Google Analytics

Tuesday, December 27, 2011

Home Security System - Part 4

Link to part 1
Link to previous page
Link to next page

Home Security System -Part 4

When using the magnets I bought at Radio Shack for testing, I found that:

  • The sun-room, which has 5 windows and 1 exterior door: all windows and the door were wired individually, with the 6 wires being pulled down to the security box.  None of the window nor the door have magnets in them; just the sensor in the frame.  So I'll have to drill a small hole to insert and glue some magnets (I bought some smaller ones from Staples at 6 for $3.00 that are smaller than the ones from Radio Shack).
  • The dining room, which has 2 windows, had a sensor on each window, but the test revealed that the wire from the left window never made it into the security box.  So I pulled the sensor up out of the window frame, cut the wire, and patched it into the wire for the sensor on the right window.  So now these two windows are daisy chained (series) wired together.  I tested this at the security box and they are good to go, but I'll have to add the missing magnets into the windows as noted above for the sun-room.
  • The living room has 2 windows, and they both tested OK, but are missing magnets, so they will get the same magnet install treatment.
  • The front door does not have a sensor on it.  I'm going to buy a simple door/window sensor.  I'll pull the wire from the nearby living room window and splice it into that wire, so the left window and the door will be on the same circuit (daisy chained) while the right window will be on its own circuit.  However, I'm thinking about putting a PIR detector in this area, so I may have all three (2 windows, 1 door) on one wire (daisy chained) and the other wire going to the PIR.
  • The den has two windows.  They are missing sensors.  The exterior door into the den does not have a sensor.  I'm thinking about pulling a wire from the closest sun-room window to the two den windows and the door, so they would all be on the same circuit together.  
At first I thought I would just ignore the door and window sensors and just go with PIR devices, but then I realized that, during the daytime when we are moving around downstairs, we would have to take the PIRs out of service to avoid alarming on our movements.  But I want to be able to alarm if someone is coming in, so that meant I needed to be able to take PIRs out of service while leaving the windows and exterior doors in service, so I need to get the windows and doors going.

I'm moving along pretty nicely.  Tomorrow I hope to drill and glue up the magnetic buttons over all of the sensors.

Also, during my 'Quick Hitter', I bought some fake exterior cameras.  I intend to install some real cameras, but I wanted more time to do some research before committing to a brand, so I bought these fake cameras.  I mounted 2 of them today.  They have a blinking red led on them, and are actual cases for actual cameras, so they look real enough.  It took about 10 mins to mount them.  I put them where they would be easily seen, as I'm wanting to deter someone from breaking in.  The 'video surveillance' signs should be coming soon...


Link to part 1
Link to previous page
Link to next page

Monday, December 26, 2011

Home Security System - Part 3

Link to part 1
Link to previous page
Link to next page

Home Security System - Part 3


Unable to find locally the little 'recessed security window magnetic reed switch' so I went to Radio Shack and bought some magnets, with the idea being that I will place the magnet on each of the sensors on the windows downstairs and then see if I get any continuity at the system box.

Update
I was able to buy 10 magnets at Radio Shack for about $6.00 for testing.

A brief note: Windows and doors typically use a simple sensor - it's typically a reed switch that can be closed (electrically like turning a light switch to 'on') by the presence of a magnet; removing the magnet causes the reed switch to 'open' (electrically like turning a light switch to 'off').

What I had observed on the windows was a little circular tab (the reed switch and wires) on the casement of the window sill, under the window pane itself.  There should have been a magnet installed on the wooden frame of the window pane, but the builder had not installed these.  Normally, opening the window by sliding the window pane up, with the magnet attached, would pull the magnet away from the reed switch and the circuit would be electrically open, which typically is the alarm function.

An installer has a choice when installing the sensors; they can 'daisy chain' the sensors together, so in the case (like ours) where we have 5 windows side-by-side (in the sun-room; the rest of house windows are also wired), the wire would go window-sensor to window-sensor, and after all 5 had been been joined, a single wire would be taken down the security box.  This would have meant that, if any one window, or any combination of windows including all windows, had been opened, then the circuit would be open.  This would mean there's no way to determine which window was opened, just that one or more of the windows on that daisy chain had been opened.  The benefit to this approach is (from your view) is that this constitutes a zone, and it will only take up one sensor slot on your security motherboard.   So, in this case where I have 5 windows, it would have taken up just one sensor slot on the security mother board.  And since they are all side-by-side windows, I don't care about which window might be in alarm, just interested in knowing that one of these windows - any one, is in alarm. So this would be a good area for a daisy chain, and a 'zone'.

