How to handle goat's milk so it tastes great
Great-tasting goat's milk is not hard to produce, provided you follow the following five essential rules.
goat health
For the best milk, your doe must be healthy. If she is off-feed for any reason, has a rough, dull coat, a cough, a hot udder, or lumpy or bloody milk, her milk should not be used until she has been vet-checked and treated for any illness, parasites, or mastitis. Strictly observe milk-withholding times for any medications she is given.
Regular deworming and mastitis checks, both of which you can do yourself, help to prevent and/or catch problems early so they can be dealt with effectively. Some does prone to mastitis or chronic mastitis may not be clear again until they are dried off and treated with a dry period mastitis antibiotic.
feeding
What she eats can affect her milk flavor. If she's on weedy pasture or has access to plants in the cabbage family, pull her out at least two hours before milking. And while silage isn't the greatest feed for goats to begin with (depending of what it's made of), if they do get some on a regular basis, off-flavor milk can be expected.
utensils/cleanliness
Here is where a lot of problems creep in. All milking utensils and storage containers should be either stainless steel or glass. Period. Aluminum gets scratched and pitted very easily and will then harbor bacteria even with careful washing. Plastics are soft and also prone to harboring bacteria, not to mention that they can leach chemicals into the milk; food-grade plactic jugs can be used temporarily.
All containers, pails and strainers need to be washed thoroughly with soap and water. Antibacterial dish detergent is OK, but avoid anything that's perfumed. A soak and rinse with a dairy sanitizer after washing gets rid of any lingering bacteria but may not always be feasible because of expense. All equipment should be air-dried and completely dry before use.
If you use cheese cloth or duck for straining of milk (or curd), it must be thoroughly rinsed of all residue and then sanitized in boiling water and air dried before use. Commercial milk filters are cheaper in the long run!
technique
If you're unsure of how to milk a goat properly, ask an experienced herdsperson to show you. Pulling and rough handling may cause injury and subsequent udder infections.
Wash the udder with udder wash or germicidal soap and dry thoroughly with a paper towel. Don't use rags, as they will only spread germs. Brush or wipe off any litter, like shavings or straw, from her belly and flanks to prevent the pieces from dropping into the bucket and contaminating the milk.
She should be milked out completely twice a day (you can go to once a day toward the end of her lactation), and the teat ends should be dipped or sprayed with a germicidal teat dip/spray.
cooling
After sanitation, rapid cooling is the next most important factor in producing great milk. Pour the milk through a strainer with at least four layers of dry, sanitized cheese cloth, but preferably with a disposable milk filter; pour into glass bottles or a stainless milk can. Place the bottles/can into an ice water bath for one half to several hours, depending on the amount of milk. If you have more than a gallon or two, lightly agitate the milk every now and then for more even cooling.
A quart (liter) or less can go directly into the fridge; for one thing, it'll get used up fast anyway. A gallon (3.6 liters) can take up to 24 hours to reach refrigerator temperature, during which time all kinds of bacteria (there will always be some) can grow and break down the wrong fatty acids. The milk will also spoil faster.
Small amounts in smaller containers can also be cooled in the freezer. Esp. if you're using glass, set a timer! It's easy to forget, and the expanding milk can break the glass.
other considerations
Milk from breeds or individual does producing low butterfat will need more careful handling and super fast cooling to prevent the wrong fatty acids from affecting the milk flavor. Commercial dairies will often maintain mixed herds for that very reason.
If you're going to pasteurize the milk, you can skip the cooling process and go directly to pasteurizing.
The above suggestions will go a long way toward producing great milk that everyone will love.
Enjoy!