BUTTERMAKING 61 
slowly revolved for at least half an hour so that the lime 
water may thoroughly penetrate the pores of the wood. 
Nothing is equal to the cleansing action of well pre- 
pared lime water and its frequent use will prevent the 
peculiar churn odor that is bound to develop in churns 
not so treated. 
The outside of the churn should be thoroughly cleaned 
with moderately hot water containing a small amount of 
alkali. 
Churning Cream Immediately After Adding the 
Starter. Where much hand separator cream is handled, 
it is usually received with varying amounts of acid, rang- 
ing in some cases from 0.15% to 0.8%. When the 
average acidity of the cream is such that when treated 
with a large amount of starter the mixture will show 
0.5% acid or more, the cream should be churned as soon 
as the proper churning temperature can be secured. If, 
for example, the vat of cream shows 0.4% acid and the 
starter 0.7%, then one part of starter to two parts of 
cream would give an average acidity of 0.5%, the right 
amount for churning cream of moderate richness. 
Pumping Cream into the Churn. Cream may be 
forced into the churn either by means of air pumps, 
sanitary milk and cream pumps, or with pumps working 
on the principle of an ordinary well pump. 
The air pumps require air-tight cream ripeners for 
their successful operation. The air is pumped into the 
ripener to create sufficient pressure to force the cream 
into the churn. Forcing air into the ripener has the 
advantage of permitting the cream to be conducted to 
the churn through an open spout. 
Pumps worked with a handle have the advantage of 