Another way to wire this is to have each window have it's own individual wire go down to the security box.  This way, you know which individual window was opened.  But this means you would have to use 1 sensor slot per window sensor.  So you get more detailed information (which individual window is alarming), but at the cost of more slots used on your security motherboard.  As it turns out, my windows were individually wired this way; I was expecting daisy chain, but instead it was wired for each window to be sensed.  So all 5 wires were pulled to my security motherboard.

Since most security motherboards have a limited number of sensor-slots, it is usually the case that you won't want to sense the individual window.  For example, my DSC 1500/1550 motherboard only has 6 sensor slots total.  So, if I were to wire up each of my 5 windows to an individual slot on the security motherboard, then that would just leave me 1 more slot for the entire rest of the house!  Not what I want.

Note: For the following to be clear, we need to make a distinction between a wire.  In this case, when I'm referring to a wire, it's referring to the 2-conductor wire that goes from the window sensor to the security box.  Inside of this wire are 2 conductor wires, which I'll refer to as conductor 1 and conductor 2.  So a wire, in this case is what goes from the sensor to the security box, and this wire has 2 conductors.


So down at the security box, where all of my wires come in, I'm going to have to join each of the 5 wires from the window sensors into a daisy chain.  This means I will take, starting with the first window sensor wire (each of these wires are a 2-conductor wire), I will take one of the conductors and join it with one conductor from the second window sensor wire.  So I'm joining a conductor from wire 1 to a conduct from wire 2.  Then from this 2nd sensor wire, I will take the second conductor and join it with a conductor from wire 3.  So at this point, I've got 3 sensors daisy chained together: wire 1 conductor 1 is joined to wire 2 conductor 1, and wire 2 conductor 2 is joined to wire 3 conductor 1.  I will join wire 4 to wire 3 in this manner, and wire 5 to wire 4 in this manner.  When I am finished, I will have 1 conductor from wire 1, and 1 conductor from wire 5, left over; these are the beginning and the end of the daisy chain.  These 2 wires are the ones that will be connected to the sensor slot on the security motherboard, and will allow the security mother board to detect any window opening in the daisy chain on that slot.

This will occupy 1 slot on my security motherboard.

Since my system only has 6 slots total available, I've used up 1 slot, or 1/6, or 16.6% of my available slots just on the windows in the sun room.  So, I may decide to add some other windows that are close by to this zone.  For instance, the sun room has a door to the outside porch.  Since it's in the same area as the windows, I may decide that I don't care about being able to differentiate between this door and those windows being open, in which case I'll add the door to the daisy chain at the security box.  However, if I want the door separate, than I won't want to add this door to the daisy chain, and would add it to it's own individual slot.

So the determination I'm faced with: a) I have 6 sensor slots total, and I have a lot of windows, and a lot of doors in this house, which means some windows are going to have to be daisy chained, and maybe some doors.  b) I want to, at least, know that a certain area of the house has gone into alarm, rather than the whole house just being a jumbled up mess - I would like to know the area that is in alarm.  So I will probably daisy chain the sensors in a common area together.  This means I will probably join the sun room windows sensors with the sun room exterior door, along with two other close by windows in the den; this would mean I have 7 windows and 1 door joined together.  This is the approach I'm going to have to take throughout the house in able to be able to detect with just 6 slots.


Link to part 1
Link to previous page
Link to next page

Home Security System - Part 2

Link to part 1
Link to next page

Home Security System - Part 2
So, now I find us, 16 years later (today is Dec 26, 2011, and I'm retired), without a Burglar Alarm or Security System, and home invasions are taking place.  There have been 2 in the last 6 months in our area, one of which was about a mile from our home, and another about 2 miles from our home.  They appear to be deliberately waiting until the family is home before breaking in - 5 men breaking in around dinner time or early evening, tieing up the family, then ransacking the home for 3 hours.

