Author Topic: how to use homemade rennet  (Read 4965 times)

Offline eric1

  • Medium Cheese
  • ***
  • Location: Iredell Co., NC
  • Posts: 37
  • Cheeses: 1
  • Default personal text
how to use homemade rennet
« on: June 21, 2010, 07:08:28 AM »
Hi! I butchered a veal calf last fall and saved out presumably the right part of the stomach, washed out the stomach contents, then salted it and placed it on a rack in the sun to dry out with a piece of glass above (to keep the flies off) and a screen below (to hopefully keep it from getting overly hot).  First, is there a better way to harvest/preserve rennet on a home-scale?  My main question, though, is what to do next?  I've had very limited success with my homemade rennet but I've been very pleased with those few seemingly random successes.  How do I know how much rennet to use?  I've stored it heavily salted in the fridge.  How long can I keep using it?  Do I need to worry about the salt affecting the coagulation or culturing processes?  What do I need to do to ensure that the rennet gets into solution?  Sometimes it seems like the rennet does nothing.  Even though it's calf's rennet my only successes have been with goat's milk; all my attempts with cow's milk have acted as if I hadn't added any rennet at all.  Maybe that's because I generally make larger batches of cow's milk cheese and I'm not adding a big enough piece.  I've tried soaking the piece in whey (left over from making ricotta) in the fridge for 12-24 hours and using the whey instead of the solid piece, but I'm afraid I have too many variables there to control: the acidity of the whey, temperature, time, etc.  In any case, I haven't had consistent success with that.  How did rural people make cheese 200 years ago?  I really want to learn how to make homemade cheese without store-bought ingredients, but I haven't been able to figure out how to use this rennet.  Does anyone else on this forum use homemade rennet?
Thank you!
Eric


Guests, join the CheeseForum.org community to remove this ad.


Offline MarkShelton

  • Mature Cheese
  • ****
  • Location: Cortland, IL
  • Posts: 378
  • Cheeses: 19
  • Aspiring vinter, hobby cheesemaker
Re: how to use homemade rennet
« Reply #1 on: June 21, 2010, 07:31:16 AM »
Welcome to the forum Eric!
This is quite an interesting topic, even though it is not practical for me (or presumably many others here) I am very eager to see how this turns out for you. I think its the degree of authenticity that thrills me about it.

Sorry I can't be any help with your questions, though.

What kinds of cheeses are you making?
I am constantly in awe of the very first people that consumed these things, despite how funky looking and smelling they had become.

Offline Alex

  • Old Cheese
  • *****
  • Location: Haifa,Israel
  • Posts: 732
  • Cheeses: 27
  • Default personal text
Re: how to use homemade rennet
« Reply #2 on: June 21, 2010, 11:16:09 AM »
Hello Eric,

Here you'll find some detailrd instructions:

http://biology.clc.uc.edu/fankhauser/Cheese/Rennet/rennet_preparation.html
Alex-The Cheesepenter

Offline Sailor Con Queso

  • Old Cheese
  • *****
  • Location: Kentucky
  • Posts: 2,542
  • Cheeses: 128
    • Boone Creek Creamery
Re: how to use homemade rennet
« Reply #3 on: June 21, 2010, 11:45:06 AM »
Wow. Is it really worth all that effort???
A moldy Stilton is a thing of beauty. Yes, you eat the rind. - Ed
www.boonecreekcreamery.com

Offline Alex

  • Old Cheese
  • *****
  • Location: Haifa,Israel
  • Posts: 732
  • Cheeses: 27
  • Default personal text
Re: how to use homemade rennet
« Reply #4 on: June 21, 2010, 12:24:17 PM »
Don't ask me  :-X, it's Eric's project
Alex-The Cheesepenter


Guests, join the CheeseForum.org community to remove this ad.


Offline eric1

  • Medium Cheese
  • ***
  • Location: Iredell Co., NC
  • Posts: 37
  • Cheeses: 1
  • Default personal text
Re: how to use homemade rennet
« Reply #5 on: June 21, 2010, 01:02:29 PM »
Thanks for the welcome. 

