Late Blowing or Early? Also... To much acid development?

[Tedybar]

On November 12 I made my first Gruyere.  I used 12 quarts of raw milk (which is from a licensed dairy, which means they have to do stringent checks on their milk to make sure it is not contaminated and is safe for human consumption) and 4 quarts of pasteurized skim milk.  I used a 1/4 tsp Biena (Abiasa) Thermophile Type B and a 1/4 tsp Biena (Abiasa) Thermophile Type C, and no other cultures.  After about two weeks of aging, I waxed the cheese.  About 5 weeks after making the cheese, I noticed the cheese had cracked the wax and you could tell by the feel that there was a lot of gas production going on.  My cheese fridge temp stays between 50 - 54 degrees F.  I was just going to patch up the wax, but on closer inspection I noticed the cheese rind itself was cracking.  I decided since the rind was cracked, I would be better off vac packing the cheese instead of waxing over the cracks.  I removed the wax and cut my wheel of cheese in half.  As you can see in the attached picture, there was a lot of gas production going on.  I was going for a Swiss style gruyere, and did not add anything that would have caused the gas production.  The holes do seem shiny, and due to the time it took for the issue to show up, I was assuming this was late blowing.  Does this sound like a good assumption?

Also, although I didn't taste it, I did smell the cheese.  It smells "cheddery".  I have since purchased a Baby Swiss from the dairy I get my milk from and it also has a slight "cheddery" taste.  Tonight I cracked open my first and only so far, Vacherin Fribourgeois.  Once again it had a slight "cheddery" taste.  It was also a bit sour & a bit grainy.  I brined this based on the brine times in Mastering Artisan Cheesemaking, but I do know I can struggle with the timing during the cooking stage... My curd tends to be ready to quickly.  I know for my last Gruyere, made last week, I applied what I just read in Mastering Artisan Cheesemaking about removing some of the whey if this happens and replacing it with water.  It has only been a week so I do not know how that will turn out yet.  So right now, I am thinking my issues are acid development while cooking the curd, and possibly the influence of some native mesophiles in the milk?

[B e n]

I can't help with the late blowing part, but on the cooking part, you mentioned struggling a bit. The recipe gives the following instructions:

Cut curd mass into 1/4" cubes, let rest in pot for 5 minutes, cut into 1/8" cubes. What was your level of success with this part, uniformity, size, etc?

Stir and heat:: Stir gently and increase temp slowly to 118-120°f over 1 hour, pH target 6.35. What was your heating technique, and did it take the full hour to hit the temp goals? Did you check the pH? If not, what did it taste like at this point?

Drain and texture: Did you keep the curd mass under the whey in this step?

[Aris]

Sounds like late blowing which happens weeks after making the cheese. It might be the pasteurized skim milk that caused the late blowing. Is your raw milk grass fed? and what is the temperature of the brine? It is good practice to brine cheese at 50-55 f.

[Tedybar]

Cut curd mass into 1/4" cubes, let rest in pot for 5 minutes, cut into 1/8" cubes. What was your level of success with this part, uniformity, size, etc?

I just go with the balloon whisk cutting method.  I plunge the whisk into the curd until the entire surface shows cutting, then let it rest, then do a final cutting with the whisk.

Stir and heat:: Stir gently and increase temp slowly to 118-120°f over 1 hour, pH target 6.35. What was your heating technique, and did it take the full hour to hit the temp goals? Did you check the pH? If not, what did it taste like at this point?

I use a Sous Vide in a water bath.  I do not have any way to test pH, but I use the method of getting a bunch of curd in my hand and squeezing, then breaking it apart to test curd readiness.  I takes me a full hour to hit the temp goals, or maybe a little longer, but the curd tends to be ready prior to the hour.  I try not to over stir, usually giving a stir every minute or so...  I have never tried tasting the curd in this step.

Drain and texture: Did you keep the curd mass under the whey in this step?

I'm not 100% sure what you are referring to here... I let the curd settle under the whey before draining, but the curd cannot stay under the whey once drained...

[Tedybar]

Sounds like late blowing which happens weeks after making the cheese. It might be the pasteurized skim milk that caused the late blowing. Is your raw milk grass fed? and what is the temperature of the brine? It is good practice to brine cheese at 50-55 f.

Yes, my raw milk is grass fed.  I keep my brine in my cheese cave, so it is generally at the 50 - 55 f range.  That said, the container I was brining in did not fit in my cheese fridge, so I put it in the regular fridge for brining.

[Aris]

Sounds like late blowing which happens weeks after making the cheese. It might be the pasteurized skim milk that caused the late blowing. Is your raw milk grass fed? and what is the temperature of the brine? It is good practice to brine cheese at 50-55 f.

Yes, my raw milk is grass fed.  I keep my brine in my cheese cave, so it is generally at the 50 - 55 f range.  That said, the container I was brining in did not fit in my cheese fridge, so I put it in the regular fridge for brining.

The cheese having the right salt content can prevent late blowing. Salt absorption will be slower when brining at cooler temperatures from what I've read so it is possible your cheese is under salted which caused late blowing. Another factor is the pasteurized skim milk. 

https://fil-idf.org/wp-content/uploads/2017/03/Factsheet-001_2017-The-importance-of-salt-in-the-manufacturing-and-ripening-of-cheese.pdf

[Bantams]

I don't see a photo, but it sounds typical of Clostridium/late blowing.  Probably more likely this time of year if farmers are feeding silage (main contributing factor). Clostridium is not included in state milk testing.
If wanting to make Alpine type cheeses from raw milk, find a source that doesn't feed silage/haylage. 
And just for future reference, PA raw dairies have 2 samples rested per month and the bacterial/SCC thresholds are quite high.  So it doesn't really mean much.

[Tedybar]

For some reason I cannot attach a picture.  I tried, but I keep getting told there is an error and it cannot post.  Although I did just think I can do a link to Google Photos: https://photos.app.goo.gl/vv68HfLdKmvNgUav7

The farm I get my milk from only uses pasture and dry hay for feeding their cows.  No silage.

[Bantams]

Ah, that helps! Those are just mechanical openings(coliform and Clostridium makes round bubbles). 
Next time gather the curds into a mass under the whey, and then transfer to the mold, which is ideally under whey to begin. 
It's definitely an art and requires practice.  I found it immensely helpful to watch videos of Alpine cheese makers scooping their curds and filling molds. 

[Aris]

The cheese looks like it has late blowing defect for me. The holes are too numerous and there are big crevices.

[Tedybar]

Thanks for that article on salt, Aris.  It was very interesting and informative.  I will be trying to work out a way brine in the 50 -55 F range in the future.  I will also give up on trying to cut cost by supplementing my raw milk with regular store bought skim.  I will go full fat or skim the milk myself.  I am just stubborn enough to keep this up until I have this mastered...

[Bantams]

Looking again and rereading your original description, I think it could still be Clostridium. It can be a bit tricky to tell from one photo.