined the 1 qt of culture with 2 qt raw milk
Then I flashed the whole mess up to 60 and back down to 48
notice here it is at 48, not 40. This like, 114 F or so.
This is more in the range of what will get Lactobacilli to grow, but also strep will grow in this range.
I am going to allow this all to ripen for a few hours, then later this afternoon I will separate it into 2 batches.
First I will flash up to 60
then back down to 48
then I will take of 1 qt and set it aside to incubate, this time going for about 24 hours
Then flash back to 60, down to 42. This time 42, because my bacteria doesn't seem to be quite on track yet.
Then I set out a quart of that to incubate, again for abut 24 hours.
The first part will favor lactobacilli. The hope here is that I can get a good portion of LB to grow
The second part will favor streptococcus. The hope here is that I will get my strep kicked into gear and ready to go.
The two will be blended back together tomorrow immediately before use. The exact proportions depending on the acidity of the final product.
I use titration to test acidity, or percent of lactic acid in the milk.
Today, my culture tested out at about 12.9 degrees SH, or .29% LA. So the acidity is very weak at this point.
I will use the culture once it falls into the range of 35 to 45 degrees SH, or about .79% - 1% LA.
The target for a culture produced from whey is around 28 degrees SH or about .63% LA.
We push the acidity higher when we start out, because the culture is not as viable at this stage.
After we have made cheese with it, it is much stronger.
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For reference,
a TA as high as say, .17% could just be due to the natural acidity of raw milk, due to the proteins, etc.
Having achieved nearly .3%, I know I am growing bacteria.
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Oh wow! just, wow! A cheese for you indeed!
Quick question: is acidity level the only measurement you need to know the development stage ("strength" or "potency") of the culture? Would PH levels work or is tritration more accurate?
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Eric,
Alp is essentially making a Mother Culture and using specific temperature targets to naturally select for Streptococcus thermophilis and Lactococcus. Above 105F the mesos start dieing off.
With a MC, there is a fine line between optimum bacteria count and over-acidification, especially with thermos like Strep. Initially the bacteria produce acid, which coagulates the milk, sort of like yogurt. If using a pH meter, I shoot for around 5.0. However, if you just monitor the progress of the coagulation, the whey will start separating when the culture starts to over-acidify. You want to stop incubation just before this so the culture will be as robust as possible.
In Alp's case, the process is MUCH slower and deliberate than the way that I make MCs because of the low number of bacteria that are initially introduced from his raw milk. Milk is technically sterile, but native bacteria are picked up from the teats, etc during milking. Once he has his "starter" going for the season, he will transfer these bacteria from batch to batch as a perpetual source of starter bacteria.
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Thanks for pointing out the source of the bacteria. That's important, the bacteria is not technically native 'to the milk' but to the environment. That's why clean practices are SO important...
Checked my culture at 5:15, pleasantly surprised to find it had noticeably thickened. Actually I was worried at first at had set overly fast, but when I stirred it back up the thicker top portion blended back in and it is still liquid.
Titration shows I am at about 16 SH (.36% LA) So I am about halfway to where I want to be.
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Thanks for the great info, Sailor!
This thread is opening my eyes to one day try and make a "self-sufficient" cheese project (with the help of a cow or goat of course ;) ) where I'd make my own vegetable rennet with nettles and thermo culture using this technique with raw milk.
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And here is the reason for the afternoon ripening...
When the milk is heat treated, having reached a certain level of acidity, the solids will actually solidify out of the milk much like making cheese
Actually I was very surprised by this batch, that the solids actually solidified almost like a rennet set cheese,
after heating the milk up, the curds could be cut and stirred
My target was to get whey for the purpose of producing a strong culture, and of course if you have whey you also have curd,
So I went ahead and strained the curd off after taking out 2 quarts of whey, and made a tiny little cheese out of it.
If I had just let the milk go, I would have wound up with yogurt, but having heated it up I forced the curd to contract and form a more solid curd.
Surprisingly, the whole formed into a mass much like a hard cheese, despite the lack of rennet.
I don't know what this will turn out like, the cheese is just a byproduct...
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Day 3,
culture is ready to be used, if I want to
Change of plans, I won't be making cheese today.
2 parts of cultures tested out at 41 and 32 degrees SH, they were blended back together at about 12:30 and have been marked and frozen for preservation.
They passed the acidity test,
and the taste taste
The culture tastes terrible. That is, it is very strong in the flavor of lactic acid.
Since I froze the culture, it will be used like a mother culture to restart a batch of live culture later on.
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I'm in awe....
Tres cool.
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Fascinating.
A cheese to you Alp, for your approach. I'll watch with interest to see what the results of the cheese you make from this are.