Lots of questions to answer.  First, about what kind of cheeses I've made, just
fresh cow's milk mozzarella
http://biology.clc.uc.edu/fankhauser/Cheese/Pasta_Filata/Pasta_Filata.html

ricotta
http://biology.clc.uc.edu/fankhauser/Cheese/Ricotta/RICOTTA_00.HTM

basic soft goat's cheese
http://biology.clc.uc.edu/fankhauser/Cheese/neufchatel/neufchatel.htm
(except I've found I like the texture better if I strain the curd as a whole over 24 hours without cutting -- I also salt the curd before straining)

and small curd cottage cheese
http://extension.missouri.edu/publications/DisplayPub.aspx?P=G9550

I'm eager to try making hard cheese once I can find time and figure out how I want to build a press.  What I'm most eager to develop is a recipe using home cultures (maybe just buttermilk?) and homemade rennet for a hard/semi-hard what I think would be called a washed rind goat's milk cheese that I can make a bunch of in the fall that I can age/cure (not sure on the proper terminology) in the fall/winter and eat off of through til the next year.  I milk a cow pretty much twice a day every day, but I'm more interested in the goat's milk for cheese, and I'd like to concentrate that work in the fall when I still have good forage for the goats but after the busy season is starting to pass.  Why, by the way, are there so few truly hard goat's milk cheeses?

I did follow Fankhauser's instructions more or less so far.  I certainly wouldn't have gotten as far as I did without them.  I'm still left with all the questions above, though -- and very haphazard, infrequent success.

As for whether it's worth all the effort, is anything that's done on a home-scale worth the effort?  It's certainly interesting, though, and I'm very interested in mastering the basics.  I feel like an admiral in the navy ought to be able to sail a sailboat, even if he's only ever going to sail a nuclear powered aircraft carrier.  And, if I'm going to go to the trouble, I want to do it all.

Offline linuxboy

  • Old Cheese
  • *****
  • Location: Ukiah, CA
  • Posts: 3,986
  • Cheeses: 199
  • www.wacheese.com
    • Washington Cheese Guild
Re: how to use homemade rennet
« Reply #6 on: June 21, 2010, 01:14:35 PM »
Quote
I still have good forage for the goats but after the busy season is starting to pass.  Why, by the way, are there so few truly hard goat's milk cheeses?

What goat cheeses are you familiar with? Most of the good ones are very small production, though, and eaten locally. You won't find them in the grocery store, they're not bulk commodities.
Taking an extended leave (until 2015) from the forums to build out my farm and dairy. Please e-mail or PM if you need anything.

Offline eric1

  • Medium Cheese
  • ***
  • Location: Iredell Co., NC
  • Posts: 37
  • Cheeses: 1
  • Default personal text
Re: how to use homemade rennet
« Reply #7 on: June 21, 2010, 03:41:37 PM »
What goat cheeses are you familiar with? Most of the good ones are very small production, though, and eaten locally. You won't find them in the grocery store, they're not bulk commodities.

I couldn't name very many, but I worked for a few years in a grocery store that probably carried 20 or more different goat's milk cheeses.  Majorero was probably the hardest cheese I can remember the store regularly carrying, although there was this little hockey puck cheese from mainland Spain, I think the name was El Cantu, that was the only really hard goat's milk cheese I've ever tasted.  It may have just been old and dried out by the time I tasted it, but I remember thinking it was delicious.  Are there goat's milk cheeses that are normally aged like aged cheddars or parmesan or aged goudas?

Offline linuxboy

  • Old Cheese
  • *****
  • Location: Ukiah, CA
  • Posts: 3,986
  • Cheeses: 199
  • www.wacheese.com
    • Washington Cheese Guild
Re: how to use homemade rennet
« Reply #8 on: June 21, 2010, 04:07:45 PM »
I think you're right, I haven't come across too many aged goat cheeses. Even for hard cheeses, I can only think of maybe 20 or 30 that are hard or semi-firm. Maybe a few more from artisan producers typically made as tomme or toma derivatives. Most of the great goat cheeses are not aged for very long or are lactic or semi-lactic set, like the many cheeses of France.
Taking an extended leave (until 2015) from the forums to build out my farm and dairy. Please e-mail or PM if you need anything.

Offline linuxboy

  • Old Cheese
  • *****
  • Location: Ukiah, CA
  • Posts: 3,986
  • Cheeses: 199
  • www.wacheese.com
    • Washington Cheese Guild
Re: how to use homemade rennet
« Reply #9 on: October 12, 2010, 02:44:30 PM »
I had no time to dive into this in June, but made a note to.

Hi! I butchered a veal calf last fall and saved out presumably the right part of the stomach, washed out the stomach contents, then salted it and placed it on a rack in the sun to dry out with a piece of glass above (to keep the flies off) and a screen below (to hopefully keep it from getting overly hot).  First, is there a better way to harvest/preserve rennet on a home-scale?

Yes, the way to do it is to first butcher at the right age. The age depends on the ratio of chymosin to pepsin that you want. The normal range is usually 15-20% pepsin, which is achieved by slaughtering at around 4 weeks of age.

