Shrink and water activity comparison (Aw)

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Shrink and water activity comparison (Aw)

Post by Butterbean » Fri Apr 15, 2016 20:20

Am not a meat scientist so please bare this in mind when you read this but I have been trying to get my head around water activity and meat shrink an charted this relationship and thought someone might find this informative. Granted, there are many factors influencing the binding of water but I thought this still might be useful to someone and worth sharing.

Process used Marianski`s Soppressata recipe on page 505 in his Home Production of Quality Meats and Sausages. Adjustments to recipe were the use of 14% back fat rather than the 20% and a FRM-52 as a starter. Beginning meat pH was 5.6. Course ground and stuffed tight in 32-35 hog casings.

4-1 p.m Pulled links out of fermentation chamber. pH 4.86 Put in smokehouse and cold smoked using cherry.
4-2 a.m Stopped smoke and left to hang.
4-6 p.m 17.44% shrink aW= 0.96 Noticeable color formation
4-7 p.m 24.4% shrink aW= 0.94
4-8 a.m 28.1% shrink aW= 0.94 Firming up
4-8 p.m 29.8% shrink aW= 0.91 Angel tears beginning to form.
4-9 pm 32.1% shrink aW= 0.91 Color peaked
4-10 a.m 35.6% shrink aW 0.90
4-11 a.m 38.6% shrink aW = 0.87
4-12 p.m 39.7% shrink aW= 0.88 (note - raining heavily)
4-13 p.m 41.2% shrink aW= 0.86
4-15 a.m 42.3% shrink aW = 0.83

Hope this is helpful to someone.

At 42.3% shrink.

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Last edited by Butterbean on Wed Jan 10, 2018 14:26, edited 1 time in total.
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Post by Bob K » Fri Apr 15, 2016 23:15

Great info BB! what is really remarkable is the .91 Aw value at a 30% weight loss. Spot on for what Marianski recommends for a target shrinkage. Great looking soppressata! I have never tried it smoked.
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Post by ped » Sat Apr 16, 2016 08:16

How did you check Aw BB ?
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Post by Butterbean » Sat Apr 16, 2016 15:04

ped wrote:How did you check Aw BB ?
I used a Decagon Pawkit.
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Post by Butterbean » Sun Apr 17, 2016 16:25

Thanks Bob, everyone seems to like his recipe. I prefer to smoke to keep the mold at bay. While I understand the benefit of mold on the slow cured salami I don`t see the need in faster fermentations and actually find its presence problematic because when I cryovac the mold turns ugly and I don`t like the thought of pulling the casings off each stick before packaging. By omitting mold, I can go straight in the bag and once sealed the casing comes off easy when opened and it looks much more appetizing. Using cherry, the smoke is hardly noticeable when fully dried but it does smell wonderful when it first begins the drying cycle but fades about half way through.

You noted the aW of 0.91 and the 30% shrink. Its pretty neat how we can use science to prove the old methods were right. I had suspected this but I had to know. Like everything else in this craft there are a lot of variables we need to understand and while it is safe at this point its actually safe sooner since the pH and the aW both play a part. The most concise guide I found relating to this is from the Agricultural Utilization Research Institute (AURI) where they give the following guide:

Its stable when:

*** pH of less than 5.0 or
*** Water activity of less than 0.91; or
*** pH of less than 5.2 and a water activity of less than 0.95

Looking at my time line you can see it became stable sometime between 4-6 and 4-7 when the shrink hit 20% which incidentally is the shrink used for semi-cured sausages. I also thought it interesting this was also the time when the rosy color first became obvious. When it bloomed.

With all this in mind I wanted to see how all of this effected our main pathogens. Here is some more info on this I thought helpful in getting my head around how our safety hurdles come into play.

Microorganism Water Activity Growth Limit Value Based on aW only.

Escherichia coli 0.95
Salmonella spp. 0.95
Listeria monoctyogenes 0.92
Stahphylococcus aureus 0.88


As a disclaimer, I would like to say there are a lot of variables that affect all of this as well as some conflicts in numbers and I am far from understanding all this but in general I think if someone used common sense they could use this example to give themselves a better understanding of what is going on with their salami as it is created. For me, it`s reassuring to see things become stable much sooner than I once thought - at least for fast fermented sausages where pH plays a major role. As for the slower fermented sausages it seems things are a bit more complicated and it took more understanding on my part to prove to myself but I succeeded but I won`t bore you with that "book". I think I`ve said enough. :oops:

I may just be a simpleton, but I just find this whole subject interesting and think it cool to be able to smell the aromas, watch the bloom and see the angel tears and understand what these signs mean. I believe when someone understands what these aromas and signs indicate they will be sharing the art of our ancestors.
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Post by Bob K » Sun Apr 17, 2016 16:37

By angel tears do you mean the fat/oil droplets that appear when sliced?
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Post by Butterbean » Sun Apr 17, 2016 18:21

Before slicing they appear. The angel tears are the little drops of liquid fat that first begin to appear usually at ends of the salami but they can be anywhere. I think its less pronounced on molded salami - last molded salami I did just showed wet spots or streaks. I think it comes from the compression of the soft fat but I don't know.

My good friend is Italian and he shared this term with me and its what they use to signal the soppressata is done. He knows nothing about the why's of salami making he was just taught and its a term his aunt taught him. She's Calabrian(sp?) and the one who said you add wine "for the bugs."

You can see the tear at the end of this sausage. Neither of us mold soppressata and we both prick heavily so I think the oil probably comes from a pin prick.