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The byproduct cheese tastes pretty yeasty
I don't know anything about lactic cheeses, so I dont know why that would be the case
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Herr Alp, this is incredibly cool, and I was just mentioning this possibility on another thread.
The cultures you get from this method: since they're wild, do they have a tendency to be stronger, long-lasting, possibly true heirloom cultures?
Since I have no real means for flash heating or snap cooling in my house, I suspect I'd have to vary your method if and/or when I tried doing this myself. Not sure whether you've had any experience capturing a wild culture this way - I suppose it would lift the risk of infection several points simply because less of the bacteria living in the milk would be knocked out - but I'd love to hear if you have any experiences with making wild culture this way :)
This year I'd be interested in trying a Gamalost recipe (http://home.centurytel.net/thechronicle/ (http://home.centurytel.net/thechronicle/)), which pretty much relies on a a similar principle - a milk that naturally curdles is left to age for months and months. Or, as some old Norse dude says: 'Take some cheese, stuff it in an old sock bury it in the manure.... and when it is ready it will crawl out'. This account is perhaps somewhat.... embellished. Nevertheless, it seems like an interesting challenge.
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I've a question, relevant (I hope) here. Many discussions I've re-read, now, discuss the lactobacilli-emphasis (over ST) of swiss gruyeres, its cousins, and in particular, Beaufort (one source saying, in terms of added culture, only helveticus is used). This was news to me. Your whey make crash heats up quite high, which is intended to isolate out ST, Alp - yet sources I've read indicate ST is preferentially incubated at 42C, while the lactobacilli thrive better at higher temps, 45C and up.
Is it the case ST is simply less heat labile, so while it won't thrive at higher temps than the lactobacilli, it can withstand high heat like this for a short period, better than the lactobacilli?
Secondly, if doing a make like we're talking about, after your crash heat/cool regimen to isolate out ST (presuming we're still on the same page that indeed, this part of the process does preferentially grow ST - lower range of 40-42), given the preponderance of the literature discussing the lactobacilli predominance, couldn't you add in a good store-bought yogurt (Chobani seems great to me - S. Thermophilus, L. Bulgaricus, L. Acidophilus, Bifidus and L. Casei. Used it last time and the whey starter was excellent), then wouldn't you incubate at 45C or higher, for the final round?
The only other thing I wonder with this, is if 45C is too hot for the ST. I seem to recall somewhere that given the lactobacilli prefer 45 and up, and ST prefers 40-42, that 42C is a good compromise to preserve a healthy, diverse thermophilic flora. Is this the logic, Alp, for going 42C?
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Hoi,
that's a complicated question
Linuxboy is the right guy to answer that question, but he's on hiatus so I'll do my best
You are absolutely correct, the temp ranges for incubation favor ST. That's the point. ST can be tricky to get started, if left to spoil for example ST usually won't be what curdles milk.
Our goal is to target the native ST, and get it jump started and to develop a strain that is well adapted to the processes of cheesemaking.
What we want is to get ST for early acidification, so that our cheeses will reach their pH in the right time frame. Fortunately for an alpine make, acidification rates really aren't that important. We are going to remain above 6 the whole time during the make.
It was explained to me like this,
Lactobacilli are the most important flavoring element. IF you use pasteurized milk, you need to add a good deal of them. So tha's why when making gruyere, etc. you need to add a culture with a good LB strain in it (it actually doesn't matter which LB strain you use. Everybody think Helveticus is the right strain for Alpines, but guess what in Switzerland they use Delbrueckii. They all behave similarly, close enough for our purposes, and produce the same byproducts, ie. flavor.)
BUT if you use raw milk, it is full of natural LB. In fact, Pav told me once you really don't even need to add any at all. I like to though, because I want to get as much LB flavor in there as possible. The Alp where I learned, we added yogurt to get stronger LB in the culture, and the flavor was more intensely nutty and spicier than other Alpkäse from nearby Alps, that's what I want.
But the thing we have to remember with bacteria growth and flavor is, if it is strong enough to beat out other bacteria it really doesnt matter how much you add. Bacterial rates at startup almost don't matter, all that matters here is that your bacteria are numerous and active enough to beat out any other competitors. That's why we add a starter instead of just letting the milk ripen for a couple of hours by itself. The rate of reproduction past the first few minutes depends almost none on how numerous they were to start (in an ideal environment, bacteria doubles its population every so many minutes, depending on strain) what matters more are conditions (the doubling rate is quicker at ideal temp ranges) food supply (again, they reproduce faster witth more food) and competition (competitors take away food, and may attack)
Remember a bacteria reproduces by dividing themselves, so that's why the population doubles.