So we're on edge about this, and I want to get our Security System online.

I gave this some thought, coming up with a plan:

  • My immediate goal is to get a Quick Hitter in place.  This may not solve all my desires, but it should give me some assistance with our security immediately.  It should make things better than they are without making anything any worse than it already is.
  • My next goal is to get our existing system online.  This could take some time to bring back to functional.  So it's divided into the following steps: 1) Examine existing system and determine whether to proceed with it or abandon it; 2) if proceed, then make it functional.
  • My final goal is to enhance our existing system (if possible) or add a new system.

Quick Hitter
  • Add external fake security cameras.  Since these aren't functional, they don't take long to install.  They may not stop all criminals, but they should give them pause for thought, and hopefully will deter some.  I can have all 6 installed in a day.  Ordered, waiting on delivery.
  • Add external 'video security surveillance' signs and place in prominent positions on the edge of the property.  Again, they won't stop all criminals, but should help and can't hurt. I can have all 6 installed in the same day I put the cameras up. Ordered, waiting on delivery.



Existing System
So I've spent the last couple of days determining the state of our system - it was left in the house but never finished.  Based upon that determination, I will:

  • Get the existing system functional and online and add additional capability.
  • Move on to a new system altogether.
The existing system is a DSC 1500/1550.  The thought of using the existing system has some appeal to me.  It appears that all of the doors and windows already have sensors installed, and the sensor wires pulled back to the system box.  In addition, there are two (2) keypads, located where we can work with the system, to acknowledge alerts, stop alarms, arm the system, and create an instant alarm.  So, since it's already there, I would like to utilize it.  In addition, there's an exterior siren already installed.  But this means a 'do it yourself' or DIY project.  It was missing the power supply, which I've ordered and received, along with a battery, which I haven't bought yet.

However, the existing system is in the current state:
  • There's just a bunch of wires in the system box.  They aren't labeled, and I don't know where they go.  In addition, there are different types of wires, which I would assume are doing different types of functions.  I counted 17 wires in the box.  These can be divided into 4 categories: 2 2-conductor round 18ga wires; 3 4-conductor 22 ga round wires (2 of which go to the keypads - don't know where the other goes, unless it was to the phone line which we don't have anymore - we're all cellular); 4 2-conductor flat wires (2 of which are brown, 2 of which are white - I suspect 1 or 2 of these are siren wires); and 11 2-conductor round 22 ga wires (which I suspect are sensor wires).  So I've got a bit of a problem here with all of the different wires, none of which are labeled.
  • I don't know if the system board is functional.
  • I don't know if the keypads are functional.
  • I don't know if the sensors are functional.
Existing System First Step

  1. Pulled all the wires out and categorized them (see above).  Done  Note: my system has no power going to it yet, so all the work I'm doing is to a powerless system at this point.  The last thing I want to do is power it up, and certainly not while I'm determining the state of everything!
  2. Pull the keypads out so I can get to the wiring.  Done
  3. Examine wiring to identify in system box: Done it's round 4 conductor 18 ga.  I have 3 of these in the box, but only 2 keypads, so 1 of those wires doesn't go to a keypad!  
  4. Identify which keypad goes to which wire in system box.  If there were only 2 wires and 2 keypads, then I wouldn't need to do this, but there are 3 wires, so I don't know which isn't a keypad.  Done  Did this by performing a continuity check and labeled in system box.
  5. Determine which sensor is associated with which wire, so I can identify the zones.  This means stripping off the insulation on each 2-conductor sensor wire and performing a continuity check.  It should read 'closed' or 'continuity' or very low resistance when the sensor is on a window or door that is closed.  Remember - this system wasn't supposed to be installed in our house, so who knows what work was done and what work was not done.  Bad news: all sensors are in open state!  That means: a) either the sensors are not connected to the wires, b)there aren't any magnets next to the sensors to make the sensors closed, c)the sensors have all failed in the open position.  In my opinion, C isn't viable, A isn't likely, so that leaves me with B as the most likely.  Sure enough, a quick examination of a window casing shows the sensor in place, but no magnet on the window itself.
Well, this is going to be a bit of a thorn.  Here's a rough look at a 'daisy chain' of 4 sensors that would constitute a 4 sensor zone, showing them all closed (non alarming).
___--____--____--____--____

