My sourdough is too holey

I know many people prefer a holey crumb but I don't have much space to spread butter or hold a sandwich together. I followed Joshua Weissman's beginner sourdough recipe. I only deviated by not doing my bulk fermentation in a warm environment. My house isnt kept at a warm temperature and I didn't put it my oven with the light on thoughts? via /r/Sourdough https://ift.tt/2XJ5Rzb