Image

He and I were talking yesterday and I was telling him how another friend is going to give me a whole pig to make soppressata with. He was telling me to keep the hams separate and just use the ham meat only for for this. He said that was how his family did it and it made for a much better product. I don't know about this but there is no arguing with him. I've asked for his recipe but apparently there is none. Its all done by handfuls and estimation but I've eaten it and its pretty good but I prefer Marianski's recipe but I'm not about to tell him that. :lol:
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Post by Bob K » Mon Apr 18, 2016 18:30

While I really hadn't noticed the tears on salamis I had drying for 2-3 months, unless they were sliced, I had made some sopprassata back in december and they got stuffed into what turned out to be 65mm+ middles. I pulled some after 90 days and it was fine but a bit softer than I prefer. I left a few chubs hanging. They started to develop brown spots and I thought they were goners. Cut into one and its the best I ever had, turned out the oil discolored the white mold and all was still fine, in fact it really cried upon slicing. Other one is still hanging.
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Post by harleykids » Mon Apr 18, 2016 21:15

BB,

Do you cold smoke all your salumi?

And as far as keeping the mold off, from the looks of your pics above, it looks pretty much 100% mold free?

I have been thinking about how to make my future salumi mold-less (sorbate, etc) and it looks like cold smoking may be the best way to do that with minimal fuss?

I don't want all my salumi to have a smoke flavor, however faint, but you say it goes away about 1/2 way thru the chamber drying process?

How long do you cold smoke to achieve the "mold barrier"? Just curious!

And I assume you ferment all your salumi as normal (24-72 hours, or until target PH drop has been achieved) and then cold smoke before putting them in the drying chamber to dry?

I may try to get a small dorm fridge to do my cold smoking in. This way I can cold smoke through the upcoming Summer months while maintaing the temp in the 40's-50's.

I would just modify the dorm fridge to accept a heatless smoke generator...cold fridge plus as long a smoke as I wanted to do.

Any advice?

I, too, perfer the casing to stay on the salumi, and for the salumi to be mold-free.
Sounds like cold smoking may be a convenient way to do this, while not adding an overpowing "smoked" flavor to the salumi?

Thanks!
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Post by Butterbean » Mon Apr 18, 2016 21:57

Bob K wrote:While I really hadn't noticed the tears on salamis I had drying for 2-3 months, unless they were sliced, I had made some sopprassata back in december and they got stuffed into what turned out to be 65mm+ middles. I pulled some after 90 days and it was fine but a bit softer than I prefer. I left a few chubs hanging. They started to develop brown spots and I thought they were goners. Cut into one and its the best I ever had, turned out the oil discolored the white mold and all was still fine, in fact it really cried upon slicing. Other one is still hanging.
I think what you were noticing were the angel tears. They are not as pronounced with mold because the mold seems to act like a sponge.

Here is a picture of angel tears on molded salami. It pretty obvious on the third row from the left but you can see them on the larger salami further to the right as well. Bob, is this kindof what it looked like?

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Post by Bob K » Mon Apr 18, 2016 22:20

Easiest way to explain! I will take a pic when I cut it next month. A few months ago it was pure white

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Post by Bob K » Mon Apr 18, 2016 22:28

Jason -
Note BB's time frame (two weeks) and type of culture, also the casing size and type.
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Post by Butterbean » Mon Apr 18, 2016 22:59

Bob, that looks like what I was seeing on the molded salami. What was the shrink when the photo was taken?
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Post by Butterbean » Mon Apr 18, 2016 23:55

Jason, I cold smoke most but still use the mold on some. More frequent with the larger casings and the slow fermented salami.
And I assume you ferment all your salumi as normal (24-72 hours, or until target PH drop has been achieved) and then cold smoke before putting them in the drying chamber to dry?

Yes, I do that but I no longer use a drying chamber but I will only make salami about 8 months of the year. Once I take them out of the fermentation chamber they either get hung in the kitchen or they go in the smokehouse. I'll cold smoke for a day then just leave them in the smokehouse till I need the smokehouse and at this point I just hang the from the ceiling.
And as far as keeping the mold off, from the looks of your pics above, it looks pretty much 100% mold free?
It pretty much is mold free and I have a very heavy mold population. I have it growing everywhere. I opened a package of shredded cheese Saturday and noticed there was white mold growing on it today.

But I packaged some salami today that was about as dry as I dared take it and there was no mold on it whatsoever but nature is a funny thing and I don't think there are absolutes. I have seen mold grow on smoked salami I had forgotten about. It had hung for several months though. But in general, if you give it a good smoke for a day I doubt you will see any mold.

Sounds like cold smoking may be a convenient way to do this, while not adding an overpowing "smoked" flavor to the salumi?
I find it very convenient. As for the smoke flavor, I think you can adjust the type wood you use. This last batch I smoked I used cherry. To me, it seems milder than pecan. I also put together a package to ship to a guy who is walking the Appalachian Trail. In this, I had some of the smoked soppressata I packaged young - ~30% shrink. I sampled a pack before shipping it and it did have a smokey aroma but the the one's I dried further (42% shrink) had no smoke on them that I could notice. But I imagine someone with real keen senses might be able to pick up on the smoke but I can't. To me, while these two were the same they tasted totally different and I've asked him to give me feedback on which he liked best. Funny how you can change one little thing and come up with something tasting totally different isn't it?
I would just modify the dorm fridge to accept a heatless smoke generator...cold fridge plus as long a smoke as I wanted to do.

Any advice?
That would work but if you don't already have a fridge I have something in mind that you might find better.

What I have in mind is a modification of what Alan recently built. If you don't mind, check with him and get his review of his and if it sounds like something you'd want I'll give you the details of the modification I was going to suggest that he make to his if the bug catches him. Like a drug dealer I have to get him hooked first. :wink:
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Post by Kunde » Tue Apr 19, 2016 00:39

Nobody have tested to use liquid smoke?
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