This video on how Gorgonzola is made makes the rounds pretty regularly. When I was first learning to make cheese, I found a lot of these videos interesting but kind of confusing–there’s a lot that goes unexplained. So here’s a thread of annotations!

Here the narrator talks abt where the cheese “can be made”. It’s not that it literally, physically, can’t be made elsewhere, but the name “Gorgonzola” is protected under EU and Italian law, rather like “champagne”…

The EU Protected Designation of Origin (PDO, or DOP in Italian) and the national level DOC are extremely valuable certifications. In many cases the rules specify not only where the product can come from, but also the species of plant or animal that must be used in its production and sometimes, how it’s made.

The species & breed designations have been extremely important in protecting the economic viability of heritage breeds: because the PDO designation allows producers to market and charge for premium products, they can afford to use traditional breeds that may not be as high yielding as the workhorse breeds used by mass-market producers, but have unique characteristics that make them better suited to being raised sustainably in their traditional regions: they require less water for example, or they tolerate cold or heat especially well and can spend most of their time outdoors, or they’ve developed a resistance to local diseases and pests. Tl;dr the PDO scheme and earlier national ones play a significant role in preserving biodiversity in both plants, like wine grapes, as well as livestock.

The specifications about how a product can be made primarily protect the producer economically–it means that they don’t have to find endless ways to speed up their processes in order to stay profitable. But that economic support for slower production turns out to be meaningful on a microbiology level for fermented products like cheese. By allowing the microbes to do a slow, thorough job of working through the curd, we consumers get a greater range of flavors–which are the byproducts of the metabolization of fats & proteins–and also fewer of the proteins that can be inflammatory for some people are intact enough to cause problems. And for everyone, our own guts have to do less of that same breaking down & metabolizing work.

At 1:09 we see a tool is called a trier. You’ll see it a bunch of times throughout the video. It allows the producer to check on the state of the interior of the cheese without disturbing the whole rind or exposing too much of the interior to new things.

After they look at the sample, they carefully fit it back into the tunnel they made, and then seal the cut mark on the rind (traditionally with a smear of the cheese) to prevent oxygen and ambient yeasts from further entering the interior.

This tool at 1:57 is called a cheese harp. Once the milk has coagulated into a gel, it’s used to cut the curd into squares in order to release the whey.

Americans are often weirded out by mold, but it’s absolutely part of the cheesemaking process, and its presence on the rind as the cheese ages is a big part of what flavors the cheese.

Producers will often brush off the ones that grow too tall, sometimes spot-treat any that they don’t want there. Big producers of long-aged pressed cheeses that normally have “natural rinds”–especially those selling to the American market–often slap a breathable film on their cheeses as it makes it easier to brush off “unsightly” molds and maintain even, pristine-looking rinds. But this is the opposite of how cheeses are normally aged, and it comes at the expense of complex flavor.

Here at 2:28 you can see a sort of plastic girdle around the center of the cheese. This isn’t something that’s used on every type of cheese. It’s just that these cheeses are both tall and very soft, and the girdle helps it stand up straight and maintain its shape during the aging process.

The same sort of thing is used on Vacherin Mont d’Or, a very soft, gooey cheese from the French Alps. I used spruce versions for aging my Spruce Button cheeses.

Here's the spruce girdle. It's made from the inner bark of spruce trees, which is a whole craft and profession of its own pic.twitter.com/eLT66G5GyL

— IntoTheCurdverse (@curdverse) March 17, 2022

At 2:51 they talk about the 2 different kinds of gorgonzola, the softer “dolce” and firmer “picante”. They start out the same, but one is aged longer. They don’t say in the video which is older, but it’s the picante version.

This is true for most cheeses: they dry out as they age and that intensifies the flavors. The exception are surface-ripened cheeses like bries and other bloomy rinds, where yeasts & molds work their way into the interior of the cheese, eating through the protein structures as they go.

