Friday, September 2, 2016

Making ham (and bacon)

Making (city) ham


City ham is wet cured in a brine for about a week, then heated for final processing (either sous vide or smoking). It's different than country ham, which is salted and then hung for months while it gradually loses weight.   The spiral cut honey ham or the ham on your ham and cheese sandwich is a city ham.  Proscuitto or Jamon Serrano are country hams.  Sally and I had a great rosemary ham at Industrial Eats in Buellton when we took a charcuterie class from Jake at Valley Piggery.



That's a nice piece of meat
Ham starts with the hind leg of a pig. A whole shank is 15-20 lbs, so I got just the shank end (that's the end closer to the foot, or trotter), about 8-9 lbs, conveniently boned out by the butcher.  The butt or sirloin end (closer to the hip) is more complex muscle wise, and harder to make a nice carveable piece of meat out of.
So here's my shank end, ready for the curing mix

I got my ham from Michael at Ventura Meat Company.  They have good pork from humanely raised pigs.


Starting the cure

City ham is cured in brine, and to make the curing more even, you inject the brine into the middle of the meat with a large syringe. Otherwise, the outer part of the ham would be very salty, and the middle not so salty.  The brine in this case was a mixture of brown sugar, salt, curing salt, rosemary and garlic.

The ham sits in the brine for a week. I put it in the refrigerator door, and every time you open or close the refrigerator, the brine swirls around so it stays nicely mixed.



It comes out of the cure

Just came out of the brine
After a week, you pull it out of the brine and rinse it a couple of times to reduce the saltiness of the surface.  If you've done it right, it has an even pinkish color from the curing salts. Yes, nitrites are your friend here, and so-called "uncured" bacon and ham uses celery juice which has a lot of nitrites in it.  With modern chemistry, we can control the amount of nitrite to just what's needed to prevent bacteria growth, but to minimize the formation of nitrosamines (if you fry or grill the ham).

You then need to let it sit for at least a day in the refrigerator to dry out. At this point, you have a decision - you can just heat it and use it, you can sous vide it, or you can smoke it. You could probably eat it at this point: the curing kills any bacteria, but it's kind of gelatinous and squishy (like raw meat, but tougher).  I decided to do the latter two, so I cut my cured ham in half.

After sitting for a week - check out that nice color and texture

Final steps

The first half, I vacuum packed, and put into the sous vide cooker at 65C.

Bagged and ready
Cooking at 65C


And this is the final product


 Smoking

The second half, I smoked at 180F to an internal temp of 145F.  I think it could have gone slightly higher.. the fat is still kind of gelatinous.  Maybe 150F would be better - it's not like the temperature calibration on the probes is all that good, so maybe it was lower than the sous vide, which is the perfect texture.

Smoked city ham

And, bacon too!


Bacon out of the smoker
I also got 5lbs of pork belly to make bacon out of.  I tried two different cures: a straight up maple sugar style, and a more complex molasses, juniper berry, and other seasonings.  Those sat in plastic bags in the refrigerator for a week, then got a few hours of apple wood smoke to 150F, and are ready to cook and eat.

Ready to eat!

Thursday, March 17, 2016

Shortened dipole for 40 meters


The question comes up on the tower talk mailing list about using a single 30m dipole (actually 15m long) for 40 meters with a matching network. Is the gain significantly less? Is the matching network a problem.  4nec2 answers these questions.  The models were lossless (for the antenna, not for the matching network), and modeled as 10 meter and 7.5 meter long dipoles fed in the center, with the element radius of 1 cm.

Full size is 2.08 dBi, Shorty is 1.75 dBi, mostly because of the slightly wider main lobe for the shortened antenna.


Here's the gains of the full size dipole vs the 75% length dipole (with the matching network):
Gain of 75% sized dipole for 40m
Gain of full size dipole for 40m



Now let's look at the impedance of the short antenna and the required matching network
Impedance of 75% dipole around 7 MHz:
Capacitive, about 30 ohms and -350j to -250j ohms
Impedance with the low pass T feed, tuned for 7.15MHz
4nec2 has a neat feature where it will calculate the values for a matching network.  I picked the low pass T, since I knew I'd need some significant series L to compensate the antenna's overall capacitive reactance.  An L network would also work, as would a tapped inductor.

So the series L (about 7.5 uH) compensates for the capacitive reactance (-300j) and brings the resonance to 7.15 MHz.  Here's the VSWR plot for the matched antenna.  Not too bad, the 2:1 bandwidth is about 350 kHz, the 1.5:1 BW is about 180 kHz.

Let's compare that to the VSWR of the original 40m antenna. which has a wider 2:1 bandwidth, 460 kHz, but a narrower 1.5: 1 BW of abotu 150 kHz (because the best match is only 1.4:1 due to the original antenna being a 72 ohm impedance)