INTRODUCTION. 11 



them. Sirup made from some of these treated saps showed all the 

 symptoms of ''buddy sap/' was dark in color, had an "off " taste, and 

 did not resemble pure maple sirup. The sap drawn from the tree 

 under sterile conditions did not seem to contain any bacteria, showing 

 that the contamination must enter from the outside. As a further 

 proof that the inferior color and quality of late run sap are due to the 

 fermentative action of micro-organisms in the spouts and buckets, 

 trees were selected late in the season from which sour sap was being 

 obtained. These were tapped a second time a little way from the 

 original holes and clean spouts and buckets used. From these new 

 tap holes a clean, clear sap came, which boiled to a light colored, fine 

 flavored sirup, while from the old holes came the cloudy sour sap 

 which boiled to a dark, buddy sirup. 



These observations prove the necessity of keeping the buckets and 

 holes clean. By reaming the holes during the latter part of the 

 season souring could be partially obviated, but preferably the hole 

 should be reamed, if three-eighths of an inch originally, with a half- 

 inch reamer at least once in the season and twice if the season is pro- 

 longed. Without these precautions the hole becomes foul from 

 bacterial growth, the flow of sap is retarded, and the flavor is spoiled 

 by souring, as has been noted at the Vermont station. Again, if the 

 sap stops flowing for a few days because of very warm weather, a 

 freeze comes, and more sap flows, new holes should be made to 

 obtain a light-colored sirup. 



The buckets and containers which catch the sap are also an impor- 

 tant element in the production of a light delicately-flavored sirup. 

 Wooden buckets were used altogether formerly, but at present the 

 tendency is toward metal ones. When wooden buckets are used they 

 should be painted inside and out each year, which makes them easier 

 to clean and keeps the sap out of the pores of the wood. When they 

 are unpainted the sap soaks into the wood, and on warm days exposure 

 to the air causes souring, which changes the flavor and always pro- 

 duces a darker colored sirup. This is also obviated by using metal 

 pails, but souring will take place with the very best kind of pail if it is 

 not kept clean. When on passing the finger around the inside of the 

 pail at the bottom a ropy mucous membrane is found, it is to be 

 attributed to bacterial action resulting from uncleanliness. To pre- 

 vent this, the pails should be emptied daily or oftener if possible and 

 be washed carefully after each run. Care in this regard will greatly 

 lighten the color of the sirup. 



The most important point in the selection of the buckets is that 

 they should be carefully covered. To even a casual observer the 

 need of covers for the buckets is obvious, but by far the greater per- 

 centage of the sirup makers do riot use them. A cover keeps out rain, 

 snow, and washings from the trees, as well as dust, insects, dried leaves, 