At 3:32 they talk about penicillium roqueforti, the blue mold, being added to the milk along with the other starter cultures. P. roqueforti is the most common strain used in blue cheeses, but its cousin P. glaucum is used in some blues instead such as Bleu d’Auvergne and, in fact, some gorgonzolas. Glaucum is more of a grey-blue and has a slightly milder flavor than roqueforti.

But these are just 2 of many, many blue strains that exist in the wild, and there are numerous substrains within each of those. These are the ones that people decided they liked and isolated so as to ensure consistency in cheesemaking. The blue mold that grows on the bread you keep in a plastic bag may be one of these, or it may be a slightly different one. If I let my aging cave get too moist, I risk having it get colonized by my local blue mold–which is a purple-blue, and has an acrid peppermint flavor which can permeate a cheese even if it only gets on the rind.

The section from 3:37-3:42 is kind of confusing, because they just jump from adding starter cultures & rennet to liquid milk, and then cutting the coagulated curd, and it’s not obvious that time has passed. But at a later point they say it’s abt 20 mins.

At 3:45 we see the curd harp again. The worker does one cut, then walks 90 degrees around the pot to cut again, forming a checkboard of cuts so that there are evenly cut squares of curd throughout the vat.

20 mins is not long at all, and as you can see at 3:52, the curd is extremely soft and delicate. If you watch other videos about harder cheeses, you’ll see the curds are often smaller, but also much firmer and easier to pick up.

At 4:02 you see the workers scooping the curds up w/bowls and pouring them, whey and all, into the molds. Because these curds are so soft, they naturally slip together and close up open space left as the whey drains out the bottom.

At 4:30, the cheeses are left to drain overnight. People often assume these means they’re refrigerated, but that won’t happen for several days. The starter cultures need fairly warm temps–75-90F usually–in order to work on consuming the lactose in the milk and convert it to acid.

Acid means flavor. If you’ve ever had a really bland cheese, that’s a cheese where acid production is stopped at an early stage in the cheese making process. The salting shown at 4:34 is the point where that acidification is stopped the next day.

Stopped on the rind, in any case. There’s still stuff going on inside the cheese. There’s still lots of whey in the curd at this point, and the cheeses will continue to shed whey for several more days. The salt on the rind helps draw it out.

Whey flows faster at higher temps, which is why the cheeses then spend a few days in a “warm” room (usually in the 60s F). The picante versions spend more time there both to draw out more whey, and to give the mold spores more oppty to grow aggressively.

Puncturing: not all blue cheeses are punctured, but most are–and it’s pretty unique to blue cheeses. The holes in the rind are there to allow the blue mold spores access to oxygen as they’re starting to sprout.

These are still very young cheeses, though. The curd and rind are soft and still actively trying to knit together. So just like a cut on your skin, the holes will close up pretty quickly as the cheese ages. But by that time the mold spores will have gotten going. Because the cheese wasn’t pressed and the curds just kind of found their own places as they were placed in the molds, there are actually a lot of little open seams within the cheese, which allows the mold spores to effectively send out runners and spread thru the cheese. By the way, Cheesescience.org is a great resource for all the microbial details of cheesemaking for the Average Joe. He has a good article on the doings of P. roqueforti inside a cheese.

Finally, at 7:34, they talk about the foil wrapping. But in the video they mostly talk about it in terms of displaying the DOP designation I talked about earlier.

But there’s a reason it’s foil, and not some other type of wrapping: blue molds are REALLY aggressive. They will happily colonize anything given the chance. Many cheeses are wrapped in special papers or plastic films (think of that white paper around your Camembert) that allow the cheese to breathe as it’s transported from the manufacturer to a store.

But no retailer wants the blues colonizing the rest of their cheese case, and you don’t want them doing that to everything else in your fridge. So, just as tinfoil hats are good for keeping your thoughts from getting out to Them (whomever you’re afraid of), foil is used to keep your blues contained. /fin

Originally tweeted by IntoTheCurdverse (@curdverse) on March 19, 2022.