Using Kefir as a starter

[ekocheesegirl]

Hi,
I have been working with cheese since June on a small farm. Trying to go natural as often as possible.
For a long time we have been using Kefir as a starter (inspired by David Asher) a long way it went good, but lately we have had some yeasty cheeses. A lot of small holes throughout the cheeses and a yeasty smell and taste. (we found out that we should keep our sourdoughs far away form the cheese kitchen - yikes ) But now we have moved all that could contaminate, then our kefir still seems to contain too much of the yeast. I know that kefir contains yeast cultures naturally, but we are trying to make it more bacterial again.

Have anyone tried anything like it? Any good advice?

[Bantams]

The advice to keep sourdough away from cheese is a bit misleading, as bread yeasts don't readily colonize milk on their own.

If you're experiencing lots of tiny holes, swelling, and off smells/taste I would consider coliform contamination in the raw milk, vs yeasts from kefir.

This might be helpful:
https://www.readkong.com/page/cheese-defects-the-blowing-defect-2479108

[mikekchar]

I should keep my mouth shut, but...  Using kefir for making cheese is *not* natural.  It's *very* unusual.  That's not to say that it won't make good cheese!  I'm sure it can and does make good cheese, but like many things in David Asher's book, I think reality diverges from his imagination of how things work.  It is not uncommon for kefir based cheeses to start producing gas.  Some of the yeasts in kefir definitely produce copious quantities of gas in milk (as can be seen when drinking kefir :-) ).

Raw milk cheeses are almost never made using starters similar to kefir.  I won't say never, because there are definitely clabbered cheeses.  However, the vast majority of raw milk cheeses (really, really close to 100%) are made from whey cultures.  With whey cultures, you clabber the milk and make a cheese from it.  Then you take the whey from the cheese and make a "mother culture" culture from it (essentially yogurt). Normally the milk for the mother culture uses pasteurised milk because you want to strengthen the bacteria that was most active during the cheese making process for your initial cheese.  Then you make a cheese from the mother culture, giving you whey again.  Generally you use the whey for your culture from that point, occasionally making mother cultures.  Often you maintain several mother cultures.  With Yorkshire Wensleydale the PDO spec actually specifies that you *must* use 6 mother cultures.  The mother cultures are mixed based on their fermentation properties, a cheese is made and whey produced.  The whey is then used for culturing the milk for making cheese.  However, the idea is that you are constantly making your single type of cheese and reducing the number of types of bacteria in the whey, while strengthening the main cultures.  For alpine cheeses, they heat the mother cultures to kill any bacteria other than a few that can survive at high temperatures.  Parmesan takes this practice to the extreme by cooking the curds at 55C in every make.  The result is that there is literally only a single strain of bacteria that survives after a few cheeses are made.

To be frank, the whey cultures maintained by the cheese makers are basically *identical* to the DVI cultures you buy in a pouch.  Literally, the culture manufacturers get whey cultures from famous producers, isolate the bacteria in it, breed it up separately in mother cultures, freeze dry it and then mix it.  But it contains literally the same bacteria and there is nothing unnatural or even unusual in what they are doing -- it's just more labour that results in a slightly more consistent product.  Cheese makers (even many famous raw milk cheese producers) use DVI cultures in their raw milk cheeses because it is much less labour for them.   (Aside: I suppose freeze drying might be slightly unusual, but it's no more unusual that drying out your sourdough starter, sticking it in an envelope and mailing it to your friend.  If you think *that* is unnatural, then I suppose DVI cultures are also unnatural).

If you want to make raw milk cheese the traditional way, using whey cultures, it's a *lot* of work.  For one, you have to make cheese every day.  Cultures don't survive in whey for a long time.  They whey eventually gets too acidic and your balance gets thrown off.  Asher concedes this in his book, but then just slides past the elephant in the room.  The balance of cultures in kefir is fairly stable, but *not* what you want when making cheese.

Kefir is legitimately kind of magical.  Nobody knows how the original kefir came to be.  You can only make kefir with kefir grains.  There is no known way to start with bacteria and yeasts and make new grains.  It's  a miracle.  But it's not immune from from nature itself.  Kefir is a self sustaining colony of bacteria and yeasts.  It's self sustaining, but it is *not* optimal for your cheese.  While there are lots of bacteria that you want in you milk, it is *not* in the proportions that you want.  Using kefir is *not* a substitute for a whey culture by any stretch of the imagination.  It's just a convenient way of maintaining a culture that you can make cheese from without much work.  It's an incredibly clever idea, but it is *not* the way cheese has *ever* been made traditionally.  It is not any more or less natural that any other way of maintaining a culture -- it's just less work.   It's not an ideal way of maintaining a cheese culture.  It's just less work.