Here's a rough look at that same 'daisy chain' of 4 sensors, with the 2nd sensor open (alarming), and the other 3 closed (non alarming).
___--____/ ____--____--____

Th 2nd sensor open (shown as __/  __) would stop the flow of electricity, the same as a light switch stopping the flow of electricity to a light bulb.  This one open sensor stops all of the flow.  Any of the sensors going open causes the flow to stop and the system to go to alarm.

Since usually the sensors in a zone are daisy chained together, this means for me to test my sensors, and I suspect all of my sensors are missing magnets, I have to somehow ensure all the sensors in a daisy chain have magnets to place into a closed state before I can test.  Since this is an abandoned project by the builder, I don't know what sensors are in a daisy chain together, and will be guessing at it at best.  If I'm wrong and I miss just one sensor in the daisy chain, then I will just see an open circuit at the system box.  In order to see a closed state, all sensors in the daisy chain have to have a magnet installed.  So that may be a bit of a problem, since I have no way of knowing which sensors in the house are on a single daisy chain.....but I'm going to try!

The first thing: get some magnets!

And that's where I'm at right now!

Home Security System - Part 1


Link to Part 2 of this article.

Home Security System Part 1
When we lived in Brandon, FL, we had a home security system, and kept it armed every single day.  That system was damaged when we had a lightning strike 50 feet from the house - it welded 'closed' all of the magnetic sensors throughout the whole house!  So, if you opened a window or door, with the sensor being welded closed, the open door or window could not be detected.  I turned in my claim to the insurance company and they paid me directly the fee quoted by a couple of security companies for repair.  Seems like it was about $1,600.  That was a lot of money looking straight at me, so I had a choice: pay some other people to affect the repairs; pocket the money and don't repair the system; pocket the money and repair the system myself.

I decided it was at least worth taking a look at to determine whether or not I could repair it myself, and it wouldn't cost me anything to look, nor would it increase the repair bill, so I took a look.  This was pre-internet days, so no access to information much during that time for things like this.

Each window had a small magnetic sensor that had been drilled and inserted into the window or door casing, while a magnet had been glued directly opposite the sensor onto the sliding portion of the window or swinging part of the door.  Opening the window moved the magnet away from the magnetic sensor, which cause the contacts within that sensor to become electrically 'open', and the alarm was triggered!  Just that simple!  The sensor was easy to removed, so I took one out and took it with me to Radio Shack, who I knew had a few alarm systems.....they had it, and they were cheap - like $3.00 or so each!  So I bought enough for the house, went home and enlisted my young daughter to help me, and we spent the rest of the day replacing sensors....all of them.  Next I pulled the mother board and went to an alarm company, and they sold me a replacement mother board, along with the installation manual - and that manual is important because it tells you how to set up the mother board. I went  back home, swapped out the mother board, powered it up, did the setup on the motherboard, and bingo - we were in business!  With just a couple of hours of work, plus maybe $200 or less in parts, $20 for my daughter, and I had completely repaired our alarm system, and had pocketed almost $1,400!

When we moved here to Alpharetta GA in 1995 from Brandon, our home was under construction.  I was presented with a contract for an alarm monitoring company and alarm system.  I turned it down - it was out of reason, and felt I could purchase a system later.

When we moved in and were settled, I noticed an alarm box in the basement.  When I opened it up, I was shocked to see a motherboard and all the sensor wires had been pulled.  They weren't connected but were ready to be connected.  The best news was - this was the same system I had repaired in Brandon Fl!

So, you guessed it - it sat there for the next 16 years, and I never got a round tuit (tuits come in round, left and right - as in 'round tuit', 'left tuit', and 'right tuit' - I keep all the 'tuits' hidden from my wife, then I can say - " I will do that as soon as I can get 'a round tuit', and since I know where all of them are, I never get one!).

Link to Part 2 of this article.

