Measuring LME

Correct. The actual value is 4.031% expansion from 20 C (68 F) to 100 C (212 F) at standard air pressure (the values also change slightly according to air pressure). Some online calculators assume a straight line increase, but the trend actually curves quite significantly.

A fourth or fifth degree polynomial curve fits quite well. I use a fifth degree polynomial equation in my estimates (for the expansion or contraction between any two temperatures), and the resulting values are quite close. The fourth degree polynomial fit is quite good for temperatures above room temperature, but not so good for temperatures below about 70 F.

 

I weighed a few Maillard Malts cartons from Midwest supplies about a year ago and actually found them to be under 6lbs. I forget the exact amount they were off, but it was 3 or 4 cartons and each was under. If it was a few under, a few over I'd just chalk it up to normal fill variations. They were still sufficiently cheaper than my alternatives that I didn't complain, but I'd be surprised to see the gravity come out high. Of course, I haven't weighed and cannot comment on other manufacturers cartons.

The calculations we're all making assume a certain original sugar density/concentration in the LME. Maybe there is enough batch variation in the production of LME to account for this difference?

 

Could it be that when Midwest are making their batch of extract syrup, and they end up a few points stronger than expected, they make up for it by shorting the weight in the container?

 

Yup, assumptions will get you very time.

Cheers!

 

Read the above messages where the variation WAS taken into account. See Message #4 in particular.

 

Ah, I see. I read the thread this morning but didn't have a chance to reply. Then came back and started brainstorming from my flawed recollections of the post.

 

On the website they were branding the product as Briess LME, but shipping it in Maillard Malts containers. I figured they're buying bulk Briess & repackaging it for resale. Nothing wrong with that, and maybe they had exact numbers on the strength of that particular Briess batch and it was high, but I don't think they should reduce the weight of the product sold without telling the consumer. If it was clear that they were selling me X lbs of fermentable sugars which in theory could come as 6lbs at one concentration or 5.9lbs at a higher concentration, fine. But they're selling 6lbs of LME at a certain concentration range which might understandably vary batch to batch. Though again, it didn't matter enough to me to do more than make a mental note. I haven't bothered weighing any cartons of theirs or any other manufacturer's LME since.