So if you are following me here, timewise we are behind a very small amount if we started with half or even 1/4 as many bacteria in our cheese, because the cycle is pretty quick.
SO I guess the simple answer to your question is,
If you are using raw milk and passing down a whey culture, yu don't need to add LB from any outside source. But you still can, just keep in mind that the added LB will make your cheese sharper quicker (also, drier quicker, and potentially sour) Alpkäse is actually quite sour because of the strong LB growth, but you can hardly detect the sour over the salt and spiciness.
If you use processed milk, you need to add LB from some source. You can use yogurt, that's what we did on the Alp. That's the same reason why I cultured a second batch at a higher temperature.
Despite the high temps used in treating the milk, ST and LB both should have survived from your milk. They are both very heat tolerant bacteria with thick cell walls and good natural defense abilities. These two bacteria are the reason Alpine cheese works, where part of the process is to cook the curd up to a point where pathogens die, but these two workhorses survive.
So our culture actually has LB in it, but by incubating it just below LB's favored range, we ensure ST is stronger.
ST will grow at 45C. I make yogurt at that range some times. But LB will just grow a little faster.
The logic for incubating at 42 is so that ST gets stronger. We are really trying to wake up the ST to get our early acidification (that is, the first two days of the cheese's life) the LB has months to get going, we don't need to worry about it too much.
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Cool. Yep, I think I get it, Alp. I'd call my first attempt at your whey culture regimen a success, so I'll hold to it, for now - adding in good yogurt after the few rounds of ST isolation and incubation at 42C. I think where I was going with the notion of edging a bit higher was after these ST rounds...so:
day 1, heat/cold crash x 3 and incubate at 42;
day 2, heat/crash once, once cooled to incubation temp add in yogurt and incubate at 45 or slightly higher.
-presuming ST is still quite strong, but now, LB is also optimally encouraged. One issue I see, is that that same text discussing these whey starter temps, indicated 42C yields a much more diverse flora than 45C. So especially if this is all just a starting point (no pun), and it's the repetitive process makes of the cheese that will set the flora and their ratios, I'm probably overthinking this. 42C is just fine, yes?
Interestingly - and I missed this from my first reading of the Polytech'Lille material - but not only is Beaufort higher in fat, higher in salt and lower in propionic than Comte and Emmental, but it's higher in lactic - by a huge margin: 12-16 g.kg^-1, over 4-6 for both Comte and Emmental. It is, however, lower in acetic acid than either of the other two (not by much: 0.5-1 for Beaufort, 1-4 for Comte, 2.5-5 for Emmental). I associate acetic acid with a definitively "sharper" character, so this mix of acid concentrations is quite interesting to me - particularly the almost outlier-like nature of Beaufort's lactic acid content.
Edit: Whoops, just saw your amended Day 2 process. I like the approach, I think this is what I was after, getting both a strong ST and LB by temp optima. I was trying to do it it one culture, and I see you just split the culture, incubated each for ST and LB optima, and reblended. I get it. Thanks, Alp!
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Yes,
and also since I heat treated partially acidified milk, I forced the solids out of it and essentially made a whey culture.
This is good, because a whey culture is easier to control, easier to store, and generally safer.
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What makes the whey culture easier to control/store/safer than a "yogurt?"
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What makes the whey culture easier to control/store/safer than a "yogurt?"
<<Le bump>>. Alp, I'd say, customers would be dying to know - but I'd prefer not killing them to find out, you know? Can you indicate the reasoning on this, why a whey would be essentially better for these reasons than a yogurt?
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Mostly because it is a liquid, and it remains a liquid. It remains more or less homogeneous, and it is easy for bacteria and their byproducts to easily disperse throughout the whole.
Since milk gets thick, and separates out into two parts as the acidity increases, it can be a little more difficult to work with. Also with yogurt, I can't strain out the less desireable parts of the culture (some of the solids that precipitate out) that impact cheese quality.
Also when I do a two part culture, I can easily reblend the two parts because they are liquid.
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OK, thanks. I was just thinking of mother culture, as I used to do it, with Sailor's idea...if it dropped a bit low and I got some separation, I just agitated it and added that. But I get what you're saying here.
Still a bit unclear on the safety aspect, why a whey would be a better safeguard?
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I'm loving this thread! Thanks. Can anyone suggest good reading material as background reading about the processes etc involved in making cultures from scratch?
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Paul, with what level of complexity in the content? It's basic biotech process in the end, but it can be very complicated if you want to be precise.
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I have a science background so technical stuff is fine but I'm more interested in understanding basic processes and procedures. A ' beginners guide' is fine to start. I'm not so interested in the biochemistry level - something for an advanced practitioner maybe, if it exists. Thanks.