Monday, December 19, 2011

Banjo's Easy Shrimp Bisque - Sous Vide



We recently bought a frozen package of shrimp from Costco.  It's labeled as Kirkland's Raw Tail On Shrimp, 21-25 count per pound, 2 pounds.


I've enjoyed using this shrimp in different ways to make different meals.

Today I'm going to make an original - Banjo's Easy Shrimp Bisque - Sous Vide.  It's easy because I'm using 2 cans of Bar Harbor Lobster Bisque as the base, and Sous Vide to cook it.

For those of you not familiar with Sous Vide, it is a water-bath immersion method of cooking utilizing precise temperatures.  For additional insight, see this link.  Since shrimp can easily be over cooked, this is a great utilization of Sous Vide cooking.  Note: there are several ways to cook Sous Vide, and I've done them all.  If you are doing this for home cooking, then have a look at the Sous Vide Supreme, a great home tool.


Servings

  • 2 - 4, depending on whether it's the main course or accompanying other elements.

Time

  • Prep: 15 mins
  • Cooking: 1 hour in Sous Vide (no attention required on your part - put it in and walk away)
  • Total: 1 hr 15 mins



Ingredients

  • 2 cans (10.5 oz each) of Bar Harbor Lobster Bisque.  Note: if you can't find this brand, then look for premium brands of bisque.  It can be lobster, shrimp, or crab.  Lobster is what our local grocery store carries.
  • 6 frozen (or fresh if you are local to a good source!) shrimp taken from 21-25 count shrimp.
  • 1 gallon Heavy Duty Freezer ZipLoc bag.
  • Optional: 1/4 cup cream
  • Sous Vide cooker.
Steps




    Sorry about the goofy alignment of the pictures.  Google Blog isn't giving me much capability to align them with the text.

  1. Preheat Sous Vide to 142dF.
  2. Remove 6 shrimp from frozen shrimp bag.
  3. Place into the ZipLoc bag.
  4. Remove all air from ZipLoc bag.  If not familiar with how to do this, go to youtube.com and view this video.
  5. Submerge ZipLoc into Sous Vide.
  6. Heat shrimp for 10 minutes to thaw - they should be orange-ish in color now. 
  7. Remove shrimp from ZipLoc bag and place onto cutting board.  Retain the shrimp-water that is in bag for flavor in bisque.
  8. Remove tails by pinching meat out while pulling on tail - this extracts all of the meat.  
  9. Discard tails (or you can retain and pull out later - your preference).
  10. Finely chop shrimp.  You want a real-fine grained chop here - pulp is good.
  11. Place ZipLoc bag into large bowl, and bend back the top of the bag so  the lip of bag doesn't get food on it.  The bowl is here to stop any mess while providing support for the bag to remain open while you are adding ingredients.
  12. Place shrimp back into ZipLoc bag.
  13. Add both cans of lobster bisque into ZipLoc bag.  If adding cream, add now.
  14. Close most of bag while squeezing air out of bag.
  15. Carry bowl with bag to sink, and fill bowl with water while preventing bag from filling with water.
  16. Remove all air from ZipLoc bag.  If not familiar with how to do this, go to youtube.com and view this video.
  17. Cook for 1 hour (or more - this is one of the beauties of Sous Vide Cooking) at 142dF.
  18. Serve into individual bowls.
  19. Top with a little cracked pepper, salt to taste.

Tuesday, December 6, 2011

Banjo Daytrading - Trading ES with TICKs

To understand this post, you'll need to know something about Market Profile.  If you aren't familiar with it, then google it - too much required to put here for this entry on trading the TICKS (that's the NYSE TICKS).  I also monitor the change in NYSE volume, and the change in the relative advancing vs declining changes for those stocks.

I have been daytrading the E-mini S&P 500 futures for a while.  Their symbol (concurrent) is ES.  The smallest increment in the ES is a tick (not the same thing as the NYSE TICK), which is 0.25.  A point is 1.00, so it is 4 ticks.

You can buy or sell-short as many contracts as you want, as long as your account balance will support it!  Each tick is $12.50 per contract.  So for 1 contract, 1 tick is $12.50, and 1 point (4 ticks) is $50.00.  If you were swinging for the fences and have multiple years of a proven successful record at trading the ES, then as a professional, you might trade as much as 200 contracts!  At that level, 200 x $12.50 means a single tick would be $2,500, and a single point (4 ticks) would be $2,500 x 4 would be $10,000!


