Butter Making

Butter making process

Butteroil or Anhydrous Milk Fat (AMF)

Ghee

Buttermaking expert and butter making equipment

Butter is made from milkfat (cream) usually separated from the milk to 40% fat and then aged overnight (approx 12 hrs) in a controlled temperature and gently agitated tank (Ageing tank) at approximately 8C to 12C.

The cream ageing process for buttermaking allows the fat to partially crystallise.During the crystallisation process a chemical reaction takes place and heat is released causing a temperature rise in the cream (Latent heat of Crystallisation) hence the necessity for gentle agitation and controlled temperature. The slightly elevated temperature during ageing together with gentle agitation allows the fats to move in the emulsion and to crystallise together giving larger fat globules which will break more easily during the Butter churning process. If the cream is too cold then the fats will not move and crystallise as easily as they will be too viscous. Without gentle agitation then the fats close to the tank edge will cool more than the fats in the centre of the tank giving an uneven crystallisation. The quality and gentle handling of the cream is critical to ease of manufacture of butter and also the yield of butter achieved. If the butter or cream is over pumped then this can damage the fat globule membrane (lecithin layer) releasing free fatty acids which will be lost to the buttermilk.

The better the control of the cream fat % and the temperature of cream fat crystallization, the more consistent the butter should be, so for volume manufacturing with continuous buttermaking, attention to detail is critical to ensure optimised yields.

A 1% variation in moisture and salt content due to processing variation can be very costly to manufacturers as the legal imit of 16% can not be exceeded so the moisture loss is a physical loss of profit / yield.

Continuous buttermakers ideally would have a cream tempering section which would preheat or precool the cream to a consistent controlled temperature to feed to the continuous buttermaker to ensure process consistenty.

The cream feed rate to the continuous buttermaker should also be controllable.

The continuous buttermaker would ideally have cooling on the barrel and also a facility to recycle back to the tank in the event of a stoppage or breakdown.

Salt is generally dosed in a water / slurry form into the working section of the buttermaker.

Buttermilk can be partially recycled to the working section when required but generally it is passed theough a sieve to recover fines and grains and separated, pasteurized or simply spray dried and sold as buttermilk powder.

Some manufacturers will add back a small quantity of buttermilk (5%), pasteurized back to the raw milk silos where it is then reprocessed in the usual way with the raw milk and this can reduce wastage / losses but care needs to be taken that this does not contravene any finished product specifications.

The butter exiting from the barrel can go direct to a packing machine or into a buffer tank prior to the packing machine.

Bulk butter is generally filled into a coloured polythene liner directly into a cardboard box (bulk 25kg) after which it is sealed, coded and dated and put either into chilled storage or more frequently into frozen storage with sample boxes kept until the next day for butter grading.

Butter grading is carried out for a number of parameters; free moisture, greasiness, salt, taste and appearance basis ensuring a smooth finish (butter grading is quite specialist and we can instruct you on how to do this as it requires demonstration)

Once laboratory results on yeasts and moulds, coliforms, moisture and salt etc. are available these are matched with the grading results and the is butter released, as appropriate.

The shelf life on chilled butter is generally about six weeks but butter can be frozen for a year and then packed for retail sale with a six week chilled shelf life.

One of the biggest risks to manufacturers is Yeast and moulds and coliforms so attention to detail is required in manufacturing controls. Yeasts and moulds are ubiquitous in the atmosphere and for high volume manufacturers it will be critical to have clean filtered overpressure air in the buttermaking and packing rooms

In the EU cream would generally be pasteurised at about 80c, but in developing countries it is sometimes higher due to higher levels of contamination. Bulk butter is generally stored frozen at below -18C for up to 12 months prior to defrosting / tempering to a suitable temperature for packing. The shelf life of the retail packed chilled butter will generally commence from the packing date and not from the produiction date. The chilled shelf life of butter will usually be up to six weeks. Cleanliness of the outer wrapper / packaging is also critical to shelf life as any grease on the outer wrapper will result in yeasts and mould growth resulting in the potential for contamination of nearby products.

Butter variants

• Unsalted sweet cream butter
• Salted butter (usually 2 to 4% added salt)
• Acidified or cultured cream butter
• Flavoured butter
• Butteroil