Second, you need to either prepare the rennet as a liquid, paste, or dessicate and preserve the abomasum. To make a paste, you first grind with a commercial grinder to pulverize the heck out of the tissue with 20-30% salt, and then either freeze and use directly over time, or refrigerate and use. If you want, you can also activate the enzymes by decreasing the pH with HCl to around 2.5. This will increase your extraction rate and also help with lowering bacterial counts. Rennin exists mostly as prorennin in the abomasal mucosa and the zymogen is activated by a low pH and moderate temp (22-25C, pH 2-3). If you had any pregastric lipase from sublingual gland secretions, the low pH would inactivate it. Then raise the pH again with NaOH (titrate to know how much), and target a pH of mid 6s. Then you can use the paste.

To make a liquid, you can puree the paste and strain out the solids. There are commercial methods for how to get pure liquid, such as bacterial filtration, centrifugation, using acetone or other solvents, etc. But it's not necessary, you can strain through muslin and that would be OK.

If you dry, do it just like you did. Cut off all the fat, scrub, salt, and leave in a well-ventilated area so it dries out. Then to use, soak beforehand in whey (old traditional method) or an acidic environment to help extract the enzymes, and then raise pH again and use the liquid.

Quote
  My main question, though, is what to do next?  I've had very limited success with my homemade rennet but I've been very pleased with those few seemingly random successes.  How do I know how much rennet to use?

You figure out the activity by using an exact, small amount, and a volume of milk and calculating it against a known standard. So take some 200 IMCU rennet, and some of your rennet, and do a side by side and calculate the activity based on flocculation.

Quote
  I've stored it heavily salted in the fridge.  How long can I keep using it?

A long time, actually. The decrease in activity is fairly low, maybe 5%/year.
Quote
Do I need to worry about the salt affecting the coagulation or culturing processes?

Not really. It actually helps preserve things, and the concentration is not high enough to make a difference in the milk
Quote
  What do I need to do to ensure that the rennet gets into solution?

Pulverize, and/or extract in acid and then adjust pH to ensure extraction. Much of the zymogen (actually both prorennin and propepsin) of the enzymes are bound in the tissue, so using strips from the stomach is not really optimal. I suggest using a paste or making liquid rennet right away.

Quote
  Sometimes it seems like the rennet does nothing.  Even though it's calf's rennet my only successes have been with goat's milk; all my attempts with cow's milk have acted as if I hadn't added any rennet at all.  Maybe that's because I generally make larger batches of cow's milk cheese and I'm not adding a big enough piece.  I've tried soaking the piece in whey (left over from making ricotta) in the fridge for 12-24 hours and using the whey instead of the solid piece, but I'm afraid I have too many variables there to control: the acidity of the whey, temperature, time, etc.  In any case, I haven't had consistent success with that.  How did rural people make cheese 200 years ago? 

Most artisans used a paste, or would make a batch of the liquid and use it for the season. The inconsistency of rennet was actually one huge factor in cheese hygienic quality.
Quote
I really want to learn how to make homemade cheese without store-bought ingredients, but I haven't been able to figure out how to use this rennet.  Does anyone else on this forum use homemade rennet?
Thank you!
Eric

Let me know if you need more help. It's not so hard practically, but you do need some equipment to do it consistently. You can do it without fancy lab gear, but it's more challenging. Not impossible, though.
« Last Edit: October 12, 2010, 03:17:09 PM by linuxboy »
Taking an extended leave (until 2015) from the forums to build out my farm and dairy. Please e-mail or PM if you need anything.


Guests, join the CheeseForum.org community to remove this ad.


Offline eric1

  • Medium Cheese
  • ***
  • Location: Iredell Co., NC
  • Posts: 37
  • Cheeses: 1
  • Default personal text
Re: how to use homemade rennet
« Reply #10 on: March 28, 2011, 08:04:53 AM »
Linuxboy, Thanks very, very much for all the detailed information!  I just found your reply, as I haven't visited this forum enough lately.

In the meantime, I have had fair success (considering all the uncontrolled variables) simply putting a piece of the stomach in lukewarm water the night before (using a piece about 1-1/2" square for about 6-7 gallons of milk) and letting it sit out overnight.  (My most accurate scale only measures to 1/20th of an ounce, which isn't accurate enough for these purposes.)  Then I just dump the water in the next morning for my rennet. 

(The calf, by the way, was about 5-6 weeks old.  I figured younger might be better, but I wanted to realize meat value, too, of course.)

Your comments have me wondering especially about the ratio of chymosin to pepsin.  That's basically over my head, but it sounds like something I might ought to research.

Obviously, I haven't been soaking my dried stomach in an acidic medium either, like you recommended.  The idea of using whey sounds good, but I didn't know about using a more bacterially active whey like from yogurt; whey from ricotta seemed like a very good solution, but I don't make rennet coagulated cheese very regularly, so I mostly don't have any ricotta whey until the end of the process.  Maybe I should freeze it?  Can it in a pressure cooker?