Today I had a total net of -3.5 points.  I started trading around 1:45 pm.


So, while you don't know what I actually made or lost today, since the minimum number of contracts is 1, and 1 tick is $12.50 for 1 contract, and 1 point is $50 (4 ticks), and I lost 3.5 points, then you know I lost at least $175 today.  If I traded 3 contracts, then I lost $525.  And that pro trading 200?  He would have lost $35,000!

As mentioned above, it is my goal to watch the TICKs, along with the changes in the Volume and changes in the Advance/Decline value, as well as the actual ES value.  I like to draw trendlines on the TICKs so I can see the trend in the TICKs, as well as drawing trendlines on the ES.  I keep a loose eye on the simple moving averages (sma) for the 20, 50, and 200 period I have the chart set to.  I like to have a 1 min, 5 min, 15 min and 30 min chart open, all at the same time.  I'm aware of, having previously looked at the daily chart, but I don't keep it open.

Prior to the open, I examine the SPY as a proxy on a weekly basis.  This helps me to see longer term trends that I'm operating under and being influenced by.  I find it much easier, for instance, to observe overall direction, and in particular, the change in SPY volume on a weekly time frame.  I note any new trends or trend continuations, closeness to big SMAs like the 200 dma, 50 dma for turning points that may be induced onto today's environment.  I next look at the daily SPY, for the same reason as looking at the weekly, in particular trying to observe any change in sentiment as indicated by volume, while also noting yesterday's high, low, close, and various MarketProfile values (explained in more detail below).  I then look at a rather broad spectrum of overnight futures to get a flavor of what the world thought was going on overnight, as reflected in the futures, as it will carry over into today for a while until new news comes along to change the world's collective opinion:

  • Markets: ES (S&P 500), TF (Russell 2000), YM (Dow industrials), NQ (NASDAQ)
  • Commodities: (GC (gold), CL (oil), HG (copper), LBS (lumber), ZW ( wheat)
  • Foreign Exchange(FX): DX (US dollar), 6E (Euro), 6J (Japan)
  • Treasuries: ZT (2 year), ZN (10 year), ZB (30 year)


Monitoring and trading the ES
On the 30 minute chart, I like to place a price line for the following elements: the VAH (see MarketProfile), VAL, VPOC, R1, S1, and yesterday's high, low and close.  I'll put yesterday's open on the graph if it's not embedded in the middle of everything.

I monitor every candle on the 1 min, 5 min, and 15 min charts.  I try to evaluate their meaning.  I do the same for the TICKs, and I keep an  eye on the VOL change and the ADV/DCN change.

My Loose Rules for me to trade (these are evolving, and as you can see, my results were negative today, but then, I didn't follow my rules too well today...):

Start the day, get a view of the influences in effect:

  • What does the weekly SPY look like?  What big support/resistance, SMAs, and volume are going to influence today?
  •  What does the daily SPY look like?  Same questions as above.
  • What do the market futures look like?
  • What do the commodities futures look like?
  • What do the FX futures look like?


I Only want to go long if:

  • Near the bottom of a VAL, S1 (or S2,...).
  • TICKs are above neutral, generally above 500, and have been above neutral for a while (or swing positive hard, like to 1000 or more).
  • If more confirmation is needed, I like to wait for the ES to have been hitting resistance for a while, now breaking through.
  • There's been some range to today's trading since open.  I do terrible when the range is suppressed.
  • I like to have a range of at least 4 points, from bottom to top, assuming I can get in somewhere near the bottom of the range.
  • I like to have a range on the VAH-VAL to be at least 4 points too, and try to get in near the VAL.
  • I don't want the VPOC too near to my opening the position, as the ES will frequently stall here for long periods of time.  So, I would prefer that there be at least 2 points, and preferably 3 points or more to the VPOC from my entry point.
  • I don't want the VOL and ADV/DCN to be going against me in my direction.  If I'm going long, I don't want them falling.
Only go short if:
  • Opposite of the above.



