How important is the right acidity/pH?

[Drentse Koster]

First post - thanks for any input.

I have made two batches of dried sausages with following recipe (converted to 1 kg meat):

750 lean pork (cured with salt+cure, stored for 48 hours in fridge, and afterwards: minced)
18 g salt (In first trial: 23g)
2g Cure #2 (in first trial: 2.5g)
250 back fat (small cubes)
Some natural yogurt
2.5 g dextrose
Spices (black pepper, pimento, nutmeg, etc.)

Only adaptation in second trial was reducing salt: first batch was tasty, but excessively salty.

I hung them for 3 days at 65 ºF (18 ºC) and ~90% RH, subsequently cold smoked them overnight at about the same temp and RH. At that point, they lost 11% weight. I also measured pH, which came out in the 5.8-6 range.

I dried them at 60 ºF (16 ºC) for another week, and ~75% RH. At that point, I weighed them again. From an initial weight of little more than 1 kg, they lost 42%. They look and smell tasty. But when testing the pH, it reads about 5.8/6.

My main questions are about PH: literature tells that PH should be below 5.3, but obviously, it is not. I think my measurement is accurate - in earlier experiments with semidry sausage I did measure 4.9, for example, as I expected.

Can anybody weigh in on:
-The relatively risk of eating these sausages? Considering they are very dry now.
-The reason the pH did not drop more significantly? Is it temp? Do I need more sugar. (In earlier trials with other recipes, I also used natural yogurt, but with 10g sugar and at 70C)

[NCPaul]

Welcome to the forum. Think of dry cured sausages as a series of safety hurdles; clean, good quality meat that has not come in contact with a lot of surfaces, the proper amount of Cure # 2, the proper amount of salt, lowering pH, and uniform drying to reach a low water activity. Personally I would not have reduced the Cure #2 between the first and second trials (I can't see where you are located, so I'm not sure of your Cure 2 composition). I might have gone down slightly on the salt but not as far as you did; I use 2.3 total NaCl as my bottom quantity. Do you have any meat cultures available to you? They are more reliable than yogurt and do more than just acidify. The last point is how quickly these dried, were they in small diameter casings?

[Drentse Koster]

Ok I will keep that bottom limit - 2.3 total NaCL - as my bottom limit for the coming trials. You mean weight percentage to the total sausage, right?

(Does the cubed back fat absorb much salt? Because if not, then my second recipe is 2.5 NaCl? Or is this too creative book-keeping?)

I don't have meat cultures: would that help - also with acidifying in the 65F range? I would really like to ferment at 65 F, which is room temperature in my house. If my next trial fails again at reaching low enough pH levels, I consider increasing temp but it will be a hassle.

Incidentally, I was also very surprised about the quick drying. They are in hog casings, stuffed quite full. Another trial, in parallel with the first trial, where I ran the back-fat through the Porkert instead of using a knife to cube it, dried much much slower. It seems that spreading fat over the entire sausage prevents fast drying, while concentrating it in cubes promotes fast drying.

Finally: what do you think about the reason that I didn't make the 5.3 pH level?

[NCPaul]

I set the meat and fat at 1 Kg. Together they are sometimes referred to as the meat block. I ferment my salamis in my over with a large tray of hot water. I put a sign over the control panel to keep my wife from turning it on. The oven is well insulated and holds the humidity high during the fermentation; if the salamis lose water too quickly, the bacteria won't have a chance to lower the pH. If the oven fermentation chamber grows cool, add fresh hot water or turn on the oven light for a while. The pH drop will be proportional to the amount of food you provide to the bacteria. I typically use SafePro F-LC and a minimum of 0.3 % dextrose. Because you are using yogurt, I can't give you any guidance on the amount of dextrose to use. Another option might be to acidify directly with lactic, citric or ascorbic acid (or GDL which is harder to find).

[wheels]

NCPaul is far more expert than me on pH. However, given that those pH figures would be expected shortly after slaughter, rather than days later, are you confident of the accuracy of the pH tests?

Phil

[Drentse Koster]

So I increased the temperature to 75 F in the next trial, which gave me the right acidity (5.2) on the next trial. @NCPaul thanks for the oven tip.

So apparently, yogurt doesn't acidify well at 65F (=18C), even in moist conditions and with dextrose added. A temp of 75 (or similar) is needed.

Are there any started cultures you would recommend that can acidify reliably at 65 fahrenheit?

[wheels]

If you PM me your email, I'll send you the Chr Hansen brochure with details of all their cultures.

Phil