If I used whey instead of water to dissolve the rennet, what about raising the pH again like you mentioned?  How would I do that in a homegrown/old-fashioned way?  Would adding it to the more neutral milk not suffice?

I didn't know about paste or liquid options when I did it, so I feel safe sticking to the dried method.  Do you think I should reconsider?  That would be a question for the next calf, anyway, right?

Thanks again very much!

Offline linuxboy

  • Old Cheese
  • *****
  • Location: Ukiah, CA
  • Posts: 3,986
  • Cheeses: 199
  • www.wacheese.com
    • Washington Cheese Guild
Re: how to use homemade rennet
« Reply #11 on: March 28, 2011, 08:30:53 AM »
Quote
ratio of chymosin to pepsin
Honestly, it's not a huge deal for your scale. Yes, chemically it does make a slight difference in terms of the cheese flavor. But very few people in the world could detect the difference in the cheese for rennet made from a 4-week-old calf and a 5-week-old calf. I tend to stick to 4-week old kids for my rennet, but that's a practical reason - it's goat kid rennet. With goats, I just cannot keep them from nibbling anything and everything (they usually start with eating decomposing wood at day 2), so their rumens develop quickly even at 4 weeks. It's also different for me, absolutely no meat consideration. The minis are maybe 10-15 lbs at 4 weeks, usually becomes a stock and/or specialty cabrito for the table. Even then, dairy goats, so it's a meal for maybe 3-4 people.

Quote
Maybe I should freeze it?  Can it in a pressure cooker?
I was just being practical because for most cheesemakers, having whey is no problem. The ultra traditional method is to save whey, soak the rennet, and then add the whey + rennet. You get culture and coagulant in one. You can also use lemon, vinegar, etc. You don't have to lower the pH dramatically, even down to 5.0 is vastly better than 7.0.

Quote
what about raising the pH again like you mentioned?  How would I do that in a homegrown/old-fashioned way?  Would adding it to the more neutral milk not suffice?
Should be fine. Or a tiny pinch of baking soda. Depends how acidic it all is. If you don't have a pH meter, try strips. If you don't have strips, use math for a theoretical calculation. And if you don't know how to do that, taste and/or guess. :)

Quote
Do you think I should reconsider?  That would be a question for the next calf, anyway, right?
Eh, up to you. I find a single batch, standardized, to be easier. That way, I only adjust once for the season of cheesemaking and use up the rennet, instead of measuring the grams each time. I try to eliminate variability. Also, the extraction for each batch will give you different amounts of enzyme, so it can be a little tough to predict. But you can mitigate this by using the flocculation method. In the end, do what's easiest. This should be about feeding one's family, and possibly making a livelihood as an artisan, so if you don't have a lab in your basement, then skip all the geeky stuff. It's mostly science to me, so I use ISO and other standards and make commercial quality product for myself.
Taking an extended leave (until 2015) from the forums to build out my farm and dairy. Please e-mail or PM if you need anything.

Offline eric1

  • Medium Cheese
  • ***
  • Location: Iredell Co., NC
  • Posts: 37
  • Cheeses: 1
  • Default personal text
Re: how to use homemade rennet
« Reply #12 on: December 13, 2012, 07:33:37 AM »
Linuxboy, I know it's been forever, but I wanted to thank you again for the advice, especially if I failed to do so already outside of the public forum.

I also wanted to give an updated report for anyone interested in my very basic experiments.  Based on Linux's advice I started adding just a little splash of apple cider vinegar to the half pint jar of water I normally soak my rennet in.  I haven't done anything in controlled scientific fashion, but that definitely seems to have helped with consistency and strength.  I used up the last of my calf's stomach about a year ago and have been using goat's stomach since.  I've made dozens of little batches of cheese since settling on my present method, and I think 100% of them have coagulated for me to my satisfaction.  I think the worst that has happened is that I carelessly added too much solution and wound up with an over-coagulated curd with a less desirable texture.  I might continue with homemade rennet like this for years or I may try to get more precise with regards to pH and dosage, but I'm plenty satisfied with my rennet for the cheese I'm making currently.

Offline MrsKK

  • Old Cheese
  • *****
  • Location: Wisconsin
  • Posts: 1,875
  • Cheeses: 61
  • Default personal text
Re: how to use homemade rennet
« Reply #13 on: December 13, 2012, 08:48:26 AM »
A cheese to you for your persistence!  I, too, like to try to make things from scratch, at least once or twice to know if it is something I'd want to add to my list of skills.  I've not tried homemade rennet yet, but will probably do so in the future, so I'm glad you have reported your success.