Monday, December 5, 2011

Banjo Experiments with Sous Vide Shrimp

I haven't tried any shrimp yet via Sous Vide method (BTW- I have a SousVide Supreme.  I have also created my own cooking vessel using an Arduino to control the temperature, but this looks  a lot nicer in the kitchen.)

This is an experiment, so it may evolve over several iterations.  For this first iteration, I'm using a temperature I found on the internet: 140 dF for 1 hour.  I have misplaced my cook book, so that's the best I can do for tonight.

I've selected 1/2 lb of Kirkland's Fresh Frozen Shrimp, 21-25 count (shells off, tail on, deveined). This means they were frozen immediately on the shrimp boat after being caught, placed into netted bags, and immersed in the cooling brine.  The 21-25 count means that 21 to 25 shrimp would equal 1 pound of shrimp.  I don't know if this means before they were shelled and head taken off, or after this has been done.  At any rate, this is a common method of buying shrimp at a seafood market - it allows you to specify the size of the shrimp.  21-25 count is a nice shrimp size.  It's not a big huge prong, but it's much bigger than popcorn shrimp.  Kirkland's shrimp is the store-brand of Costco.  I've been impressed with their store brand to date.

The recipe for tonight's trial:
1/2 lb frozen shrimp, shell off, tail on, deveined.
3 oz butter
2 tsp Old Bay Seasoning

Steps

  1. set the Sous Vide to 140 dF and allow it to come up to temperature.
  2. While step 1 is completing, place 1/2 pound (this would be 10 - 12 shrimp) into a ZipLock Freezer Quart bag.  
  3. Place butter and Old Bay Seasoning into the bag.
  4. Use the water immersion method and remove air from the bag (or use vacuum seal machine of that's your preferred method).
  5. Set timer (any timer will do...) to 1 hour 15 minutes.
Prep Time: 10 minutes
Cooking time: 1 hr 15 minutes
Total time: about 1.5 hours

Result of 2nd test - 141dF control temperature
We both felt like we liked this temperature better than the 140dF temperature.  Shrimp was slightly more firm.  Both test were conducted using shrimp from the same purchased bag.  We will try 142dF next.  Our intent is to keep bumping up the temperature 1dF at a time until we either don't like it as well as an earlier temperature, or can't detect any change.


Result of first test - 140dF control temperature
Hey!  This wasn't bad!  In fact, they were good!  However, if you think about it, we have all probably been eating overcooked boiled shrimp for most of our lives, just because the temperature control was so difficult.  Since the mass of something determines how long it has to be cooked, and shrimp has a low mass, and most people boil the water (212dF at sea level), then they've been way over cooked.  A shrimp can be represented as a narrow cylinder, with heat being applied from all sides.  Since heat migrates from hot to cold, and the distance from the outer edge to the middle (where the heat would meet the heat from the other side coming in), it doesn't take long for shrimp to come up to temperature.

So the Sous Vide method, or more preciously, an accurately controlled water-bath method, allows us, and for most of us this is the first time, to cook shrimp without overcooking it.

So how did we like it?  Well, considering that for all of our life when eating boiled shrimp, we have been eating over cooked shrimp, and this is the first time ever that we are not eating overcooked boiled shrimp, you should not be surprised to hear we thought the shrimp was under cooked!  Hah!  But I suspect the reality is that we need to recalibrate what we think is the proper temperature to cook shrimp.

Note that since we were cooking at 140dF, we were not cooking boiled shrimp; we would have had to cook at 212dF for it to have been boiled shrimp.

So we cooked the shrimp at 140dF as per outlined above, and we thought we would have preferred them a little more cooked.  In most cooking, you can increase the temperature of the cooked item by allowing it to cook longer.  However, in an immersion bath method, which uses precisely controlled temperatures at extended lengths of time, leaving to food to cook longer won't raise the temperature of the item being cooked - it's already reached the cooking temperature, in this case, of 140dF.  So to increase the temperature of the shrimp, and since leaving it in the cooking water bath for a longer length of time won't increase the temperature, then the only way to raise the internal temperature of the shrimp is to raise the temperature.  So for our next test, I will raise the temperature by 1 dF, to a control temperature of 141dF.

I'll let you know how we liked it!