Syrup level dropping in bottle after it cools???

[danielschauder]

Is it normal for the syrup level in a bottle to drop after it cools?

Details:
Glass bottles, 12 oz, 16 oz and 32 oz glass bottles.
Plastic caps both flip top and non flip.
Bottled at 185 degrees and laid on its side for about 1 minute.
Syrup density is 66.5 brix.

So I filtered approx. 7 gallons into my water jacketed canner. Did a final density test at 185 degrees with my refractometer and it read 66.5 brix. Bottled mostly 32 ounce and a few 12 and 16 ounce glass bottles. All the bottles were filled to a 1/4" below the threads for the caps. The bottles were then laid on their sides for approx. 30 seconds to 1 minute. I placed the filled bottles on a stainless cart with a couple inches between every bottle. This process is our usual process and it has always worked for us.

The next morning I noticed that all of the syrup in the bottles had dropped about 1 inch in the 32 ounce bottles and about 1/2 inch in the 12 and 16 ounce bottles. I opened one of the bottles and the seal did do its job and I heard an audible pop when I opened the seal.

Is this normal?? I guess I never noticed it in the past but that doesn't mean it never happened. If that is normal, won't the density change? It can only be evaporation which I'm not sure how that is possible in a sealed bottled. Am I missing something?

[Super Sapper]

It is normal, 66.5 brix is for 60 degree syrup I think. If you have an hydrometer you will see a hot and cold line because the density does change with temp.

[RIVERWINDS]

Correct, they will "shrink" after cooling down. Just sat in a seminar about this. Hot fill is to the neck rib on most glass. But also by filling it this far you're giving away product. I want to say a quart glass bottle filled to neck yielded 33+oz cooled product. His presentation was based on syrup in the high teens $$ per quart retail, and at that rate he was giving away 90 cents of product. It was something we all face, where did all my syrup go? I started with 10 gallons but only yielded so many quarts. He was trying to explain that properly hot filling syrup containers gives away valuable product and your pricing needs to reflect that. The smaller the container the more product you're giving away.

[jmayerl]

Let's go back to grade school physics. Heat expands , cool contracts.

[danielschauder]

Let's go back to grade school physics. Heat expands , cool contracts.

So 12 ounces by volume of cold syrup is 13 ounces by volume of hot syrup? I guess I missed physics in grade school.

[buck3m]

Hot syrup does shrink a lot as it cools!

I think it's important to recognize that there are fluid ounces, which are measured by volume, and "scale" ounces which are a unit of mass. For example:
1 cup maple syrup = 8 FL. oz = ~11.2 oz.

I once came up with these calculations:
A full gallon of maple syrup should weigh 11 pounds 3.2 oz plus the weight of the container.
A half gallon should weigh 89.6 oz, or 5 lbs 9.6 oz., plus container.
A quart should weigh 44.8, or 2 lbs, 12.8 oz, plus container.
A pint should weigh 1 lb, 6.4 oz, plus container
A 12 fluid oz bottle should weigh 16.8 oz, plus container
An 8 oz (1 cup) bottle should weigh 11.2 oz plus container
A 4 oz container should weigh 5.6 oz plus container

I based all that on this source:
One gallon of maple syrup at 67º Brix weighs about 11.2 pounds...Weight measures are more accurate and repeatable than volume measures.
http://www.nnyagdev.org/maplefactsheets/CMB%20205%20Replacing%20Table%20Sugar%20with%20Map le%20Sugar-1.pdf

[markcasper]

Correct, they will "shrink" after cooling down. Just sat in a seminar about this. Hot fill is to the neck rib on most glass. But also by filling it this far you're giving away product. I want to say a quart glass bottle filled to neck yielded 33+oz cooled product. His presentation was based on syrup in the high teens $$ per quart retail, and at that rate he was giving away 90 cents of product. It was something we all face, where did all my syrup go? I started with 10 gallons but only yielded so many quarts. He was trying to explain that properly hot filling syrup containers gives away valuable product and your pricing needs to reflect that. The smaller the container the more product you're giving away.
Amazing that we have to have seminars for something that should have been learned in grade school! Quite aware of the containers holding too much syrup, but I don't like being asked by customers why they are getting shorted. Have to find a happy medium. Quite apparent in some syrup I've seen for sale that they are indeed being stingy.

[danielschauder]

[QUOTE=buck3m;334203]Hot syrup does shrink a lot as it cools!

Thanks, this was the simple answer I was looking for.

I understand the difference in weight versus volume even though I didn't even graduate kindergarten.

[bstewar]

I have always filled my sugar hill jugs about 1/4 - 1/2" from the top knowing it will cool and drop. I want my customers to have full containers so they keep coming back. More of a hobby for me so I don't mind sacrificing a few ounces to make customers happy.