I get frustrated because David Asher's book promises a lot, but delivers little.  Most of what's in it is just plain wrong.  I don't mind that so much.  Most home cheese making books are basically full of wrong.  The only book I actually recommend is Gianaclis Caldwell's book, because while it has errors they are mostly transcription errors -- not a complete misunderstanding of the topic.  My main problem with David Asher's book is that not only is it wrong, but it's paired with a poisonous invictive intended to belittle every approach other than his.  I will only tolerate that kind of writing if the author is right, but Asher's book isn't even close.  Having said that, it's probably got the best collection of easy to use beginner recipes of any book I've seen.  He basically only has 2 recipes in the whole book and just recycles them with different application.  It works incredibly well for making simple cheeses.  None of his recipes are close to their traditional counterpart, unfortunately (despite his assertions -- the hubris expressed in his cheddar recipe is painful).

I'll stop ranting.  It's not the first time I've ranted about this book and it probably won't be the last.  Sorry for inflicting it on you!

[ekocheesegirl]

Hi, both of you.

Thank you for taking your time. I appreciate your answers.

We have been considering the coliform contamination, but the yeasty smell and look was just so clear, that we would try to eliminate that first.

We have been considering other cultures than the kefir, as you state, it is not the traditional way to do it. But it has worked great up untill now. We are working on the whey culture, but have also had success in using our buttermilk for some batches, and have had some really tasty cheese. : )

As I mentioned we are new to cheesemaking, and DA has been a help to open it all up for us, and made an easy guide. He might be wrong in many ways, but we have been happy for his natural approach to the whole thing. Then we can live with the maybe not traditional thing about it for now. Maybe when we get more skilled we can work more traditional with it I guess.

Thanks again. I think we will look more into working with our own mother-cultures. We already do keep clabbered milk, both to eat, but also to keep the culture, so we might work more on that. Thank you mikekchar. I appreciate your long and deep answer : )

Best regards
Ekocheesegirl

[FishFarmAndy]

Hi ekocheesegirl and mikekchar

Not sure if you're still reading this thread but I found the comments on David Asher's book interesting.

I've tried kefir as a starter for a dozen successful cheese makes now, perhaps better than my previous ones using a general-purpose mesophilic culture. Reading DA's book for the first time I sort-of assumed there was a kefir starter tradition somewhere but, re-reading, perhaps it is his invention. Does anyone know more on this?

What I would say on kefir for this purpose is that there are various things you can do to make it more uniform, batch to batch, which will surely affect the cheese made from it. If there's still interest in this thread I can explain how I keep my kefir stable.

[mikekchar]

I don't know more than I've already said.  There is a commercial cheese made with kefir, but it's very new, not traditional.  I suspect there must be *some* traditional cheeses based on kefir that originated in Cacasus mountain area.  Literally 0 popular cheeses of European origin have traditionally been made with kefir.  Keep in mind that kefir has not really been available around the world for much more than 100 years.  So there was no chance of it ever being used for those traditional cheeses.  David Asher's application of kefir is definitely his own invention.  I feel that it's a pretty clever invention (like a lot of his inventions).  I chafe at his incorrect assertions, not his cleverness :-)

Please do talk about keeping your kefir stable and appropriate for making cheese.  I, for one, would find it very interesting.

[Gregore]

I actually kind of liked David's book , while reading it I finally got the picture of how easy cheese was to make ,  before that it felt so technical and course it can be but it's not necessary. I made a few kefir cheeses but did not like the funky after taste of them if I aged them any more than a few weeks . 

Also had kefir ruin a mini cheese fridge , my wife stored her back up kefir culture in my fridge  for 6 months or so and it's cultures started to prosper in the walls of the fridge and contaminated all my cheeses .  Tried  taking it apart and bleaching every surface , had to give it away .

[mikekchar]

> while reading it I finally got the picture of how easy cheese was to make ,  before that it felt so technical and course it can be but it's not necessary

Having read many of your excellent posts, Gregore, I have a had time believing you have problems with technical things  But I agree this is the absolute best part of his book.  Honestly, I wish he had written a small booklet with only that content.  It would be awesome!

