Textile consolidation is one of the most technically and ethically awkward procedures in the intervention on ancient fabrics. This treatment always brings up issues about the reversibility of materials and methods, particularly in cases in which the extreme degradation of the fabric requires the application of an adhesive substance to reinforce the fibres and re-establish their consistence from the inside. Sewing systems nevertheless constitute a valid and efficient alternative in the case of slightly deteriorated items that barely need any further minimum reinforcement. Hence, the application of reinforcement pieces by sewing these on is similarly useful in the case of treatments for replacement of missing pieces of the original fabric, where one can see a need for likening both the textile characteristics and their chemical nature, colour, etc. of the items added and the original. The use of natural substances for dyeing fabrics, as is the case of coffee, has been a common practice for years. This work sets out to be a first approach to the use of coffee as a dye and in turn to establish its effectiveness in dyeing silk fabrics used as reinforcement items in textile consolidation processes. This was done by optimizing the dyeing process with this natural colorant, using different recipes from specialized treatises (both as regards direct dyeing methods and those applying a pre-treatment with mordant agents such as alum, potassium dichromate or copper sulphate). Later on, the effects of the different variants in the dyeing processes were assessed by means of colorimetric analysis, optical microscopy and electronic microscopy (SEM/EDX). The results obtained establish that an optimum range of tones very similar to historic silk fabrics has been attained, thus meaning that these can be used in textile consolidation treatments.