Testing rennet

[tananaBrian]

Using Ricki Carroll's method of testing the viability of rennet, my rennet (or milk?) didn't seem to work as well as it should?  Here's what I did ...maybe someone can comment and tell me if the results were normal or not and whether or not my rennet is aging (it's a recent purchase but who knows how long the store owned it or how it was stored?):

The Method:
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- Mix 1/4 tablet rennet (crushed to a powder) in 8-oz cool water and let sit for 10-15 minutes, stirring now and then.
- Heat 8-oz milk to 90 F.  For testing only, I used 1% pasteurized homogenized (label does NOT say "ultra" anywhere on it) milk microwaved in a pyrex measuring cup.

- Mix 2 tablespoons of the diluted rennet solution into milk (just a few gentle stirs)
- Wait 2 minutes ...the coagulation should be starting, e.g. a 'film' on top of the milk (as described by Ricki)
- Wait 4 more minutes (6 minutes total) ...the curd should be at the clean break stage now

The Results:
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- At the end of 2 minutes, the milk had the same character it had right out of the jug
- At the end of 6 minutes (total), the milk was curding, but very soft and not anything close to a clean break, more like watered-down soft yogurt.  Temperature check said 86 F (ooops...)

- I put the milk in the microwave for 30 seconds.  Temperature came up to 91 F and the milk took only another minute or so (maybe 2 minutes?) to form a nice white curd with clean break.

Conclusion (mine):
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The action of the rennet seemed slow to me, but then again, restoring the heat a little bit seemed to kick things off.  Maybe using 1% pasteurized homogenized milk slowed things a bit?  Sure did get a picture-perfect curd when it finally did curd though...

Comments?

Thx,
Brian

[linuxboy]

What exactly are you trying to figure out? The strength of your rennet in quantifiable IMCUs or mg chymosin? Or just trying to figure out if your rennet is "good enough"

That procedure you described is so inexact, it's hard to use it to gauge anything but extreme fluctuations in viability. Based on the procedure, your rennet is viable, and maybe getting a little old.

[tananaBrian]

What exactly are you trying to figure out? The strength of your rennet in quantifiable IMCUs or mg chymosin? Or just trying to figure out if your rennet is "good enough"

That procedure you described is so inexact, it's hard to use it to gauge anything but extreme fluctuations in viability. Based on the procedure, your rennet is viable, and maybe getting a little old.

Right off the bat you're way over MY head  ...I'm very new to all of this  .  And being very new at all of this, my main quest right now is to find a milk type/source here where I live (Anchorage, Alaska region) that works for making cheese.  At this point, I'm not even sure if I can make cheese here with the milk that's available ...short of having to buy a cow share and a home pasteurizer that is.   2 of 3 mozzarella attempts have failed, possibly both my fault, possibly both at least partially due to the milk.  In the recipes that I've tried so far, the curding has taken longer than expected and by testing the rennet, I hoped to at least rule out that factor ...I haven't got a pH meter yet and pH strips (litmus paper) seem to be a tough way to measure pH very accurately.  As far as I know, the best way to test milk suppliers is to curd the milk and then examine the curd ...firm, mushy, looks like cottage cheese, how long did it take etc.  I assumed that Ricki Carroll's method of testing rennet should at least get me in the ballpark, no?  I'm very open to advice!

Brian

[linuxboy]

Ah, got it, you just want a straight answer. Based on what you did, the rennet you have is somewhat weaker than single strength. Use about 1.3-1.5x the rennet amount called for in recipes, and it should give you a reasonably good set.

I suggest you start with easier cheeses such as halloumi, queso blanco, and panir, before moving on to a cheese that is very dependent on milk quality and acid levels, like mozzarella.

[tananaBrian]

Ah, got it, you just want a straight answer. Based on what you did, the rennet you have is somewhat weaker than single strength. Use about 1.3-1.5x the rennet amount called for in recipes, and it should give you a reasonably good set.

I suggest you start with easier cheeses such as halloumi, queso blanco, and panir, before moving on to a cheese that is very dependent on milk quality and acid levels, like mozzarella.

I'll take your advice ...and thanks!  The moz was mostly because I tried it and failed, and I have a hard time walking away from something that didn't work ...if anything, it makes me hard headed and determined to stick with it until it works!  BUT, sigh, I'll take a short breather and make some other easier cheeses before trying the moz again.... and will keep reading/thinking in the mean time.  I just got $100 in a birthday card ...hmmmmm, I see a pH meter in my future!

Brian

[MrsKK]

Just keep that enthusiam up!  You've chosen a tough cheese to master as your first, though.

[tananaBrian]

Just keep that enthusiam up!  You've chosen a tough cheese to master as your first, though.

Everyone here has been very encouraging, something I find to be common in the 'artisan' world ...I also frequent The Fresh Loaf and the people there are much the same.

I'm going to look through my books and decide on some simpler cheeses to make, although I can't say that I'm a big fan of the 'plain white' cheeses like paneer ...I mean that I like them, but they don't excite like a good Gouda or Stiltons (my Holy Grail goal is a good blue stiltons).  I'll see what I can find, and in the mean time, I'll test a bit more milk. 

thx,
Brian

[MrsKK]

Colby would be my suggestion for a cheese for you to try.  I find it to be delicious as a young(er) cheese - 6 to 8 weeks - and is less fussy to make than cheddar, for instance.  It is a cultured cheese, but you can use storebought buttermilk for your culture if you don't want to buy anything.

[tananaBrian]

Colby sounds good ...but due to holiday and work schedules, I won't get to try until after the New Years    In the mean time, I'll test and compare a few different local milks to see how they curd compared to each other.  I'm an engineer ...I like experiments.  I'm going to order a pH meter after the end of the year too (so I'll be here to receive it).

Thanks!
Brian