178 CoNbENSED BUTTERMILK 
In order to stop this waste of buttermilk in summer, to utilize 
it economically and = profhtably and to equalize the supply 
throughout the year, some of the large creameries of the coun- 
try have found it practicable and profitable to condense the sur- 
plus buttermilk. Information from chicken feeders and hog 
feeders shows that, when re-diluted to the consistency of the 
original buttermilk. this condensed buttermilk gives equally as 
satisfactory results as the fresh buttermilk. 
Prior to the great war the market value of buttermilk and 
of condensed buttermilk was considered too limited to justify the 
relatively high manufacturing expense, incident to the concen- 
tration of buttermilk by evaporating from it a large portion of 
its water. But the food and feed shortage, together with the 
high prices brought about by the war and since the war, neces- 
sitated the more general use of byproducts and raised the valua- 
tion of buttermilk to figures that render its manufacture into 
condensed buttermilk highly profitable. 
Manufacture.—There are several methods whereby butter- 
milk can be and is being commercially reduced in volume. The 
most common of these are: Removal of water by gravity, re- 
moval of water by centrifugal separation, removal of water by 
evaporation, either in vacuo or under atmospheric pressure. 
Removal of Whey by Gravity.—Much of the so-called con- 
densed buttermilk that reaches the market is not the result of 
evaporation of a portion of the water contained in the butter- 
milk, but is produced by permitting the curd to settle by gravity 
and then drawing off and rejecting the whey. 
In this case the fluid buttermilk is pumped into a wooden 
tank, either a horizontal vat or a vertical stave tank. The tank 
usually contains several outlets with gates, located at different 
heights, to facilitate the removal of the whey. The tank may 
or may not be equipped with steam pipes for heating. The but- 
termilk is heated to boiling point in these tanks either by blow- 
ing live steam into it, or by running steam through the pipes 
installed in the tank. ‘This heat is maintained for several hours. 
This causes the casein to contract and settle to the bottom in the 
form of fine particles of curd, leaving on top a clear whey. ‘This 
whey is drawn off through the gates located above the stratum 
