Calculating PBW ounces to Tablespoons

[RainierViewBrewing]

My search to find out how many Tablespoons vs. Ounces of PBW rendered many DIFFERENT conclusions. So, I went out and bought a digital scale to figure out the answer. However, my results are not close enough to everything I’ve read, so I’ll open this up here for discussion.
The scale I bought resulted in 2 Tablespoons = 1.1 ounces. I’m concerned because another website showed calculations of 1 teaspoon = 1 ounce; there are 3 teaspoons in 1 Tablespoon, so 1 Tablespoon should have resulted in 3 ounces.
I started trying to figure this all out when I kegged my last brew and noticed a rough feel to my conical. A 40 minutes soak of PBW in roughly 100 degree water and a slight scrub with a soft brush did nothing to remove the roughness.
Any help here is appreciated. Thanks for all answers in advance!

Cheers!

 

[505-Brewer]

Your probably finding values for conversion to fluid ounces. I.e. volume not mass? Known density of your material will give you the mass? Also the precision of your balance (and the measuring spoons !!) can skew things a lot w a-cheaper scale.

Check it with water which has a proven density at a given temp. Generally 1 mg/mL. That will give you some insight but wont tell you if its your spoon or your balance still.

Let us know how it goes.

 

[tll77]

Generally speaking, two tablespoons is one ounce.

Three teaspoons per tablespoon, so one tsp is approximately 5 grams.

Your first finding of two tablespoons per ounce(1.1 close enough) was correct.

 

[S-Met]

Dry measurements are better calculated by weight than by volume. A tablespoon of coarse salt vs a tablespoon of very fine salt will result in a significantly different weight. Also need to base the weight to a level tablespoonsince you cannot reliably measure a heaping spoon.

Since weighing is tedious for quick cleaning, calibrate a measuring spoon/scoop. Place a coffee filter on your scale and hit tare to zero out. Pour 1 level scoop and see what it weighs. From the measurement, you can calculate how many scoops are needed. For pbw, having a close enough estimate will be close enough. My guess is that 2 tablespoons is enough.

I would use a higher water temp though, 100°f seems low. I'd think 150 sounds better. Let it soak until cool enough to handle.

 

[oakbarn]

I did my own testing and since it is not rocket science, TLAR (that looks about right) is sufficient for adding PBW.

I got .55 oz per tablespoon.

100 ml beaker held 3.65 oz at 100 mm.

 

[bracconiere]

TLAR (that looks about right) is sufficient for adding PBW.

sounds about right, otherwise you're going to need a base weight for your pots you're cleaning, and figure by mols how much you need to add to perfectly dissolve the grime! lol