[FishFarmAndy]

On DA's book again, I too liked the simplicity of his recipes. Before that I was forever wondering about the differences between Caldwell, Thomas or some online source's particulars for a given recipe. I always wanted to know why, especially having taken to heart Caldwell's teaching of general principles and categories of cheese. Most of my makes are hybrid recipes from notes that I've made from 2 or 3 sources plus experimentation with things I think might make no difference or a positive difference. DA helped me simplify and learn more effectively.

For kefir I'm using 'grains' passed to me in the UK by an Italian, originating from others in her family back home. They seem more stable than others I've used over the last 5y or so and grow much larger, up to a couple of ounces is common. After variable results with the various other grains I'm now following these principles, influenced by my Italian friend:

• keeping as close to 20C/68F as possible, never refrigerating
• limit the microbial content of the milk so that the grains mostly determine the result, by this I mean heat-treating raw milk (85C, 10mins, rapidly cooled) or even UHT milk. Shop milk or plain raw milk gave me variable results
• 24h cycle, even if result is non-ideal; the health of the grains is the most important thing
• if you have to store the grains, freeze them in a minimum quantity of milk. It's possible to dry then rehydrate too. Don't just refrigerate as that alters the bacterial balance (less LAB, but I need to check up the original reference paper for that)
• for cheesemaking I use freshly strained, 24h fermented kefir at one cup per 4/5gal. The kefir is thick, creamy, moderately sharp but not fizzy or too acidic in the way older kefir can be.

[mikekchar]

Interesting.  This is really similar to what I've started doing with my mesophilic mother cultures.  In fact, practically identical :-)  Temperature is really key, I've found.  The speed that it acidifies determines the ratio of various bacteria it seems (for the multi-bacteria starters, which I tend to do).  Also, limiting that final pH is really important because some of the bacteria really doesn't like low pH (especially the gas producers, it seems).

Here's a trick that I use that should also work with kefir.  It goes against your "do not refrigerate" rule, but I wonder if it might still be useful...

Curds form due to acid at a different pH depending on the temperature.  You can test this out yourself pretty easily by heating some milk to 55 C and then adding enough vinegar to get it to curdle (make sure to measure how much vinegar you are using).  Then do the same thing with 20 C milk.  The 55 C milk takes a *lot* less vinegar.

At about 20 C, the pH where the curd forms is somewhere around 4.7.  At 55 C, it's about 5.4.  These are estimates!  I sadly don't have a pH meter to test this and I've yet to find a table for it anywhere on the internet.  :-(  If anybody with a pH meter can test this, I would be incredibly grateful.

What I do is pick a temperature based on the final pH I want to reach (using the temperature as a proxy for the pH measurement) and then watch the milk coagulate carefully (usually I'll let it go for several hours and then near where it's about to gel, I'll check it every 30 minutes or so).  As soon as it gels, I pop it in the to refrigerator to slow down fermentation.  This gets me pretty close to a consistent pH each time and it will stay closet to that pH overnight, anyway.  Then repeat the next day (I actually do it every second day and it still works pretty well).  This gives me a lot of control over the characteristics of the culture.

The downside to refrigeration is if you hold it there for too long.  There will usually be *some* bacteria that's totally OK chugging along slowly at 6 C.  The pH will tank and your nice balance will be broken.  Luckily, it's usually pretty easy to bring it back -- you just to 2-3 cycles and it will come right back.  I came to this insight based on a paper that Aris showed me.  The bacteria in the mother cultures seems to tend towards a small number of bacteria.  Even inside a raw milk cheese (that had a starter culture added to it), the bacteria that survives is exactly the same as the starter culture.  The proportion of the bacteria changes as the cheese ages and as the pH of the the cheese changes, but they just kind of bounce up and down.

I've been spending the last 6 months or so experimenting with mesophilic starter cultures derived from actual commercial cheese and I've found that it really seems to be true.  You get cultures that are typical of the original cheese.  Not only that, but the yogurt/buttermilk that it produces is really interesting -- much more variety than I would have expected.

Anyway, sorry for the diversion.  I suspect the reason your "do not refrigerate" rule works so well is that the yeasts in the kefir do a good job of balancing out the pH.  If you refrigerate, then the yeasts are affected more than the bacteria and it slowly acidifies in the fridge throwing off the balance. 

[Gregore]

Actually I do have a problem with certain things technical and chemistry is one of them , for years it all went in and got lost some where inside my head

but more to your point about the book , before reading David's book it seemed to me like cheese had to be a very technical and complicated production , and it very well can be , but what the book really opened my eyes to is how simple it can be as well as it can be an art or a production .

It really is so easy a caveman can do it .